Agathis vs. Hymenaea – trapping biases to interpret arthropod assemblages in ambers

Agathis vs. Hymenaea – trapping biases to interpret arthropod assemblages in ambers | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Agathis vs. Hymenaea – trapping biases to interpret arthropod assemblages in ambers Mónica M. Solórzano-Kraemer, Antonio Monleón-Getino, Enrique Peñalver, and 9 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6999659/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 06 Nov, 2025 Read the published version in BMC Biology → Version 1 posted 3 You are reading this latest preprint version Abstract Background The genera Agathis (Coniferales: Araucariaceae) and Hymenaea (Fabales: Fabaceae) contain resin-producing tree species that are crucial for actuotaphonomic studies. While certain Cretaceous ambers likely originated from Agathis or Agathis -like trees, Hymenaea is the primary source of many Miocene ambers. Field studies were conducted in New Caledonia and Madagascar, to collect Defaunation resin (resin produced after 1760 AD (Anno Domini)). Arthropods were collected with yellow sticky and Malaise traps in New Caledonia, Madagascar and Mexico. Cretaceous and Miocene ambers, copals (2.58 Ma to 1760 AD), and Defaunation resins from various regions were analysed to compare arthropod trapping patterns. Results Actuotaphonomic results show lower number of arthropods trapped in Agathis Defaunation resin, with a non-uniform distribution, compared to the abundant and uniformly distributed arthropods trapped in Hymenaea Defaunation resin. The lower number of arthropod inclusions in the trunk resin of the Agathis trees is attributed to the rapid polymerisation of that resin. Under the same experimental conditions, the arthropods in Agathis Defaunation resin plot far from the arthropods collected in the yellow sticky and Malaise traps, while the arthropods in Hymenaea Defaunation resin plot close to the arthropods in the yellow sticky traps. Conclusions These findings confirm different resin trapping patterns between Agathis and Hymenaea , with significant implications for interpreting the amber record. The fauna trapped by Hymenaea resin closely resembles the arthropod biocoenosis that live in and around the trunks, indicating autochthony and close relationship with the forest ecosystem, unlike Agathis resin. These results improve our understanding of arthropod trapping biases in resin and lead us to reconsider previously proposed interpretations of Cretaceous forest biocoenoses. amber actuotaphonomic studies Cretaceous Miocene biocoenosis taphonomy copal Defaunation resin Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Background Amber is a fossil plant resin, that sometimes preserves inorganic inclusions such as water or soil particles, and a high diversity of bioinclusions, such as phloem sap, plant remains, microorganisms, invertebrates (with arthropods being the most abundant) and vertebrate remains, providing a unique window into biocoenoses in ancient forested ecosystems [1–4]. In the Cretaceous period, conifers were globally the primary contributors to sedimentary deposits of resin (today amber) [5]. Several families have been proposed as the producers of large quantities of resin at that time, namely Araucariaceae, Cupressaceae, Pinaceae, Podocarpaceae and the extinct Cheirolepidiaceae [6–9]. Moving to the Eocene epoch, amber deposits were derived from conifers and angiosperms. For example, Eocene Baltic amber originated from a conifer tree of the family Pinaceae and/or Cupressales: Sciadopityaceae [10, 11], while Cambay (India) amber was linked to the angiospermous Dipterocarpaceae [12]. Conversely, the majority of Miocene ambers, copals, and Defaunation resins ( sensu Solórzano-Kraemer et al. [13]) were derived from angiosperms, predominantly of the families Fabaceae and Dipterocarpaceae [13, 14]. The Cretaceous, Paleogene and Neogene periods are the most prolific in terms of described amber deposits [5, 13]. However, a difference has been noted in unbiased collections between the amber that originated from conifers and that from angiosperms. Of the approximately 500 Barremian amber localities known in Lebanon, only 38 contain arthropod inclusions [15, 16]. Similarly, of the more than 140 Albian amber localities in Spain, only 11 contain arthropod inclusions [17, 18]; of these, four are poor and contain only one or two arthropod inclusions. Another example is the Albian ― Cenomanian French amber, with 60 reported localities, of which 14 contain arthropod inclusions, but only one, Archingeay-Les Nouillers, was reported as highly fossiliferous [19–23]. Cretaceous amber from Southern America seems to exhibit a similar circumstance, as arthropod inclusions have remained elusive despite many years of intensive searching [24–26]. Only 21 terrestrial arthropods in Ecuadorian Albian amber are known until now from South America [27]. It is important to consider that many Cretaceous amber deposits mentioned in the literature contain only an anecdotal amber record. Deposits with significant amber quantities are scarce [5], and researchers primarily focus on amber-rich deposits when searching for arthropod inclusions. On the contrary, Cenozoic amber localities (from the Paleogene and Neogene) appear less abundant than in the Cretaceous, but nearly all contain arthropod inclusions [13,28]. However, the inclusion density, i.e. the number of specimens per volume or mass of inspected amber, has never been studied before. These observations raise question on whether the difference in arthropod inclusions is due to a different distribution of fauna in the ecosystem or a different trapping bias of the resins. Resin has been defined as an entomological trap that works similarly to commercial yellow sticky traps [29, 30]. The fauna living in and around the resin-producing trees of Hymenaea Linnaeus, 1753 has been described as having a greater chance of being trapped and preserved in the resin (the so-called thanatocoenosis or death assemblage), than the fauna living in surrounding areas of the forest [30]. Some resins often contain inclusions that are closely related to the habitats provided by resiniferous trees. Diptera is an order that contains a high number of inclusions in amber. Most of these insects are fungivores, carnivorous, necrophagous, or hematophagous, which explains why they are commonly found as amber inclusions [30]. Agathis Salisbury, 1807 (Araucariaceae) and Hymenaea (Fabaceae) genera contain resin-producing tree species serving as pivotal models for actuotaphonomic investigations in this respect [29–32]. The genus Agathis is primarily distributed today in the Southern Hemisphere , growing in tropical environments across the Malay Archipelago (Malesia), the islands of the South-West Pacific (Melanesia), northern New Zealand, and South Queensland in Australia [33]. Agathis or Agathis -like trees have been postulated to be the source of certain Cretaceous and Cenozoic ambers from Lebanon (Barremian), Spain (Albian), France (Albian-Cenomanian), Myanmar (Cenomanian), Australia (Turonian–Campanian), and New Zealand (Oligocene and Miocene), while there is certainty that Agathis was or is involved in the origin of the copals and Defaunation resins from New Zealand and New Caledonia [3, 13, 34, 35]. Hymenaea is a tropical and subtropical resin-producing tree originating in East Africa during the early Miocene, mainly distributed throughout central and South America, and East Africa (including Kenya, Tanzania, Mozambique, Comoros, Madagascar, Mauritius and Reunion Island) [36–39]. The genus Hymenaea has been identified as the source of the ambers from Ethiopia, Mexico, Dominican Republic (all Miocene in age), Pleistocene and Holocene copals, and Defaunation resins from East Africa, and Central and South America [13, 39, 40]. Understanding why many amber deposits are poor or devoid in arthropod inclusions, and why this holds true for Cretaceous deposits more than for Paleogene and Neogene ones, would contribute to a better interpretation of oryctocoenoses (fossil assemblages) based on amber records. We have thus carried out a comparative actuotaphonomic study based on Agathis trees from New Caledonia and Hymenaea trees from Madagascar. We followed the same experimental protocol as in a previous study based on Hymenaea from Madagascar [30] in order to compare the results. Our aim was to quantify, using statistical analysis, the differences in the intensity of arthropod trapping between the resin exuded by two different resin-producing trees ("gymnosperms" exclusively conifers vs. angiosperms) in their natural environments, with a view to applying the conclusions to the reconstruction of deep-time environments based on fossil assemblages preserved in amber. Results Trapping patterns of arthropods in ambers, copals and Defaunation resins from Agathis , Agathis -like, and Hymenaea trees Fig. 1 can be placed here In the Defaunation resin obtained from Agathis in New Caledonia (Additional file 1: Fig. S1), a total of 48 arthropod inclusions were found in 2,618.7 grams of resin (Table 1), mostly Acari, Pseudoscorpiones, Collembola and non-flying Hymenoptera, namely Formicidae, but also a Thysanoptera and a Diptera remain. This scarce number of arthropods in Agathis Defaunation resin was unexpected, particularly considering the significant number of arthropod inclusions (~4,000) found in 2,300 grams of Malagasy Defaunation resin from Hymenaea (Table 1, see Additional file 2 for a detailed list of arthropod inclusions). We observed a visible divergence in arthropod trapping efficiency (Fig. 1). Here, efficiency refers to two things: First, it refers to the increased trapping of arthropods and other organisms by both ancient and modern resins. Second, it refers to the recording of a more complete (varied) assemblage that better reflects the communities that inhabited these ancient and modern forests. We also observed a visible divergence in arthropod trapping patterns, represented in Fig. 2, between Agathis and Agathis -like, and Hymenaea samples (including ambers and copal from both types of trees). When comparing arthropod counts with resin mass, two different trends emerge: With the increase in resin mass, the pattern of Agathis and Agathis -like samples show a slow, near-flat increase. Meanwhile, Hymenaea samples show a sharp increase, indicating markedly higher trapping efficiency. Fig. 2 can be placed here The different arthropod trapping patterns observed in the Hymenaea and Agathis Defaunation resins are revealed not only by the number of arthropod inclusions per mass of resin (Fig. 2), but also by the probability that a collected Defaunation resin piece/lump with a certain mass does not have any inclusions. The thanatocoenosis (death assemblages) varies greatly between that of Agathis Defaunation resin and that of Hymenaea Defaunation resin, which will considerably influence the interpretation of the resulting oryctocoenosis. The probability density function (PDF) of resin pieces lacking arthropod inclusions was analysed in relation to mass for Hymenaea (Madagascar) and Agathis (New Caledonia) Defaunation resins (Fig. 3). The distributions for both types of resin followed a power-law trend, with exponents of b = -1.97 and b = -3.34 for Agathis and Hymenaea , respectively. The exponent b is a measure of distribution uniformity: values closer to zero indicate greater variability, while more negative values suggest a system approaching uniformity (an explanation of PDF and the degree of uniformity is presented in the Additional file 1). For Hymenaea , the probability decreases rapidly as the mass increases; for Agathis , however, the decrease is gradual. This reflects the fact that large Agathis pieces lack arthropod inclusions. The rate at which the probability decreases reflects the distribution of arthropod inclusions. A uniform distribution leads to an exponential decrease corresponding to an infinite exponent b, whereas a distribution in which all inclusions are concentrated in a single location would have an exponent of b = 0. Thus, the value of b serves as an indicator of the uniformity of the distribution of arthropod inclusions in amber. If the only difference were a lower arthropod density around Agathis and both resins trapped them equally, the lines would have the same shape but offset from each other and they would appear parallel. Therefore, the different values of b for each collection of pieces of Defaunation resin show that Hymenaea resin traps arthropods more efficiently and more uniformly than Agathis resin (see also Additional file 1: Fig. S1 and extended material and methods in Additional file 1). In other words, the characteristics of the thanatocoenosis are very different for each type of resin under investigation here. Fig. 3 can be placed here Arthropod trapping patterns including yellow sticky and Malaise traps The significant difference in arthropod trapping patterns observed in the Defaunation resins raises questions about the trapping efficiency of other entomological traps we used, which were placed: i) on the trunk and ii) close to the same tree species. These include yellow sticky traps, which resemble the sticky resin, and Malaise traps – both of which are used for arthropod collection and actuotaphonomic studies [29, 30, 41, 42]. Therefore, to better understand the trapping patterns and to assess whether Agathis tree resin traps arthropods in a similar way to yellow sticky traps, we analysed their arthropod assemblages using multidimensional scaling (MDS) with Bhattacharyya distance, in order to visualise the relationships between the taxa based on their frequency data. An important result is that the arthropods (at the order level) in the Agathis Defaunation resin, collected from the tree trunks in New Caledonia, plots far from the arthropods (at the order level) collected in both the yellow sticky and Malaise traps placed on the trunk and close to the Agathis trees, respectively (Fig. 4A) (in the Additional file 2 we present the arthropod list). The arthropods (at order level) trapped in the yellow sticky traps in New Caledonia plotted far away from the arthropods trapped in the Malaise traps, but also far from the yellow sticky and Malaise traps from other sampling places, such as the Hymenaea forests in Madagascar and Mexico (Fig. 4C), where the Hymenaea trees were also sampled [29, 30]. In contrast, the samples from Hymenaea trees in Madagascar, analysed using the same method, plots the arthropods (at the order level) in the Hymenaea Defaunation resin from the tree trunks close to the arthropods collected in the yellow sticky traps (Fig. 4B). Fig. 4 can be placed here Families in Diptera deserve a special analysis below the order level, attending to their high abundance in the collected material and in general in amber [43]. In the yellow sticky traps placed on the trunkof Agathis, Diptera made up more than 60% of the total. Within the Diptera, the family Phoridae comprised nearly 90% (Additional file 1: Fig. S2). At family level within Diptera, the yellow sticky traps placed on the trunkof Agathis from New Caledonia plot far away from all other samplings whether they were related to Agathis or Hymenaea (Fig. 4D). The assemblage of trapped arthropods includes Acari, Collembola, Hemiptera, Thysanoptera, Hymenoptera, and Coleoptera, among other taxa (see Additional file 2 for arthropod list). The differences between flying and non-flying insects present in amber, copal and Defaunation resin are not significant among the studied samples, except for the arthropods from the Malagasy Defaunation resin of Hymenaea and those from the Australian Eocene amber (Additional file 1: Fig. S3). We also categorised the arthropods found in all the ambers, copals, and Defaunation resins originating from Agathis or Agathis -like trees and Hymenaea trees, and the arthropods trapped by yellow sticky and Malaise traps in the Agathis and Hymenaea forests (see Additional file 1 and 2 for details of the material and the lists of arthropods, respectively) using a hierarchical clustering (Fig. 5). Agathis and Agathis -like resins (Defaunation resins and ambers, respectively) cluster together at the order level and at family level in the case of Diptera (due to the high prevalence of the order Diptera in most samples, their families were analysed separately). Conversely, for New Caledonia, arthropods from both yellow sticky and Malaise traps placed on and close to the Agathis tree trunks, respectively, cluster together with those from amber, copal and Defaunation resin derived from Hymenaea , as well as with the arthropods from both yellow sticky and Malaise traps on and close to the Hymenaea tree trunks. As an additional result, we have updated the list of unbiased amber inclusions from various localities that can be used in future investigations (Additional file 2). Fig. 5 can be placed here Discussion The number of amber localities lacking arthropod inclusions is unknown for most amber-bearing regions. This is due to the fact that palaeontological research focuses primarily on systematics and taxonomy, and on palaeoautecological information provided by the bioinclusions, in an attempt to reconstruct forest biocoenoses in deep time, while other aspects of the amber and amber deposits, such as taphonomy and geology, remain unstudied or poorly studied. It is also important to mention that a large number of arthropod inclusions were yielded from some amber deposits discovered several years ago and worked for a long time. Peñacerrada I, for example, is notable for yielding the greatest number of arthropod inclusions from Spanish amber [18, 44]. Notably, it is also the locality from which the most amber has been extracted and prepared (see Table 1). The same is true for the Albian–Cenomanian amber locality from south-west France at Archingeay-Les Nouillers. Recently discovered deposits such as the Eocene amber from Australia or the Miocene amber from New Zealand, produced by Agathis , currently contain only a few arthropod inclusions [35, 45]. Thus, for some deposits, the absence of arthropod inclusions is most likely due to collection bias. However, it is clear that the majority of the Cretaceous amber deposits does not contain arthropod inclusions or are extremely poor [5]. Some authors have suggested that this circumstance for many Cretaceous amber deposits may be explained by a much more abundant resin exudation under confined conditions in the underground than in aerial conditions [46]. Araucariaceae trees, particularly Agathis spp., are known for their comparatively abundant production and exudation of resin, not only on their tree trunks, but also within their root systems [3, 37, 47, 48, 49]. In contrast to the hundreds of arthropod bioinclusions described from Malagasy copal and Defaunation resin [39], the copals found in regions like New Zealand and New Caledonia (own field. obs.) lack such abundant inclusions, and no arthropod bioinclusions have been described from this material. This can be partly explained by the fact that root resin is unlikely to trap arthropods in confined conditions; given the abundant production of root resin and the resulting mixture of aerial and root copal in these geological deposits, a large proportion of the collected pieces are of the root type. When examining the extant roots of Hymenaea trees and their resin production, a distinct contrast is evident (Additional file 1: Fig. S4). The resin in Hymenaea roots appear intricately interspersed in the sand, forming a crust around the roots ([39] fig. 8). In Madagascar, we observed large Hymenaea trees that had been uprooted by hurricanes, showing their root systems with only small amounts of resin, unlike large resin lumps commonly formed by Agathis roots [49]. In New Zealand, we have also had the opportunity to study the root systems of large Pleistocene Agathis at Waipapakauri [49] and Bayleys Beach localities. These large trees are exhumed for their trunk wood, but the roots are abandoned, allowing us to observe large amounts of copal associated with roots (Additional file 1: Fig. S4C, D and E). To explain the exudation of resin on the tree trunk and the capability to trap arthropods, it is important to note that resin exudation, in general, archives a variety of possible defensive actions, for example, to shield trees from threats such as bark beetles and herbivores, as well as to facilitate wound healing, preventing fungal and bacterial infection, or to prevent desiccation [2, 5, 48, 50, 51]. The variation in resin composition plays a prominent role in those defensive actions. In performing those defensive actions, Hymenaea resin has been also demonstrated to accidentally act as a kind of entomological trap, more precisely as yellow sticky traps that works better for some arthropod groups than for others [29, 30]. Consequently, scientific interest in amber, copal and Defaunation resin has been primarily focused on arthropod inclusions [13]. However, the absence or fewer number of arthropod inclusions in many amber deposits, especially those of Agathis or Agathis -like origin, has never been questioned. The very few arthropod inclusions in Agathis Defaunation resin compared to the large number of arthropod inclusions in Hymenaea Defaunation resin, along with the different values of exponent b (measure of distribution uniformity) for each resin assemblage, shows that Hymenaea resin is more efficient at trapping arthropods than Agathis resin and does so spatially more uniformly (see also Additional file 1: Fig. S1 and extended material and methods in Additional file 1). This is consistent with our observations in amber. All arthropod inclusions recorded so far in amber originated from Agathis or Agathis -like trees were found in a few pieces/lumps (non-uniform), whereas arthropod inclusions in amber originated from Hymenaea trees are more uniform (Additional file 1: Fig. S1), which means that there are more pieces with at least one inclusion. The fewer arthropod inclusions and their non-uniform distribution in Agathis and Agathis -like resins compared with those observed in Hymenaea resin can be explained mainly through two different aspects, namely 1) resin composition and 2) arthropod attraction or repulsion, hereafter discussed more in detail. Resin composition The variation in resin chemical composition between plant species affects the physical properties of the different resins, namely viscosity or stickiness, and consequently the capability to trap arthropods [28, 34, 37, 52]. Resin is a complex mixture of volatile compounds, including mono- and sesquiterpenoids, diterpenoids, and sometimes triterpenoids. The diterpenoids originate mainly from conifers (gymnosperms), while triterpenoids (e.g., of the oleanane, ursane and lupane series) and sesquisterpenoids come from angiosperms [53]. These compounds contribute to the fluidity (sesquisterpenoids) of the resin, and determine also its grade of viscosity (diterpenoids) [34]. Agathis and Hymenaea resins differ in their chemical composition. Agathis produces a resin type primarily composed of terpenoids [54]. In contrast, Hymenaea produces a resin containing both terpenoids and gum components [37]. The hardening and polymerisation of resin hinge on the number of free radicals within non-volatile compounds, particularly labdatriene diterpenoids, abundant in Agathis species [34, 55, 56]. The effectiveness of resin as a defence mechanism under biotic and abiotic environmental stress depends on factors such as drying, flow rate, and viscosity. These factors determine, for example, whether arthropods are pushed out or trapped on the tree trunk, whether a microbial infection can be stopped, or whether desiccation can be prevented. In general, our observations show distinct drying and viscosity characteristics for Agathis and Hymenaea resins. This suggests that the faster polymerisation of Agathis resin, resulting in rapid drying (see Fig. 6C), likely leads to fewer arthropods being trapped. Conversely, the characteristics of Hymenaea resin imply an abundant trapping of biological remains (Fig. 6D–I). According to our observations, both resins are fluid at the time of exudation, Agathis even more than Hymenaea . However, this changes quickly as Agathis resin dries faster than Hymenaea does . Whether an arthropod gets stuck depends on it passing by just as the tree begins to produce resin and the organism walking or flying close enough to be trapped. It is quite likely that the fast-drying nature of Agathis resin prevents arthropods from sticking to it (Figs. 1 and 6). The previous idea aligns with the sensitivity of Agathis spp. trees to the Phytophthora spp., a water- and soil-borne oomycete primarily affecting these tree species. This sensitivity prompts a substantial production and exudation of resin as a defence mechanism [3, 5, 57]. In consequence, the trees, both their trunks and roots, are producing large amount of resin. It has been hypothesized that rapid resin hardening may prevent the rapid spread of pathogens on the trunk of a tree [37, 58, 59]. However, Agathis is also attacked by the defoliating coccids, trips and boring beetles, among others [60]. Therefore, resin exudation in Agathis is not always induced by a pathogenic agent. On the other hand, in most angiosperms, including Hymenaea, the resin is mixed with gum (a mixture of hydrophilic polysaccharides), which increases the water-holding capacity of the tissues and prevents desiccation [37, 48, 54]. Gum is rarely observed in conifers and not found in Agathis spp. [32]. The hydrophobic nature of gum increases the stickiness of the resin, as gum can form bonds and stick when it comes in contact with oily surfaces [61]. This may partly explain why the resins produced by some angiosperms remain sticky for a long time. Fig. 6 can be placed here How quickly the resin dries depends mainly on the polymerisation rate (low polymerisation rate implies a liquid and sticky resin for a long time), and how long the resin can trap arthropods depends on how long it takes to dry. Therefore, regardless of the amount of resin exudation, the resin will trap arthropods on the entire surface of the accumulated resin for a longer time, making the distribution of arthropod inclusions more uniform (Additional file 1: Fig. S1B), as is the case of Hymenaea resin (Fig. 6D–I). A resin with a high polymerisation rate will remain fluid and sticky for a shorter period of time, giving arthropods a shorter period to be trapped in the resin, resulting in a non-uniform distribution (Additional file 1: Fig. S1C) of arthropod inclusions. Arthropod attraction or repulsion to resin Attraction or repulsion toward resins may be physical or chemical in nature and are well documented for some arthropods [40]. From a physical point of view, the “water-imitating” reflection polarisation of resin has been proved for the presence of aquatic adult insects in amber [62]. Although more research is needed to understand how the light reflection of the resin may attract or repel other arthropods, an opaque and white surface (Figs. 1 and 6A, B, and C) may reflect less light than the transparent glue-like resin (Figs. 1 and 6D, E, and F), making Agathis resin a candidate for being less attractive. From a chemical point of view, it has been well documented in some resin-producing conifers that (—)- pinene, a constituent of stem oleoresin, increases in response to heightened insect activity, suggesting a defence mechanism [51]. Abundant — (α)- pinene has also been reported in araucariacean resins [63]. Conifer oleoresin is a complex compound comprising various monoterpenes, sesquiterpenes, and diterpene resin acids. The turpentine portion of the oleoresin includes over 30 monoterpenes and many sesquiterpenes, serving as a defence mechanism by being toxic to some pathogens and insects. Additionally, it aids in sealing plant wounds through the hardening action of diterpenes [51]. Also, the labdanes have been a subject of research due to their potential use as natural insecticides, showcasing antifeedant properties against some Coleoptera, Diptera, and Lepidoptera [64]. Labdanes are diterpenes featuring two aromatic rings in their structure, and are notably abundant in resins derived from the Araucariaceae [65, 66]. Volatile terpenoids, including labdanes, play then a dual role in defence by directly deterring herbivores and indirectly attracting their natural predators [67]. Moreover, these compounds also contribute to attracting pollinators for some gymnosperms such as cycads [68]. In the case of Hymenaea, both in Africa and South America, different resin compounds such as caryophyllene or α-Humulene are present to defend against various caterpillars and termites [40]. The resin of some angiosperm species also attracts insect pollinators or animals (birds and mammals) that can disperse their fruits [48]. The attractiveness or repulsiveness of the resin is an important taphonomic bias in the trapping of some groups of arthropods. However, determining whether Hymenaea can attract arthropods in more abundance than Agathis , or primarily some particular arthropod groups, requires experimental investigation. The role of yellow sticky and Malaise traps in studying Agathis resin Different orders of arthropods typically exhibit varying proportions in assemblages within amber, copal and Defaunation resins, with Diptera, Hymenoptera, and Coleoptera being the most abundant orders. The type of organism present and its abundance are contingent upon several taphonomic and ecological variables [1,3, 40], and these determined which part of the resiniferous forest is represented in the amber record [30]. In this context, we address two primary aspects of arthropod trapping: (1) whether Agathis resin traps arthropods in a similar way to yellow sticky traps, as observed with Hymenaea resin [30], and (2) whether the arthropod assemblage preserved in Agathis Defaunation resin is representative of the fauna in the same forest. From our actuotaphonomic studies in Madagascar, we know that the arthropod assemblage in the Hymenaea Defaunation resin is comparable to that in the yellow sticky traps placed on Hymenaea trunks. We also know that the assemblage differs notably from the arthropod fauna trapped in Malaise traps placed close to the trunks. This means that the arthropod assemblages trapped by Hymenaea resin represent mainly the fauna living in and around the trunk [30]. This pattern was reinforced by our second sampling in Sacaramy, Madagascar ([39] fig. 1), and shown in Fig. 4B, in which MDS also plots the arthropod assemblages in Defaunation resin from Hymenaea close to the arthropod assemblages in yellow sticky traps. On the contrary, MDS plots arthropod assemblages (at order level) in resin from Agathis far away from the arthropod assemblages in yellow sticky and Malaise traps in Agathis (Fig. 4). This stark contrast shows that Agathis resins exhibit a different trapping bias as an entomological trap like the yellow sticky traps. We found that arthropods preserved in amber and in Defaunation resin from Agathis and Agathis -like trees form distinct clusters at both the order and family levels (Fig. 5) (the latter focussed on dipteran families herein). In contrast, arthropods from yellow sticky and Malaise traps that were placed on and near Agathis trees cluster with those from amber, copal and Defaunation resin of Hymenaea origin. They also cluster with the arthropods from yellow sticky and Malaise traps on and near Hymenaea trees. This reinforces the idea that the resin of Hymenaea acts as an entomological trap ( i.e ., it has a trapping effect similar to yellow sticky traps), and that there is difference in the ways Agathis and Hymenaea resins trap arthropods. The arthropods trapped in Agathis Defaunation resin are mostly Arachnida or non-flying Hexapoda, except for one Thysanoptera and one Diptera remain. In contrast, the samples of Defaunation resin collected from Hymenaea tree trunks contain abundant Diptera (Additional file 2). However, as presented in the results, there was no a representative difference between flying and non-flying insects found in amber, copal, and Defaunation resin across the studied samples. Therefore, it is likely that this finding is due to the scarcity of material and needs more investigation. The number of Diptera specimens was very high in the yellow sticky traps placed on Agathis , this may be a reason why they plot close to the Malaise traps (Fig. 4C and Additional file 1: Fig. S5C), since Malaise traps are considered a successful method to collect flies [69]. Within the Diptera, the family Phoridae, overwhelmingly dominated the yellow sticky traps placed on Agathis , comprising nearly 90% of dipterans (Additional file 1: Fig. S2). As our collection took place in November and December, the humid months in New Caledonia, seasonality probably played an important role in determining abundance. Phoridae typically exhibit higher numbers during humid periods [70]. While other dipterans, namely Chloropidae, Sciaridae, and Cecidomyiidae, were also abundant in the yellow sticky traps placed at 1m height, their numbers are small in comparison to Phoridae. This may be a reason why they plot separately from Malaise traps (Fig. 4D and Additional file 1: Fig. S5D). Although not as abundant as in yellow sticky traps on Agathis , the family Phoridae was also abundant in yellow sticky traps placed on Hymenaea, and this family is also abundant in amber, particularly in Miocene ambers ( e.g ., [71]). Phoridae flies can be collected using a variety of traps [29, 72, 73]; however, yellow sticky traps seem to be the most effective one for collecting these flies [74, 75]. Small vertebrates, such as lizards, can also become trapped in yellow sticky traps, drawing in phorid flies that are attracted to decaying animal matter [41, 74, 76]. This phenomenon may also partly account for the high abundance of dipterans, particularly phorid flies, observed in New Caledonia in yellow sticky traps. Surprisingly, Phoridae is not present in Agathis Defaunation resin, and Diptera is notably underrepresented in that resin (Additional file 2). Resin production is affected by various factors, including temperature, humidity, growth, carbon assimilation, soil nutrients, or injuries [3, 31]. Therefore, it is not possible to establish a correlation between seasonality and the absence of phorid flies in the resin. Conclusion Given that Agathis and Hymenaea resins trap arthropods differently, a pattern inferred for extant and deep-time ecosystems, it is crucial to consider these different trapping biases (Fig. 1) when comparing fossil assemblages preserved in ambers from these two botanical sources. Several important factors influence the trapping of arthropods by Agathis resin. We consider that the most important factor is rapid drying, which results in a higher viscosity and the acquisition of a whitish patina on resin exuded from the trunk—even though Agathis resin is much more fluid than Hymenaea resin when it is originally exuded. Rapid drying prevents a large number of arthropods from being present as bioinclusions in the Agathis Defaunation resin, and it results in a statistically non-uniform spatial distribution of these. In contrast, Hymenaea resin has a higher viscosity when exuded, but it takes much longer to dry, and remains transparent; the slower drying allows arthropods to be abundant as bioinclusions in the resin, making their spatial distribution statistically more uniform. This leads us to conclude that Agathis resin does not act as an effective entomological trap for arthropods, unlike Hymenaea resin (Fig. 1). This suggests that the arthropods trapped in Agathis Defaunation resin (thanatocoenosis) (which eventually become amber - oryctocoenosis) do not reflect the fauna that lived in or surrounding the resin-producing trees (biocoenosis), unlike Hymenaea resin. This taphonomic pattern has critical implications for the interpretation of Cretaceous forest biocoenoses with an Agathis or Agathis -like origin. Although we discuss that Agathis resin is less effective at trapping arthropods than Hymenaea resin, we could not determine frequent ecological groups (arthropod guilds) trapped by Agathis resin using the small sample set that is available. Similarly, the fossil assemblages of arthropod bioinclusions in Eocene or Miocene Agathis ambers do not provide guild information due to the scarcity of deposits. A follow-up investigation (beyond collecting more Agathis resin with bioinclusions) could involve defining the criteria required to recognise guilds and categorising the inclusions found in Cretaceous amber, in order to determine the most prevalent types of arthropods in this amber type. The abundance of Cretaceous amber and Quaternary copal localities featuring numerous lumps but few bioinclusions, along with the non-uniform distribution of rare arthropod inclusions, can be partly attributed to substantial resin exudation from Agathis root systems. This exudation forms both large and small lumps in confined conditions. Comparable profuse resin production has not been observed from the root system of Hymenaea trees. Several unanswered questions still require further investigation, such as how resin attracts or repels some arthropods influencing the number of arthropods trapped, and the content of bioinclusions in the oryctocoenosis. Furthermore, this influence needs to be considered with respect to whether the trees involved were from the genera Agathis or Hymenaea, or from some close relatives. Further studies and more accurate taphonomic data are needed to identify the conditions in which arthropods were trapped in other ancient and modern resins from coniferous and leguminous trees, and to determine and how the oryctocoenosis originated. Methods Material We collected living arthropods using yellow sticky and Malaise traps, following the methodology outlined by Solórzano-Kraemer et al. [30]. These traps were installed on and close to Agathis lanceolata (Lindl. ex Sebert & Pancher) Warb., 1900 trees in Bon Secours forest, adjacent to the Rivière Bleue Provincial Park (New Caledonia), in 2016 (November – December, warm and rainy season), and on and close to Hymenaea verrucosa Gaertner, 1791 in Madagascar, Mananjary region (between Nosy Varika and Ambahy), in 2013 (September- October, warm and rather dry season), and Sacaramy (near to Diego Suarez), in 2015 (April – May, warm and rainy season) (Additional file 1: Fig. S6 and extended material and methods in Additional file 1). In total, we collected arthropods around four Agathis trees and eight Hymenaea trees (four Hymenaea trees per campaign). During each collection trip, we displayed 45 yellow sticky traps at three different heights on each tree for eight days, as well as four Malaise traps, one for each of four selected trees. We added to our analyses the data extracted from Solórzano-Kraemer et al. [29], who also collected arthropods with yellow sticky and Malaise traps in 2010, 2011 and 2012 on and close to Hymenaea courbaril Linné, 1753 in La Rinconada National Park in Mexico. The list of sampled arthropods can be seen in the Additional file 2. Throughout the manuscript we use the terms amber, copal, and Defaunation resin sensu Solórzano-Kraemer et al. [13]. In this system, amber is older than 2.58 Ma, copal is 2.58 Ma to 1760 AD (Anno Domini), and Defaunation resin is the resin produced after 1760 AD. We sampled Defaunation resins from eight Agathis lanceolata trees, and from 28 A. ovata (C. Moore ex Veill.) Warb., 1900 trees in New Caledonia. In Madagascar, resin was collected from 11 H. verrucosa trees in the Mananjary region in 2013 [30] and from 10 H. verrucosa trees in Sacaramy (for the precise location and map see [39], fig. 1) in 2015. All Defaunation resin samples were collected from tree trunks. From Mexico, no Defaunation resin was sampled from Hymenaea courbaril trees because resin exudates were virtually absent [29]. For the purposes of this paper, we do not distinguish between the different extant species of Agathis and Hymenaea involved in the collection work, or between the different ancient tree species proposed as the origin of the resin in the past (in the case of amber derived from Hymenaea , e.g . H. protera † Poinar, 1999, H. mexicana † Poinar and Brown, 2002, and H. allendis † Calvillo-Canadell et al., 2010). We use " Agathis " to refer to both living trees and fossil resins derived from Agathis trees. " Agathis -like" refers to fossil resins derived from ancient plants of the genus Agathis or only related to it. Cheirolepidiaceous ambers are also included as they are highly similar in chemistry to Agathis resins [8, 77]. Since the proposed botanical origin of Miocene amber is not questioned, we use Hymenaea to refer to both living trees and resins, as well as fossil resins derived from Hymenaea . We compared the arthropod assemblages obtained from yellow sticky and Malaise traps and those preserved within Defaunation resin from extant trees, with the arthropod assemblages preserved in amber from Late and Early Cretaceous and Middle Miocene from different localities around the world. All the amber, copal, and Defaunation resin collections included in the present study have been selected because they are unbiased and collected for scientific purposes; they have been collected in the field without prior selection of arthropod inclusions and/or whether the pieces/lumps containing arthropod inclusions or not. Searching for arthropod inclusions and preparing the pieces is a process that has been carried out in laboratory. With this purpose, we persuaded a detailed composition of the arthropod assemblages identified from Cretaceous amber from Spain and France, Eocene amber from Australian, Oligocene and Miocene amber from New Zealand, Miocene amber from the Dominican Republic and Mexico, copal and Defaunation resin from the Dominican Republic. Collections with the specification of the inclusions per gram of resin are mentioned in Table 1. Table 1 can be placed here. The references in the table are numbered from this point onwards. The term bioinclusion in amber, copal, and Defaunation resin includes all organismal remains that can be found in fossil resins. However, since arthropod inclusions are the only bioinclusions included in our analyses, we will use the term arthropod inclusions to refer to the bioinclusions we study here. The copal and Defaunation resin samples were polished and prepared in the same manner as amber [85, 86] to correctly identify the bioinclusions. However, for some lumps, it was only necessary to create a small viewing window to observe their contents. Imaging The photographs were performed with digital cameras Canon EOS 40D and Canon EOS 70D. Figures were performed using Adobe Photoshop software (version 25.4 www.adobe.com). Data processing The data used in this study were frequency data of taxa and experimental groups (amber, copal, and Defaunation resin, and yellow sticky and Malaise traps). Multivariate analyses were used to evaluate the different hypotheses of the study, namely, multidimensional scaling (MDS), and representation of the relationships for each experimental group in the form of a correlation heat-map or correlation network. Statistical analyses were performed using different R functions and libraries [87]. The BDbiost3 library for R [ 88, 89] was used for exploratory data analysis, and multidimensional scaling used functions LinesMDS() (see Additional file 1 for more detail on the statistical methods used [90, 91]). All data used for statistical work are available in Additional file 2. To estimate the degree of uniformity of arthropod inclusions in Defaunation resin from Agathis and Hymenaea , we estimated the probability density function (PDF) that a piece lacks arthropod inclusions given the mass of the piece (see Additional file 1 for a discussion of this methodology [92]). For this, we measured the mass of pieces with an error of 0.01g and we counted the number of arthropod inclusions in each piece (see Additional file 2). Then, we calculated the frequencies of pieces without arthropod inclusions and with a mass in intervals of 0.01g for the Defaunation resins from the Agathis and Hymenaea trees. These frequencies were associated with the conditional probability of finding a piece of mass m, given that it does not contain arthropod inclusions. Bayes' theorem was then used to obtain the conditional probability of not having arthropod inclusions given that the piece has mass m. Finally, we fit the resulting probabilities with power laws of the form by first obtaining the logarithm of the data, then using standard least squares algorithm with the fitting model log(a) - b log(m) to obtain the values of a and b for both collections. We used b as a measurement of the uniformity of arthropod inclusions. The exponent b measures the uniformity of arthropod inclusions, while the parameter a is just the estimated value of the PDF that a piece of resin has no arthropod inclusions within one gram of resin, and was only used to fit the data correctly. Abbreviations for Figure 4 : AA ES : Amber from Ariño, Spain; AAFR : Amber from Archingeay-Les Nouillers, France, mentioned in Perrichot et al. [21]; AAIFR : Amber Aix island, France; AAPES : Amber from Arroyo de la Pascueta, Spain; ABFR : Amber La Buzinie, France; ACFR : Amber Cadeuil, France; ADCO : Amber Doumanga, Congo; ADOG.P : Dominican amber collection from the private collection mentioned in Poinar [93]; ADOJ.C : Dominican amber from the Jorge Caridad private collection; AFFR : Amber Fouras, France; AFTFR : Amber Fourtou, France; AHES : Amber from La Hoya, Spain; AMX : Mexican amber collections mentioned in Solórzano-Kraemer et al. [29]; APES : Amber form Peñacerrada I, Spain; ARFR : Amber Les Renardières, France; ASES : Amber from El Soplao, Spain; ASJES : Amber from San Just, Spain; ASFR : Amber Salignac, France; CDO : Copal collected in 2019 in Cotuí, Dominican Republic; CTZ : Copal from Tanzania; MMG : Malaise trap installed close to Hymenaea in 2013 in Madagascar; MMX : Malaise trap installed close to Hymenaea since 2010 to 2012 in Mexico; MNC : Malaise trap installed close to Agathis in 2016 in New Caledonia; RMG1 : Defaunation resin collected from Hymenaea tree trunks in 2013 in Madagascar; RMG2 : Defaunation resin collected from Hymenaea tree trunks in 2015 in Madagascar; RNC : Defaunation resin collected from Agathis tree trunks in 2016 in New Caledonia; ST0MG , ST1MG , ST2MG : Yellow sticky traps placed at 0, 1 and 2 meters on Hymenaea tree trunks in Madagascar, respectively; ST0NC , ST1NC , ST2NC : Yellow sticky traps placed at 0, 1 and 2 meters in 2016 on Agathis tree trunks in New Caledonia, respectively; STTMG : Total yellow sticky traps placed around Hymenaea in 2013 in Madagascar; STTMX : Total yellow sticky traps placed around Hymenaea tree trunks in 2012 in Mexico; STTNC : Total yellow sticky traps placed around Agathis tree trunks in 2016 in New Caledonia. Declarations Acknowledgements We thank the family Caridad, owners of the Museo Mundo del Ámbar in Santo Domingo, S.B. Brower, F.A. Aquel Fernández, and Y.H. Shih (Dominican Republic) for their invaluable support, assistance during the scientific fieldwork, and donation of amber and copal/Defaunation resin pieces. Special thanks are given to R. Ravelomanana, M. Asensi, M. Madiomanana, and J. Andrianabo (Madagascar) for their dedicated assistance during fieldwork. Gratitude is expressed to Dr T. Rakotondrazafy, Director of the Départ. de Paléontologie et Anthropologie Biologique, and Dr E.M. Randrianarisoa, Director of the Départ. d’Entomologie, both at the Université d’Antananarivo (Madagascar), for their valuable help and advice in navigating administrative arrangements. The authors wish to acknowledge the contribution of the team at the Malagasy Institute for the Conservation of Tropical Environments (ICTE/MICET) for their support in the administrative development of the fieldwork in Madagascar. Thanks also go to J. Manauté and J. Delafenêtre from Parc Provincial de la Rivière Bleue, New Caledonia, for their support and assistance during fieldwork. The Direction de l’Environnement (DENV) Province Sud from Nouvelle Calédonie is acknowledged for granting the necessary fieldwork permits. Appreciation is extended to R. Kunz of the Senckenberg Research Institute (SMF) for his efforts in sorting, preparing and cataloguing the resin and copal collection deposited at the SMF and for the photos in the Figure 6H and I. Further gratitude is directed toward R. López del Valle (Spain) for their contribution to sorting, preparing, and cataloguing the Spanish amber. Thanks are due to Eduardo Espílez from Fundación Conjunto Paleontológico de Teruel-Dinópolis for cataloguing and curation of the Cretaceous Spanish amber from Teruel, and the director of that institution Dr Alberto Cobos. We would like to thank the three anonymous reviewers for their valuable feedback and corrections, which helped to improve the manuscript. We would like to extend our gratitude to José Antonio Peñas for his artistic illustration of Fig. 1. Consent for publication Authors agree to publication. Funding This work was supported by the Spanish Ministerio de Ciencia, Innovación y Universidades scientific projects CGL2017-84419/ AEI/FEDER, UE, and PID2022-137316NB, funded by MICIU/AEI/10.13039/501100011033 and by ERDF/EU; by DEGAPA-UNAM through the project PAPIIT IN113923, by the programme RYC2022-037026-I, funded by AEI/10.13039/ 501100011033 and the FSE+; by the Consejería de Industria, Turismo, Innovación, Transporte y Comercio of the Gobierno de Cantabria through the semi-public enterprise EL SOPLAO S.L. [research agreement #20963 with Universitat de Barcelona and research contract Ref. VAPC 20225428 to Instituto Geológico y Minero de España – Consejo Superior de Investigaciones Científicas, both 2022–2025]; the German VolkswagenStiftung (Project N. 90946), and the DFG project 457837041 (SO 894/6-1). Data availability All the data needed to evaluate the conclusions of the paper are available in the paper and in the supplementary information files. The amber from “El Valle – 7 Cañadas” and San Rafael, Dominican Republic have been acquired directly in the mine by MMS-K, XD and EP. The copal/Defaunation resin from Cotuí, Dominican Republic, have been acquired by Y.H. Shih. These amber and copal/Defaunation resin will be housed in the Museo Nacional de Historia Natural ‘Prof. Eugenio de Jesús Marcano’ in Santo Domingo, Dominican Republic. Correspondence for material related to this paper can be sent to Mónica M. Solórzano-Kraemer ( [email protected] ), Enrique Peñalver ( [email protected] ), and Xavier Delclòs ( [email protected] ). Authors’ contributions M.M.S-K., E.P. and X.D. conceived the idea, designed the methodology, analysed the data and drafted the manuscript. M.M.S-K., designed the first draft. A.M-G. and A.S.K. performed the statistical analysis. M.M.S-K., E.P., X.D., M.C.M.H., D.P., A.A., V.P. and M.P. identified the specimens, and provided the list of specimens, M.M.S-K., E.P., X.D., E.B. and R.G. carried out the field work. M.M.S.-K., E.B., E.P. and X.D. acquired and managed project funding. All authors contributed critically to the drafts and gave final approval of the manuscript. Competing interests The authors declare no competing interests. Ethics approval and consent to participate Not applicable. 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A review of amber and copal occurrences in Africa and their paleontological significance. Bull. Soc. geol. Fr. 2020;191(17):1–11. Corral JC, López del Valle R, Alonso J. El ámbar cretácico de Álava (Cuenca Vasco-Cantábrica, Norte de España). Su colecta y preparación. Est Mus Cienc Nat de Álava 1999;14 Núm. Espec. 2: 7–21. Sadowski EM, Schmidt AR, Seyfullah LJ, Solórzano-Kraemer MM, Neumann C, Perrichot V, et al. Conservation, preparation and imaging of diverse ambers and their inclusions. Earth-Sci Rev. 2021;220:103653. https://doi.org/10.1016/j.earscirev.2021.103653 R Core Team. R: A language and environment for statistical computing. Vienna, Austria: R Foundation for Statistical Computing; 2024. https://www.R-project.org/ Monleón-Getino A, Rodríguez-Casado C, Mendez-Viera J. How to calculate number of samples in the design of pre/pro-biotics studies (metagenomic studies). III WorkShop Insa-UB 2017; 1–2. doi:10.13140/RG.2.2.27611.67367 Monleón-Getino A. T. Library for R BDSBIOST3: Machine Learning and Advanced Statistical Methods for Omic categorical analysis and others. 2020. https://github.com/amonleong/BDSbiost3 Hout MC, Papesh MH, Goldinger SD. Multidimensional scaling. Wiley Interdiscip Rev Cogn Sci. 2013;4(1):93–103. doi:10.1002/wcs.1203. Rodríguez-Casado C, Monleón-Getino T, Alcolea M. A priori groups based on Bhattacharyya distance and partitioning around medoids algorithm (PAM) with applications to metagenomics. IOSR J Math. 2017;13(3):24–32. Ross SM. A first course in probability. 5th ed. USA: Pearson; 1997. Poinar GO, Poinar R. The amber forest: a reconstruction of a vanished world. New Jersey: Princeton University Press; 1999 Tables Table 1. Number of arthropod inclusions per gram in amber, copal, or Defaunation resin that are reported in the literature and own data. The amber, copal, and Defaunation resin (collected directly from the trees) from the different areas were not pre-selected in terms of containing or not containing arthropod inclusions. *The table includes collections that are unbiased in terms of arthropods per gram; unbiased collections only in terms of no pre-selection of arthropod species are not included here.** Stilwell et al. [35] do not specify a source for this amber, but its age and provenance suggest Agathis sp. Locality/Area of collection Age of resin Resiniferous tree Weight / Pieces N. of arthropod inclusions Citation Mananjary region (between Nosy Varika and Ambahy), Madagascar Resin collected in 2013 Hymenaea verrucosa (Caesalpiniaceae) 800.5 grams 1743 Solórzano-Kraemer et al. [30] Sacaramy (close to Antsiranana, Diego Suarez), Madagascar Resin collected in 2015 Hymenaea verrucosa (Caesalpiniaceae) 1500 grams 2141 Own data Col de Yaté South Province (Gramseat South), New Caledonia Resin collected in 2016 Agathis ovata (Araucariaceae) 1627.1 grams 40 Own data Bon Secours (close to Rivière Bleue Provincial Park, South Province, Gramseat South), New Caledonia Resin collected in 2016 Agathis lanceolata (Araucariaceae) 991.6 grams 8 Own data Copal / Defaunation resin from Cotuí, Dominican Republic Unknown Hymenaea courbaril (Caesalpiniaceae) 1875.2 grams 319 Own data Amber from Totolapa, Chiapas, Mexico. early Miocene † Hymenaea mexicana Poinar and Brown, 2002 (Caesalpiniaceae) 2000 grams 107 Solórzano-Kraemer et al. [29] Amber from El Valle 7 Cañadas, Dominican Republic early Miocene † Hymenaea protera Poinar, 1991 (Caesalpiniaceae) 1678.8 grams 270 Own data Amber from San Rafael, Dominican Republic early Miocene † Hymenaea protera (Caesalpiniaceae) 523.5 grams 140 Own data Amber from Southland region of the South Island, and Otago, New Zealand late Oligocene and early Miocene Agathis sp.(Araucariaceae) the exact amount is unknown, estimation: 1000 to 1500 grams 78 Schmidt et al. [45] (Alexander Schmidt, pers. comm., February 2023) Amber from Anglesea Coal Measures (ACM), Australia early Eocene * Agathis sp ca. 2000 grams 47 Stilwell et al. [35], own data 2025 Amber from Macquarie Harbour Formation (MHF), Australia early Eocene * Agathis sp ca. 1500 grams 2 Stilwell et al. [35], own data 2025 Amber from Fourtou, France middle Cenomanian † Agathoxylon sp. (Araucariaceae) or †Cheirolepidiaceae ca. 2000 grams 40 Girard et al. [78], own data 2025 Amber from Fouras/Bois Vert, France early Cenomanian † Agathoxylon gardoniense (Araucariaceae) and †Cheirolepidiaceae ca. 3000 grams 113 Néraudeau et al. [79], Perrichot et al. [21], own data 2025 Amber from Ile d’Aix, France early Cenomanian † Agathoxylon gardoniense (Araucariaceae) and †Cheirolepidiaceae ca. 500 grams 6 Néraudeau et al. [80], own data 2025 Amber from La Buzinie, France early Cenomanian † Agathoxylon gardoniense (Araucariaceae) and †Cheirolepidiaceae ca. 6000 grams 149 Perrichot et al. [21], own data 2025 Amber from Salignac, France early Cenomanian Araucariaceae ca. 400 grams 27 Perrichot et al. [21], own data 2025 Amber from Archingeay-Les Nouillers, France late Albian † Agathoxylon gardoniense (Araucariaceae) and †Cheirolepidiaceae 35000 to 40000 grams 1330 Perrichot et al. [21], own data 2025 Amber from Les Renardières, France late Albian † Agathoxylon gardoniense (Araucariaceae) and †Cheirolepidiaceae 300 grams 4 Perrichot et al. [21], own data 2025 Amber from Cadeuil, France late Albian † Agathoxylon gardoniense (Araucariaceae) and †Cheirolepidiaceae ca. 8000 grams 98 Néraudeau et al. [81], own data 2025 Amber from Peñacerrada, Álava, Spain late Albian (Early Cretaceous) Agathis -like (Araucariaceae) (Chaler and Gramsimalt [82]) 139500 grams 3346 Own data Amber from San Just, Teruel, Spain late Albian (Early Cretaceous) Agathis -like (Araucariaceae) 12900 grams 387 Own data Amber from La Hoya, Castellón, Spain early Cenomanian (Early Cretaceous) Agathis -like (Araucariaceae) 5500 grams 11 Own data Amber from El Soplao, Cantabria, Spain middle Albian (Early Cretaceous) Frenelopsis sp. (†Cheirolepidiaceae) and other possible Cupressaceae (Menor-Salván et al. [77]) 19937 grams 1600 Own data Amber from Arroyo de la Pascueta, Teruel, Spain late Albian (Early Cretaceous) Agathis -like (Araucariaceae) 7000 grams 14 Own data Amber from La Rodada, La Manjoya, Spain late Albian (Early Cretaceous) Agathis -like (Araucariaceae) 500 grams 2 Peñalver et al. [83] Amber from Ariño, Teruel, Spain early Albian (Early Cretaceous) Agathis -like (Araucariaceae) (Álvarez-Parra et al. [46]) 1128 grams 100 Own data Amber from Doumanga, Congo middle Aptian † Agathoxylon sp. (Araucariaceae) or †Cheirolepidiaceae 2550 grams 47 Bouju & Perrichot [84], own data 2025 Additional Declarations No competing interests reported. Supplementary Files Additionalfile1SupplementaryInformationVBMCBiologyFINALcorrectedcleanFINAL.docx Additionalfile2ArthropodlistVBMCBiologyFINAL.xlsx Additionalfile3inclusionspergramVBMCBiologyFINAL.xlsx Cite Share Download PDF Status: Published Journal Publication published 06 Nov, 2025 Read the published version in BMC Biology → Version 1 posted Editorial decision: Accepted 22 Oct, 2025 Submission checks completed at journal 09 Oct, 2025 First submitted to journal 08 Oct, 2025 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. 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Dark green shading indicates the current geographic distribution of \u003cem\u003eAgathis\u003c/em\u003e, while light green shading shows that of \u003cem\u003eHymenaea\u003c/em\u003e. The relative whiteness of the resin reflects the speed of hardness in \u003cem\u003eAgathis\u003c/em\u003e. Amber, copal, or Defaunation resins from most of the localities represented here are included in this study (see Table 1 and Additional file 1). Large lumps of resin are produced only in the roots of the \u003cem\u003eAgathis\u003c/em\u003e. The schematic also illustrates the effectiveness of each resin type as an entomological trap for arthropods.\u003c/p\u003e","description":"","filename":"Fig1graphicrepresentationoftheresults.png","url":"https://assets-eu.researchsquare.com/files/rs-6999659/v1/052948fb1971231a3f67dc56.png"},{"id":94386253,"identity":"56ef88db-9ce7-4827-b599-2f6a5af7ffed","added_by":"auto","created_at":"2025-10-27 13:49:32","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":6424638,"visible":true,"origin":"","legend":"\u003cp\u003eScatter plot showing the number of arthropod inclusions as a function of resin mass (in grams) for \u003cem\u003eAgathis\u003c/em\u003e and \u003cem\u003eAgathis\u003c/em\u003e-like samples (red-organge) and \u003cem\u003eHymenaea\u003c/em\u003e samples (blue). The inset displays the same data in log–log scale. Continuous lines represent fitted power-law functions, with exponents constrained between ⅔ and 1. Shaded bands around the fits indicate the standard error of the estimates. The dataset used to generate this figure is available in Additional file 3. Spanish, French, Australian, New Zealand, and New Caledonian resin exudates were produced by conifers; Dominican, Mexican, and Malagasy resin exudates were produced by angiosperms\u003c/p\u003e","description":"","filename":"Fig2Scatterplot.png","url":"https://assets-eu.researchsquare.com/files/rs-6999659/v1/d011ba577c137b874cde348f.png"},{"id":94386655,"identity":"1655ccc7-eecb-4174-bdd0-a1cbb59a35ec","added_by":"auto","created_at":"2025-10-27 13:49:48","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":4510764,"visible":true,"origin":"","legend":"\u003cp\u003eLog-log plot of the probability distribution function (PDF).\u003cstrong\u003e \u003c/strong\u003ePDF of finding a piece of Defaunation resin without arthropod inclusions given that the piece has a mass m [resin (grams)] for Defaunation resins from \u003cem\u003eAgathis\u003c/em\u003e (New Caledonia) and \u003cem\u003eHymenaea\u003c/em\u003e (Madagascar) trees. Both distributions follow a power law, with exponents of b = -1.97 for \u003cem\u003eAgathis\u003c/em\u003e Defaunation resin and b = -3.34 for \u003cem\u003eHymenaea\u003c/em\u003e Defaunation resin. The exponent b indicates the uniformity of the distribution, with more negative values approaching a uniform system (see Additional file 1 for further explanation). Note that in the case of the \u003cem\u003eHymenaea\u003c/em\u003eDefaunation resin, with collections in which the smaller pieces only weight 0.01 grams, a change in the behaviour of the curve appears at around 0.5 grams. This change in trend is likely due to human bias during collection. For this reason, we did not use the data corresponding to pieces smaller than 0.5 grams to obtain the exponent b\u003c/p\u003e","description":"","filename":"Fig3Loglogplot.png","url":"https://assets-eu.researchsquare.com/files/rs-6999659/v1/52ee7f33e80068bc1f67ec11.png"},{"id":94386631,"identity":"acc9d36f-136f-4011-80be-e7ea679229e7","added_by":"auto","created_at":"2025-10-27 13:49:46","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":1684157,"visible":true,"origin":"","legend":"\u003cp\u003eMultidimensional scaling (MDS) using Bhattacharyya distance for arthropod orders (A-C) and Diptera families (D) trapped on the trunk and close to \u003cem\u003eAgathis\u003c/em\u003e and \u003cem\u003eHymenaea\u003c/em\u003e trees. \u003cstrong\u003eA\u003c/strong\u003eby the yellow sticky and Malaise traps and by Defaunation resin in an \u003cem\u003eAgathis\u003c/em\u003e forests in New Caledonia. \u003cstrong\u003eB\u003c/strong\u003e by the yellow sticky and Malaise traps and by Defaunation resin in an \u003cem\u003eHymeaea\u003c/em\u003eforests in Madagascar. \u003cstrong\u003eC\u003c/strong\u003e by the yellow sticky and Malaise traps in an \u003cem\u003eAgathis\u003c/em\u003eforest in New Caledonia and in an \u003cem\u003eHymenaea\u003c/em\u003eforests in Madagascar and Mexico. \u003cstrong\u003eD\u003c/strong\u003eby yellow sticky and Malaise traps in an \u003cem\u003eAgathis\u003c/em\u003eforest in New Caledonia and in an \u003cem\u003eHymenaea\u003c/em\u003eforests in Madagascar and Mexico. The MDS plot shows the proportion of variance explained by each component of the Bhattacharyya distance scaling for each axis. Red arrows: In A, arthropods trapped by the \u003cem\u003eAgathis\u003c/em\u003e Defaunation resin are far from the Malaise traps and yellow sticky. In B, arthropods trapped by the \u003cem\u003eHymenaea\u003c/em\u003e Defaunation resin are far from the Malaise traps. In C, arthropods trapped by the yellow sticky traps on \u003cem\u003eAgathis\u003c/em\u003e tree trunks are far from the other yellow sticky traps on \u003cem\u003eHymenaea\u003c/em\u003etree trunks. In D, Diptera trapped by the yellow sticky traps on \u003cem\u003eAgathis\u003c/em\u003e tree trunks are far from all other yellow sticky and Malaise traps whether they were on or close to \u003cem\u003eAgathis\u003c/em\u003e or \u003cem\u003eHymenaea\u003c/em\u003e. The prefixes ST and M stand for yellow sticky and Malaise traps respectively, and R for resin (R1 collected in 2013, and R2 collected in 2015). ST followed by a number represents the height in metres at which the yellow sticky trap was placed on the tree trunk. T represents the sum of arthropods trapped in sticky traps in one location. The suffixes NC, MG, and MX stand for New Caledonia, Madagascar, and Mexico respectively\u003c/p\u003e","description":"","filename":"Fig4MDS.png","url":"https://assets-eu.researchsquare.com/files/rs-6999659/v1/50a7f52228aea688446713d6.png"},{"id":94387340,"identity":"fe9b282b-cae5-42d7-a457-8359af311d64","added_by":"auto","created_at":"2025-10-27 13:50:14","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":229790,"visible":true,"origin":"","legend":"\u003cp\u003eDendrograms from Hierarchical Clustering of arthropods using 1-Spearman correlation at order and family levels for Diptera. \u003cstrong\u003eA\u003c/strong\u003e Arthropod specimens by orders in all collected samples of amber, copal and Defaunation resin as well as arthropod specimens trapped by the yellow sticky and Malaise traps. \u003cstrong\u003eB\u003c/strong\u003e Dipteran specimens by families in all the collected samples of amber, copal and Defaunation resin as well as dipteran specimens trapped by the yellow sticky and Malaise traps. To enhance interpretation, hierarchical clustering was applied to group similarly correlated variables, arranging them closer together, using 1-correlation distance and the complete linkage method. The meaning of the abbreviations is given in the Material and Methods section\u003c/p\u003e","description":"","filename":"Fig5clustering.png","url":"https://assets-eu.researchsquare.com/files/rs-6999659/v1/a73e5b6a8c37539b60251856.png"},{"id":94386447,"identity":"f2a0215c-28d9-4260-a7eb-00ee77ab5ac8","added_by":"auto","created_at":"2025-10-27 13:49:40","extension":"png","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":1644727,"visible":true,"origin":"","legend":"\u003cp\u003eResin (Defaunation resin) exuded by tree trunks and branches some with examples of trapped biological remains, principally arthropods and plants.\u003cstrong\u003e A\u003c/strong\u003e, \u003cstrong\u003eB\u003c/strong\u003e and \u003cstrong\u003eC\u003c/strong\u003e \u003cem\u003eAgathis\u003c/em\u003e \u003cem\u003eovata\u003c/em\u003e (C. Moore ex Veill.) Warb., 1900 in Col de Yaté, New Caledonia. \u003cstrong\u003eD\u003c/strong\u003e, \u003cstrong\u003eE\u003c/strong\u003e and \u003cstrong\u003eF\u003c/strong\u003e \u003cem\u003eHymenaea\u003c/em\u003e \u003cem\u003everrucosa\u003c/em\u003e Gaertner, 1791 in the Mananjary region, Madagascar. Note the surfaces of the \u003cem\u003eAgathis\u003c/em\u003e resin lumps with a whitish patina due to faster drying and hardening which prevent the presence of organismal inclusions (A, B, and C). \u003cem\u003eHymenaea\u003c/em\u003eresin, which generally is rich in arthropods and plant inclusions (as more clearly shows the photographs H and I), remains sticky for a long time and does not show a such whitish patina (D, E, and F), even after complete hardening/drying. \u003cstrong\u003eG\u003c/strong\u003e trapped arthropods partially embedded in \u003cem\u003eHymenaea\u003c/em\u003eresin in the Mananjary region, Madagascar. \u003cstrong\u003eH\u003c/strong\u003e and \u003cstrong\u003eI\u003c/strong\u003e trapped arthropods totally embedded in \u003cem\u003eHymenaea\u003c/em\u003e resin from the Mananjary region, Madagascar. Scale size in H and I is 10 mm\u003c/p\u003e","description":"","filename":"Fig6ResintypesAgathisHymenaea.png","url":"https://assets-eu.researchsquare.com/files/rs-6999659/v1/4aa63e333aa796550c0e000d.png"},{"id":95580465,"identity":"d64a6f37-8e29-4708-ab05-79183f470421","added_by":"auto","created_at":"2025-11-10 20:02:38","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":24475657,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-6999659/v1/0a986518-53d5-447b-9efb-91946e9e962e.pdf"},{"id":94386276,"identity":"795a62d3-a351-45b8-8243-a7036fa8530b","added_by":"auto","created_at":"2025-10-27 13:49:32","extension":"docx","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":3373094,"visible":true,"origin":"","legend":"","description":"","filename":"Additionalfile1SupplementaryInformationVBMCBiologyFINALcorrectedcleanFINAL.docx","url":"https://assets-eu.researchsquare.com/files/rs-6999659/v1/0d6b78f237150a0e68839676.docx"},{"id":94387208,"identity":"afa6e5c0-ed5a-48b8-ad6e-53b17de588b9","added_by":"auto","created_at":"2025-10-27 13:50:08","extension":"xlsx","order_by":2,"title":"","display":"","copyAsset":false,"role":"supplement","size":49789,"visible":true,"origin":"","legend":"","description":"","filename":"Additionalfile2ArthropodlistVBMCBiologyFINAL.xlsx","url":"https://assets-eu.researchsquare.com/files/rs-6999659/v1/a3cb6ce5643c7aa7b4b494c8.xlsx"},{"id":94386421,"identity":"1f62134a-9740-41aa-a77a-f1f5fd69cdfa","added_by":"auto","created_at":"2025-10-27 13:49:38","extension":"xlsx","order_by":3,"title":"","display":"","copyAsset":false,"role":"supplement","size":74951,"visible":true,"origin":"","legend":"","description":"","filename":"Additionalfile3inclusionspergramVBMCBiologyFINAL.xlsx","url":"https://assets-eu.researchsquare.com/files/rs-6999659/v1/b1c3d8b68481a5c0c388f38e.xlsx"}],"financialInterests":"No competing interests reported.","formattedTitle":"Agathis vs. Hymenaea – trapping biases to interpret arthropod assemblages in ambers","fulltext":[{"header":"Background","content":"\u003cp\u003eAmber is a fossil plant resin, that sometimes preserves inorganic inclusions such as water or soil particles, and a high diversity of bioinclusions, such as phloem sap, plant remains, microorganisms, invertebrates (with arthropods being the most abundant) and vertebrate remains, providing a unique window into\u0026nbsp;biocoenoses in\u0026nbsp;ancient forested ecosystems [1–4]. In the Cretaceous period, conifers were globally the primary contributors to sedimentary deposits of resin (today amber) [5]. Several families have been proposed as the producers of large quantities of resin at that time, namely Araucariaceae, Cupressaceae, Pinaceae,\u0026nbsp;Podocarpaceae\u0026nbsp;and the extinct\u0026nbsp;Cheirolepidiaceae [6–9]. Moving to the Eocene epoch, amber deposits were derived from conifers and angiosperms. For example, Eocene Baltic amber originated from a conifer tree of the family Pinaceae and/or Cupressales: Sciadopityaceae [10, 11], while Cambay (India) amber was linked to the angiospermous Dipterocarpaceae [12]. Conversely, the majority of Miocene ambers, copals, and Defaunation resins (\u003cem\u003esensu\u003c/em\u003e Solórzano-Kraemer et al. [13]) were derived from angiosperms, predominantly of the families Fabaceae and Dipterocarpaceae [13, 14].\u003c/p\u003e\n\u003cp\u003eThe Cretaceous, Paleogene and Neogene periods are the most prolific in terms of described amber deposits [5, 13]. However, a difference has been noted in unbiased collections between the amber that originated from conifers and that from angiosperms. Of the approximately 500 Barremian amber localities known in Lebanon, only 38 contain arthropod inclusions [15, 16]. Similarly, of the more than 140 Albian amber localities in Spain, only 11 contain arthropod inclusions [17, 18]; of these, four are poor and contain only one or two arthropod inclusions. Another example is the Albian\u003cem\u003e―\u003c/em\u003eCenomanian French amber, with 60 reported localities, of which 14 contain arthropod inclusions, but only one, Archingeay-Les Nouillers, was reported as highly fossiliferous [19–23]. Cretaceous amber from Southern America seems to exhibit a similar circumstance, as arthropod inclusions have remained elusive despite many years of intensive searching [24–26]. Only 21 terrestrial arthropods in Ecuadorian Albian amber are known until now from South America [27]. It is important to consider that many Cretaceous amber deposits mentioned in the literature contain only an anecdotal amber record. Deposits with significant amber quantities are scarce [5], and researchers primarily focus on amber-rich deposits when searching for arthropod inclusions.\u003c/p\u003e\n\u003cp\u003eOn the contrary, Cenozoic amber localities (from the Paleogene and Neogene) appear less abundant than in the Cretaceous, but nearly all contain arthropod inclusions [13,28]. However, the inclusion density, i.e. the number of specimens per volume or mass of inspected amber, has never been studied before. These observations raise question on whether the difference in arthropod inclusions is due to a different distribution of fauna in the ecosystem or a different trapping bias of the resins.\u003c/p\u003e\n\u003cp\u003eResin has been defined as an entomological trap that works similarly to commercial yellow sticky traps [29, 30]. The fauna living in and around the resin-producing trees of \u003cem\u003eHymenaea\u0026nbsp;\u003c/em\u003eLinnaeus, 1753 has been described as having a greater chance of being trapped and preserved in the resin (the so-called thanatocoenosis or death assemblage), than the fauna living in surrounding areas of the forest [30]. Some resins often contain inclusions that are closely related to the habitats provided by resiniferous trees. Diptera is an order that contains a high number of inclusions in amber. Most of these insects are fungivores, carnivorous, necrophagous, or hematophagous, which explains why they are commonly found as amber inclusions [30]. \u003cem\u003eAgathis\u003c/em\u003e Salisbury, 1807 (Araucariaceae) and \u003cem\u003eHymenaea\u0026nbsp;\u003c/em\u003e(Fabaceae) genera contain resin-producing tree species serving as pivotal models for actuotaphonomic investigations in this respect [29–32]. The genus \u003cem\u003eAgathis\u0026nbsp;\u003c/em\u003eis primarily distributed today in the Southern Hemisphere\u003cem\u003e,\u003c/em\u003e growing in tropical environments across the Malay Archipelago (Malesia), the islands of the South-West Pacific (Melanesia), northern New Zealand, and South Queensland in Australia [33]. \u003cem\u003eAgathis\u003c/em\u003e or \u003cem\u003eAgathis\u003c/em\u003e-like trees have been postulated to be the source of certain Cretaceous and Cenozoic ambers from Lebanon (Barremian), Spain (Albian), France (Albian-Cenomanian), Myanmar (Cenomanian), Australia (Turonian–Campanian), and New Zealand (Oligocene and Miocene), while there is certainty that \u003cem\u003eAgathis\u003c/em\u003e was or is involved in the origin of the copals and Defaunation resins from New Zealand and New Caledonia [3, 13, 34, 35]. \u003cem\u003eHymenaea\u0026nbsp;\u003c/em\u003eis a tropical and subtropical resin-producing tree originating in East Africa during the early Miocene, mainly distributed throughout central and South America, and East Africa (including Kenya, Tanzania, Mozambique, Comoros, Madagascar, Mauritius and Reunion Island) [36–39]. The genus \u003cem\u003eHymenaea\u0026nbsp;\u003c/em\u003ehas been identified as the source of the ambers from Ethiopia, Mexico, Dominican Republic (all Miocene in age), Pleistocene and Holocene copals, and Defaunation resins from East Africa, and Central and South America [13, 39, 40].\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eUnderstanding why many amber deposits are poor or devoid in arthropod inclusions, and why this holds true for Cretaceous deposits more than for Paleogene and Neogene ones, would contribute to a better interpretation of oryctocoenoses (fossil assemblages)\u0026nbsp;based on amber records. We have thus carried out a comparative actuotaphonomic study based on \u003cem\u003eAgathis\u003c/em\u003e trees from New Caledonia and \u003cem\u003eHymenaea\u0026nbsp;\u003c/em\u003etrees from Madagascar. We followed the same experimental protocol as in a previous study based on \u003cem\u003eHymenaea\u003c/em\u003e from Madagascar [30] in order to compare the results. Our aim was to quantify, using statistical analysis, the differences in the intensity of arthropod trapping between the resin exuded by two different resin-producing trees (\"gymnosperms\" exclusively conifers vs. angiosperms) in their natural environments, with a view to applying the conclusions to the reconstruction of deep-time environments based on fossil assemblages preserved in amber.\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003e\u003cstrong\u003eTrapping patterns of arthropods in ambers, copals and Defaunation resins from \u003cem\u003eAgathis\u003c/em\u003e, \u003cem\u003eAgathis\u003c/em\u003e-like, and \u003cem\u003eHymenaea\u0026nbsp;\u003c/em\u003etrees\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFig. 1 can be placed here\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eIn the Defaunation resin obtained from \u003cem\u003eAgathis\u0026nbsp;\u003c/em\u003ein New Caledonia (Additional file 1: Fig. S1), a total of 48 arthropod inclusions were found in 2,618.7 grams of resin (Table 1), mostly Acari, Pseudoscorpiones, Collembola and non-flying Hymenoptera, namely Formicidae, but also a Thysanoptera and a Diptera remain. This scarce number of arthropods in \u003cem\u003eAgathis\u003c/em\u003e Defaunation resin was unexpected, particularly considering the significant number of arthropod inclusions (~4,000) found in 2,300 grams of Malagasy Defaunation resin from \u003cem\u003eHymenaea\u003c/em\u003e (Table 1, see Additional file 2 for a detailed list of arthropod inclusions). We observed a visible divergence in arthropod trapping efficiency (Fig. 1). Here, efficiency refers to two things: First, it refers to the increased trapping of arthropods and other organisms by both ancient and modern resins. Second, it refers to the recording of a more complete (varied) assemblage that better reflects the communities that inhabited these ancient and modern forests. We also observed a visible divergence in arthropod trapping patterns, represented in Fig. 2, between \u003cem\u003eAgathis\u003c/em\u003e and \u003cem\u003eAgathis\u003c/em\u003e-like, and \u003cem\u003eHymenaea\u003c/em\u003e samples (including ambers and copal from both types of trees). When comparing arthropod counts with resin mass, two different trends emerge: With the increase in resin mass, the pattern of \u003cem\u003eAgathis\u003c/em\u003e and \u003cem\u003eAgathis\u003c/em\u003e-like samples show a slow, near-flat increase. Meanwhile, \u003cem\u003eHymenaea\u003c/em\u003e samples show a sharp increase, indicating markedly higher trapping efficiency.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFig. 2 can be placed here\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe different arthropod trapping patterns observed in the \u003cem\u003eHymenaea\u003c/em\u003e and \u003cem\u003eAgathis\u003c/em\u003e Defaunation resins are revealed not only by the number of arthropod inclusions per mass of resin (Fig. 2), but also by the probability that a collected Defaunation resin piece/lump with a certain mass does not have any inclusions. The thanatocoenosis (death assemblages) varies greatly between that of \u003cem\u003eAgathis\u003c/em\u003e Defaunation resin and that of \u003cem\u003eHymenaea\u003c/em\u003e Defaunation resin, which will considerably influence the interpretation of the resulting oryctocoenosis.\u0026nbsp;The probability density function (PDF) of resin pieces lacking arthropod inclusions was analysed in relation to mass for \u003cem\u003eHymenaea\u003c/em\u003e (Madagascar) and \u003cem\u003eAgathis\u003c/em\u003e (New Caledonia) Defaunation resins\u0026nbsp;(Fig. 3). The distributions for both types of resin followed a power-law trend, with exponents of b = -1.97 and b = -3.34 for \u003cem\u003eAgathis\u003c/em\u003e and \u003cem\u003eHymenaea\u003c/em\u003e, respectively. The exponent b is a measure of distribution uniformity: values closer to zero indicate greater variability, while more negative values suggest a system approaching uniformity\u0026nbsp;(an explanation of PDF and the degree of uniformity is presented in the Additional file 1). For \u003cem\u003eHymenaea\u003c/em\u003e, the probability decreases rapidly as the mass increases; for \u003cem\u003eAgathis\u003c/em\u003e, however, the decrease is gradual. This reflects the fact that large \u003cem\u003eAgathis\u003c/em\u003e pieces lack arthropod inclusions. The rate at which the probability decreases reflects the distribution of arthropod inclusions. A uniform distribution leads to an exponential decrease corresponding to an infinite exponent b, whereas a distribution in which all inclusions are concentrated in a single location would have an exponent of b = 0. Thus, the value of b serves as an indicator of the uniformity of the distribution of arthropod inclusions in amber. If the only difference were a lower arthropod density around \u003cem\u003eAgathis\u003c/em\u003e and both resins trapped them equally, the lines would have the same shape but offset from each other and they would appear parallel. Therefore, the different values of b for each collection of pieces of Defaunation resin show that \u003cem\u003eHymenaea\u003c/em\u003e resin traps arthropods more efficiently and more uniformly than \u003cem\u003eAgathis\u003c/em\u003e resin (see also Additional file 1: Fig. S1 and extended material and methods in Additional file 1). In other words, the characteristics of the thanatocoenosis are very different for each type of resin under investigation here.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFig. 3 can be placed here\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eArthropod trapping patterns including yellow sticky and Malaise traps\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe significant difference in arthropod trapping patterns observed in the Defaunation resins raises questions about the trapping efficiency of other entomological traps we used, which were placed: i) on the trunk and ii) close to the same tree species. These include yellow sticky traps, which resemble the sticky resin, and Malaise traps – both of which are used for arthropod collection and actuotaphonomic studies [29, 30, 41, 42]. Therefore, to better understand the trapping patterns and to assess whether \u003cem\u003eAgathis\u003c/em\u003e tree resin traps arthropods in a similar way to yellow sticky traps, we analysed their arthropod assemblages using multidimensional scaling (MDS) with Bhattacharyya distance, in order to visualise the relationships between the taxa based on their frequency data. An important result is that the arthropods (at the order level) in the \u003cem\u003eAgathis\u003c/em\u003e Defaunation resin, collected from the tree trunks in New Caledonia, plots far from the arthropods (at the order level) collected in both the yellow sticky and Malaise traps placed on the trunk and close to the \u003cem\u003eAgathis\u003c/em\u003e trees, respectively (Fig. 4A) (in the Additional file 2 we present the arthropod list). The arthropods (at order level) trapped in the yellow sticky traps in New Caledonia plotted far away from the arthropods trapped in the Malaise traps, but also far from the yellow sticky and Malaise traps from other sampling places, such as the \u003cem\u003eHymenaea\u003c/em\u003e forests in Madagascar and Mexico (Fig. 4C), where the \u003cem\u003eHymenaea\u003c/em\u003e trees were also sampled [29, 30]. In contrast, the samples from \u003cem\u003eHymenaea\u003c/em\u003e trees in Madagascar, analysed using the same method, plots the arthropods (at the order level) in the \u003cem\u003eHymenaea\u003c/em\u003e Defaunation resin from the tree trunks close to the arthropods collected in the yellow sticky traps (Fig. 4B).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFig. 4 can be placed here\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eFamilies in Diptera deserve a special analysis below the order level, attending to their high abundance in the collected material and in general in amber [43]. In the yellow sticky traps placed on the trunkof \u003cem\u003eAgathis,\u003c/em\u003e Diptera made up more than 60% of the total. Within the Diptera, the family Phoridae comprised nearly 90% (Additional file 1: Fig. S2). At family level within Diptera, the yellow sticky traps placed on the trunkof \u003cem\u003eAgathis\u003c/em\u003e from New Caledonia plot far away from all other samplings whether they were related to \u003cem\u003eAgathis\u003c/em\u003e or \u003cem\u003eHymenaea\u003c/em\u003e (Fig. 4D).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe assemblage of trapped arthropods includes\u0026nbsp;Acari, Collembola, Hemiptera, Thysanoptera, Hymenoptera, and Coleoptera, among other taxa (see\u0026nbsp;Additional file 2 for arthropod list). The differences between flying and non-flying insects present in amber, copal and Defaunation resin are not significant among the studied samples, except for the arthropods from the Malagasy Defaunation resin of \u003cem\u003eHymenaea\u0026nbsp;\u003c/em\u003eand those from the Australian Eocene amber (Additional file 1: Fig. S3).\u003c/p\u003e\n\u003cp\u003eWe also categorised the arthropods found in all the ambers, copals, and Defaunation resins originating from \u003cem\u003eAgathis\u003c/em\u003e or \u003cem\u003eAgathis\u003c/em\u003e-like trees and \u003cem\u003eHymenaea\u003c/em\u003e trees, and the arthropods trapped by yellow sticky and Malaise traps in the \u003cem\u003eAgathis\u0026nbsp;\u003c/em\u003eand \u003cem\u003eHymenaea\u003c/em\u003e forests (see Additional file 1 and 2 for details of the material and the lists of arthropods, respectively) using a hierarchical clustering (Fig. 5). \u003cem\u003eAgathis\u0026nbsp;\u003c/em\u003eand \u003cem\u003eAgathis\u003c/em\u003e-like resins (Defaunation resins and ambers, respectively) cluster together at the order level and at family level in the case of Diptera (due to the high prevalence of the order Diptera in most samples, their families were analysed separately). Conversely, for New Caledonia, arthropods from both yellow sticky and Malaise traps placed on and close to the \u003cem\u003eAgathis\u0026nbsp;\u003c/em\u003etree trunks, respectively, cluster together with those from amber, copal and Defaunation resin derived from \u003cem\u003eHymenaea\u003c/em\u003e, as well as with the arthropods from both yellow sticky and Malaise traps on and close to the \u003cem\u003eHymenaea\u003c/em\u003e tree trunks.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eAs an additional result, we have updated the list of unbiased amber inclusions from various localities that can be used in future investigations (Additional file 2).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFig. 5 can be placed here\u003c/strong\u003e\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eThe number of amber localities lacking arthropod inclusions is unknown for most amber-bearing regions. This is due to the fact that palaeontological research focuses primarily on systematics and taxonomy, and on palaeoautecological information provided by the bioinclusions, in an attempt to reconstruct forest biocoenoses\u0026nbsp;in deep time, while other aspects of the amber and amber deposits, such as taphonomy and geology, remain unstudied or poorly studied.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eIt is also important to mention that a large number of arthropod inclusions were yielded from some amber deposits discovered several years ago and worked for a long time. Peñacerrada I, for example, is notable for yielding the greatest number of arthropod inclusions from Spanish amber [18, 44]. Notably, it is also the locality from which the most amber has been extracted and prepared (see Table 1). The same is true for the Albian–Cenomanian amber locality from south-west France at Archingeay-Les Nouillers. Recently discovered deposits such as the Eocene amber from Australia or the Miocene amber from New Zealand, produced by \u003cem\u003eAgathis\u003c/em\u003e, currently contain only a few arthropod inclusions [35, 45]. Thus, for some deposits, the absence of arthropod inclusions is\u0026nbsp;most likely due to collection bias. However, it is clear that the majority of the Cretaceous amber deposits does not contain arthropod inclusions or are extremely poor [5]. Some authors have suggested that this circumstance for many Cretaceous amber deposits may be explained by a much more abundant resin exudation under confined conditions in the underground than in aerial conditions [46]. Araucariaceae trees, particularly \u003cem\u003eAgathis\u003c/em\u003e spp., are known for their comparatively abundant production and exudation of resin, not only on their tree trunks, but also within their root systems [3, 37, 47, 48, 49].\u0026nbsp;In contrast to the hundreds of arthropod bioinclusions described from Malagasy copal and Defaunation resin\u0026nbsp;[39], the copals found in regions like New Zealand and New Caledonia (own field. obs.) lack such abundant inclusions, and no arthropod bioinclusions have been described from this material. This can be partly explained by the fact that root resin is unlikely to trap arthropods in confined conditions; given the abundant production of root resin and the resulting mixture of aerial and root copal in these geological deposits, a large proportion of the collected pieces are of the root type. When examining the extant roots of \u003cem\u003eHymenaea\u003c/em\u003e trees and their resin production, a distinct contrast is evident (Additional file 1: Fig. S4). The resin in \u003cem\u003eHymenaea\u003c/em\u003e roots appear intricately interspersed in the sand, forming a crust around the roots ([39] fig. 8). In Madagascar, we observed large \u003cem\u003eHymenaea\u003c/em\u003e trees that had been uprooted by hurricanes, showing their root systems with only small amounts of resin, unlike large resin lumps commonly formed by \u003cem\u003eAgathis\u003c/em\u003e roots [49]. In New Zealand, we have also had the opportunity to study the root systems of large Pleistocene \u003cem\u003eAgathis\u003c/em\u003e at Waipapakauri [49] and Bayleys Beach localities. These large trees are exhumed for their trunk wood, but the roots are abandoned, allowing us to observe large amounts of copal associated with roots (Additional file 1: Fig. S4C, D and E).\u003c/p\u003e\n\u003cp\u003eTo explain the exudation of resin on the tree trunk and the capability to trap arthropods, it is important to note that resin exudation, in general, archives a variety of possible defensive actions, for example, to shield trees from threats such as bark beetles and herbivores, as well as to facilitate wound healing, preventing fungal and bacterial infection, or to prevent desiccation [2, 5, 48, 50, 51]. The variation in resin composition plays a prominent role in those defensive actions. In performing those defensive actions, \u003cem\u003eHymenaea\u003c/em\u003e resin has been also demonstrated to accidentally act as a kind of entomological trap, more precisely as yellow sticky traps that works better for some arthropod groups than for others [29, 30]. Consequently, scientific interest in amber, copal and Defaunation resin has been primarily focused on arthropod inclusions [13]. However, the absence or fewer number of arthropod inclusions in many amber deposits, especially those of \u003cem\u003eAgathis\u003c/em\u003e or \u003cem\u003eAgathis\u003c/em\u003e-like origin, has never been questioned.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe very few arthropod inclusions in \u003cem\u003eAgathis\u003c/em\u003e Defaunation resin compared to the large number of arthropod inclusions in \u003cem\u003eHymenaea\u003c/em\u003e Defaunation resin, along with the different values of exponent b (measure of distribution uniformity) for each resin assemblage, shows that \u003cem\u003eHymenaea\u003c/em\u003e resin is more efficient at trapping arthropods than \u003cem\u003eAgathis\u003c/em\u003e resin and does so spatially more uniformly (see also Additional file 1: Fig. S1 and extended material and methods in Additional file 1). This is consistent with our observations in amber. All arthropod inclusions recorded so far in amber originated from \u003cem\u003eAgathis\u003c/em\u003e or \u003cem\u003eAgathis\u003c/em\u003e-like trees were found in a few pieces/lumps (non-uniform), whereas arthropod inclusions in amber originated from \u003cem\u003eHymenaea\u003c/em\u003e trees are more uniform (Additional file 1: Fig. S1), which means that there are more pieces with at least one inclusion.\u003c/p\u003e\n\u003cp\u003eThe fewer arthropod inclusions and their non-uniform distribution in \u003cem\u003eAgathis\u0026nbsp;\u003c/em\u003eand \u003cem\u003eAgathis\u003c/em\u003e-like resins compared with those observed in \u003cem\u003eHymenaea\u003c/em\u003e resin can be explained mainly through two different aspects, namely 1) resin composition and 2) arthropod attraction or repulsion, hereafter discussed more in detail.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eResin composition\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe variation in resin chemical composition between plant species affects the physical properties of the different resins, namely viscosity or stickiness, and consequently the capability to trap arthropods [28, 34, 37, 52].\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eResin is a complex mixture of volatile compounds, including mono- and sesquiterpenoids, diterpenoids, and sometimes triterpenoids. The diterpenoids originate mainly from conifers (gymnosperms), while triterpenoids (e.g., of the oleanane, ursane and lupane series) and sesquisterpenoids come from angiosperms [53]. These compounds contribute to the fluidity (sesquisterpenoids) of the resin, and determine also its grade of viscosity (diterpenoids) [34]. \u003cem\u003eAgathis\u003c/em\u003e and \u003cem\u003eHymenaea\u003c/em\u003e resins differ in their chemical composition. \u003cem\u003eAgathis\u003c/em\u003e produces a resin type\u0026nbsp;primarily composed of terpenoids\u0026nbsp;[54]. In contrast, \u003cem\u003eHymenaea\u003c/em\u003e produces a resin containing both terpenoids and gum components [37]. The hardening and polymerisation of resin hinge on the number of free radicals within non-volatile compounds, particularly labdatriene diterpenoids, abundant in \u003cem\u003eAgathis\u003c/em\u003e species [34, 55, 56].\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe effectiveness of resin as a defence mechanism under biotic and abiotic environmental stress depends on factors such as drying, flow rate, and viscosity. These factors determine, for example, whether arthropods are pushed out or trapped on the tree trunk, whether a microbial infection can be stopped, or whether desiccation can be prevented. \u0026nbsp;In general, our observations show distinct drying and viscosity characteristics for \u003cem\u003eAgathis\u003c/em\u003e and \u003cem\u003eHymenaea\u003c/em\u003e resins. This suggests that the faster polymerisation of \u003cem\u003eAgathis\u003c/em\u003e resin, resulting in rapid drying (see Fig. 6C), likely leads to fewer arthropods being trapped. Conversely, the characteristics of \u003cem\u003eHymenaea\u003c/em\u003e resin imply an abundant trapping of biological remains (Fig. 6D–I). According to our observations, both resins are fluid at the time of exudation, \u003cem\u003eAgathis\u003c/em\u003e even more than \u003cem\u003eHymenaea\u003c/em\u003e. However, this changes quickly as \u003cem\u003eAgathis\u003c/em\u003e resin dries faster than \u003cem\u003eHymenaea\u003c/em\u003e does\u003cem\u003e.\u003c/em\u003e Whether an arthropod gets stuck depends on it passing by just as the tree begins to produce resin and the organism walking or flying close enough to be trapped.\u0026nbsp;It is quite likely that the fast-drying nature of \u003cem\u003eAgathis\u003c/em\u003e resin prevents arthropods from sticking to it (Figs. 1 and 6).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe previous idea aligns with the sensitivity of \u003cem\u003eAgathis\u003c/em\u003e spp. trees to the \u003cem\u003ePhytophthora\u0026nbsp;\u003c/em\u003espp., a water- and soil-borne oomycete primarily affecting these tree species. This sensitivity prompts a substantial production and exudation of resin as a defence mechanism [3, 5, 57]. In consequence, the trees, both their trunks and roots, are producing large amount of resin. It has been hypothesized that rapid resin hardening may prevent the rapid spread of pathogens on the trunk of a tree [37, 58, 59]. However, \u003cem\u003eAgathis\u003c/em\u003e is also attacked by the defoliating coccids, trips and boring beetles, among others [60]. Therefore, resin exudation in \u003cem\u003eAgathis\u003c/em\u003e is not always induced by a pathogenic agent.\u003c/p\u003e\n\u003cp\u003eOn the other hand, in most angiosperms, including \u003cem\u003eHymenaea,\u003c/em\u003e the resin is mixed with gum (a mixture of hydrophilic polysaccharides), which increases the water-holding capacity of the tissues and prevents desiccation [37, 48, 54]. Gum is rarely observed in conifers and not found in \u003cem\u003eAgathis\u003c/em\u003e spp. [32]. The hydrophobic nature of gum increases the stickiness of the resin, as gum can form bonds and stick when it comes in contact with oily surfaces [61]. This may partly explain why the resins produced by some angiosperms remain sticky for a long time.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFig. 6 can be placed here\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eHow quickly the resin dries depends mainly on the polymerisation rate (low polymerisation rate implies a liquid and sticky resin for a long time), and how long the resin can trap arthropods depends on how long it takes to dry. Therefore, regardless of the amount of resin exudation, the resin will trap arthropods on the entire surface of the accumulated resin for a longer time, making the distribution of arthropod inclusions more uniform (Additional file 1: Fig. S1B), as is the case of \u003cem\u003eHymenaea\u003c/em\u003e resin (Fig. 6D–I). A resin with a high polymerisation rate will remain fluid and sticky for a shorter period of time, giving arthropods a shorter period to be trapped in the resin, resulting in a non-uniform distribution (Additional file 1: Fig. S1C) of arthropod inclusions.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eArthropod attraction or repulsion to resin\u003c/strong\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eAttraction or repulsion toward resins may be physical or chemical in nature and are well documented for some arthropods [40]. From a physical point of view, the “water-imitating” reflection polarisation of resin has been proved for the presence of aquatic adult insects in amber\u0026nbsp;[62]. Although more research is needed to understand how the light reflection of the resin may attract or repel other arthropods, an opaque and white surface (Figs. 1 and 6A, B, and C) may reflect less light than the transparent glue-like resin (Figs. 1 and 6D, E, and F), making \u003cem\u003eAgathis\u003c/em\u003e resin a candidate for being less attractive.\u003c/p\u003e\n\u003cp\u003eFrom a chemical point of view, it has been well documented in some resin-producing conifers that\u0026nbsp;(—)- pinene, a constituent of stem oleoresin, increases in response to heightened insect activity, suggesting a defence mechanism [51]. Abundant — (α)- pinene has also been reported in araucariacean resins [63]. Conifer oleoresin is a complex compound comprising various monoterpenes, sesquiterpenes, and diterpene resin acids. The turpentine portion of the oleoresin includes over 30 monoterpenes and many sesquiterpenes, serving as a defence mechanism by being toxic to some pathogens and insects. Additionally, it aids in sealing plant wounds through the hardening action of diterpenes [51]. Also, the labdanes have been a subject of research due to their potential use as natural insecticides, showcasing antifeedant properties against some Coleoptera, Diptera, and Lepidoptera [64]. Labdanes are diterpenes featuring two aromatic rings in their structure, and are notably abundant in resins derived from the Araucariaceae [65, 66].\u003c/p\u003e\n\u003cp\u003eVolatile terpenoids, including labdanes, play then a dual role in defence by directly deterring herbivores and indirectly attracting their natural predators [67]. Moreover, these compounds also contribute to attracting pollinators for some gymnosperms such as cycads [68]. In the case of\u003cem\u003e\u0026nbsp;Hymenaea,\u003c/em\u003e both in Africa and South America, different resin compounds such as caryophyllene or α-Humulene are present to defend against various caterpillars and termites [40]. The resin of some angiosperm species also attracts insect pollinators\u0026nbsp;or animals (birds and mammals) that can disperse their fruits [48]. The attractiveness or repulsiveness of the resin is an important taphonomic bias in the trapping of some groups of arthropods. However, determining whether \u003cem\u003eHymenaea\u003c/em\u003e can attract arthropods in more abundance than \u003cem\u003eAgathis\u003c/em\u003e, or primarily some particular arthropod groups, requires experimental investigation.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eThe role of yellow sticky and Malaise traps in studying \u003cem\u003eAgathis\u003c/em\u003e resin\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eDifferent orders of arthropods typically exhibit varying proportions in assemblages within amber, copal and Defaunation resins,\u0026nbsp;with Diptera, Hymenoptera, and Coleoptera being the most abundant orders. The type of organism present and its abundance are contingent upon several taphonomic and ecological variables [1,3, 40], and these determined which part of the resiniferous forest is represented in the amber record [30].\u0026nbsp;In this context, we address two primary aspects of arthropod trapping: (1) whether \u003cem\u003eAgathis\u003c/em\u003e resin traps arthropods in a similar way to yellow sticky traps, as observed with \u003cem\u003eHymenaea\u003c/em\u003e resin [30], and (2) whether the arthropod assemblage preserved in \u003cem\u003eAgathis\u003c/em\u003e Defaunation resin is representative of the fauna in the same forest.\u003c/p\u003e\n\u003cp\u003eFrom our actuotaphonomic studies in Madagascar, we know that the arthropod assemblage in the \u003cem\u003eHymenaea\u003c/em\u003e Defaunation resin is comparable to that in the yellow sticky traps placed on \u003cem\u003eHymenaea\u003c/em\u003e trunks. We also know that the assemblage differs notably from the arthropod fauna trapped in Malaise traps placed close to the trunks. This means that the arthropod assemblages trapped by \u003cem\u003eHymenaea\u003c/em\u003e resin represent mainly the fauna living in and around the trunk [30]. This pattern was reinforced by our second sampling in Sacaramy, Madagascar ([39] fig. 1), and shown in Fig. 4B, in which MDS also plots the arthropod assemblages in Defaunation resin from \u003cem\u003eHymenaea\u003c/em\u003e close to the arthropod assemblages in yellow sticky traps.\u0026nbsp;On the contrary, MDS plots arthropod assemblages (at order level) in resin from \u003cem\u003eAgathis\u003c/em\u003e far away from the arthropod assemblages in yellow sticky and Malaise traps in \u003cem\u003eAgathis\u003c/em\u003e (Fig. 4). This stark contrast shows that \u003cem\u003eAgathis\u003c/em\u003e resins exhibit a different trapping bias as an entomological trap like the yellow sticky traps.\u003c/p\u003e\n\u003cp\u003eWe found that arthropods preserved in amber and in Defaunation resin from \u003cem\u003eAgathis\u003c/em\u003e and \u003cem\u003eAgathis\u003c/em\u003e-like trees form distinct clusters at both the order and family levels (Fig. 5) (the latter focussed on dipteran families herein). In contrast, arthropods from yellow sticky and Malaise traps that were placed on and near \u003cem\u003eAgathis\u003c/em\u003e trees cluster with those from amber, copal and Defaunation resin of \u003cem\u003eHymenaea\u003c/em\u003e origin. They also cluster with the\u0026nbsp;arthropods from yellow sticky and Malaise traps on and near\u0026nbsp;\u003cem\u003eHymenaea\u003c/em\u003e trees. This reinforces the idea that the resin of \u003cem\u003eHymenaea\u003c/em\u003e acts as an entomological trap (\u003cem\u003ei.e\u003c/em\u003e., it has a trapping effect similar to yellow sticky traps), and that there is difference in the ways \u003cem\u003eAgathis\u003c/em\u003e and \u003cem\u003eHymenaea\u003c/em\u003e resins trap arthropods.\u003c/p\u003e\n\u003cp\u003eThe arthropods trapped in \u003cem\u003eAgathis\u003c/em\u003e Defaunation resin are mostly Arachnida or non-flying Hexapoda, except for one Thysanoptera and one Diptera remain. In contrast, the samples of Defaunation resin collected from \u003cem\u003eHymenaea\u003c/em\u003e tree trunks contain abundant Diptera\u0026nbsp;(Additional file 2). However, as presented in the results, there was no a representative difference between flying and non-flying insects found in amber, copal, and Defaunation resin across the studied samples. Therefore, it is likely that this finding is due to the scarcity of material and needs more investigation.\u003c/p\u003e\n\u003cp\u003eThe number of Diptera specimens was very high in the yellow sticky traps placed on \u003cem\u003eAgathis\u003c/em\u003e, this may be a reason why they plot close to the Malaise traps (Fig. 4C and Additional file 1: Fig. S5C), since Malaise traps are considered a successful method to collect flies [69]. Within the Diptera, the family Phoridae, overwhelmingly dominated the yellow sticky traps placed on \u003cem\u003eAgathis\u003c/em\u003e, comprising nearly 90% of dipterans (Additional file 1: Fig. S2). As our collection took place in November and December, the humid months in New Caledonia, seasonality probably played an important role in determining abundance. Phoridae typically exhibit higher numbers during humid periods [70]. While other dipterans, namely Chloropidae, Sciaridae, and Cecidomyiidae, were also abundant in the yellow sticky traps placed at 1m height, their numbers are small in comparison to Phoridae. This may be a reason why they plot separately from Malaise traps (Fig. 4D and Additional file 1: Fig. S5D). Although not as abundant as in yellow sticky traps on \u003cem\u003eAgathis\u003c/em\u003e, the family Phoridae was also abundant in yellow sticky traps placed on \u003cem\u003eHymenaea,\u003c/em\u003e and this family is also abundant in amber, particularly in Miocene ambers (\u003cem\u003ee.g\u003c/em\u003e., [71]). Phoridae flies can be collected using a variety of traps [29, 72, 73]; however, yellow sticky traps seem to be the most effective one for collecting these flies [74, 75]. Small vertebrates, such as lizards, can also become trapped in yellow sticky traps, drawing in phorid flies that are attracted to decaying animal matter [41, 74, 76]. This phenomenon may also partly account for the high abundance of dipterans, particularly phorid flies, observed in New Caledonia in yellow sticky traps. Surprisingly, Phoridae is not present in \u003cem\u003eAgathis\u003c/em\u003e Defaunation resin, and Diptera is notably underrepresented in that resin (Additional file 2). Resin production is affected by various factors, including temperature, humidity, growth, carbon assimilation, soil nutrients, or injuries [3, 31]. Therefore, it is not possible to establish a correlation between seasonality and the absence of phorid flies in the resin.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eGiven that \u003cem\u003eAgathis\u003c/em\u003e and \u003cem\u003eHymenaea\u003c/em\u003e resins trap arthropods differently, a pattern inferred for extant and deep-time ecosystems, it is crucial to consider these different trapping biases (Fig. 1) when comparing fossil assemblages preserved in ambers from these two botanical sources.\u003c/p\u003e\n\u003cp\u003eSeveral important factors influence the trapping of arthropods by \u003cem\u003eAgathis\u003c/em\u003e resin. We consider that the most important factor is rapid drying, which results in a higher viscosity and the acquisition of a whitish patina on resin exuded from the trunk—even though \u003cem\u003eAgathis\u003c/em\u003e resin is much more fluid than \u003cem\u003eHymenaea\u003c/em\u003e resin when it is originally exuded.\u0026nbsp;Rapid drying\u0026nbsp;prevents a large number of arthropods from being present as bioinclusions in the \u003cem\u003eAgathis\u003c/em\u003e Defaunation resin, and it results in a statistically non-uniform spatial distribution of these. In contrast, \u003cem\u003eHymenaea\u003c/em\u003e resin has a higher viscosity when exuded, but it takes much longer to dry, and remains transparent; the slower drying allows arthropods to be abundant as bioinclusions in the resin, making their spatial distribution statistically more uniform. This leads us to conclude that \u003cem\u003eAgathis\u003c/em\u003e resin does not act as an effective entomological trap for arthropods, unlike \u003cem\u003eHymenaea\u003c/em\u003e resin (Fig. 1). This suggests that the arthropods trapped in \u003cem\u003eAgathis\u003c/em\u003e Defaunation resin (thanatocoenosis) (which eventually become amber - oryctocoenosis) do not reflect the fauna that lived in or surrounding the resin-producing trees (biocoenosis), unlike \u003cem\u003eHymenaea\u0026nbsp;\u003c/em\u003eresin. This taphonomic pattern has critical implications for the interpretation of Cretaceous forest biocoenoses with an \u003cem\u003eAgathis\u003c/em\u003e or \u003cem\u003eAgathis\u003c/em\u003e-like origin. Although we discuss that \u003cem\u003eAgathis\u003c/em\u003e resin is less effective at trapping arthropods than \u003cem\u003eHymenaea\u003c/em\u003e resin, we could not determine frequent ecological groups (arthropod guilds) trapped by \u003cem\u003eAgathis\u003c/em\u003e resin using the small sample set that is available. Similarly, the fossil assemblages of arthropod bioinclusions in Eocene or Miocene \u003cem\u003eAgathis\u003c/em\u003e ambers do not provide guild information due to the scarcity of deposits. A follow-up investigation (beyond collecting more \u003cem\u003eAgathis\u003c/em\u003e resin with bioinclusions) could involve defining the criteria required to recognise guilds and categorising the inclusions found in Cretaceous amber, in order to determine the most prevalent types of arthropods in this amber type.\u003c/p\u003e\n\u003cp\u003eThe abundance of Cretaceous amber and Quaternary copal localities featuring numerous lumps but few bioinclusions, along with the non-uniform distribution of rare arthropod inclusions, can be partly attributed to substantial resin exudation from \u003cem\u003eAgathis\u003c/em\u003e root systems. This exudation forms both large and small lumps in confined conditions.\u0026nbsp;Comparable profuse resin production has not been observed from the root system of \u003cem\u003eHymenaea\u003c/em\u003e trees.\u0026nbsp;Several unanswered questions still require further investigation, such as how resin attracts or repels some arthropods influencing the number of arthropods trapped, and the content of bioinclusions in the oryctocoenosis. Furthermore, this influence needs to be considered with respect to whether the trees involved were from the \u003cstrong\u003egenera\u003c/strong\u003e \u003cem\u003eAgathis\u003c/em\u003e or \u003cem\u003eHymenaea, or from some close relatives.\u0026nbsp;\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eFurther studies and more accurate taphonomic data are needed to identify the conditions in which arthropods were trapped in other ancient and modern resins from coniferous and leguminous trees, and to determine and how the oryctocoenosis originated.\u003c/p\u003e"},{"header":"Methods","content":"\u003cp\u003e\u003cstrong\u003eMaterial\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe collected living arthropods using yellow sticky and Malaise traps, following the methodology outlined by Sol\u0026oacute;rzano-Kraemer et al. [30]. These traps were installed on and\u0026nbsp;close to \u003cem\u003eAgathis\u003c/em\u003e \u003cem\u003elanceolata\u003c/em\u003e (Lindl. ex Sebert \u0026amp; Pancher) Warb., 1900 trees in Bon Secours forest, adjacent to the Rivi\u0026egrave;re Bleue Provincial Park (New Caledonia), in 2016 (November \u0026ndash; December, warm and rainy season), and on and close to \u003cem\u003eHymenaea verrucosa\u003c/em\u003e Gaertner, 1791 in Madagascar, Mananjary region (between Nosy Varika and Ambahy), in 2013 (September- October, warm and rather dry season), and Sacaramy (near to Diego Suarez), in 2015 (April \u0026ndash; May, warm and rainy season) (Additional file 1: Fig. S6 and extended material and methods in Additional file 1). In total, we collected arthropods around four \u003cem\u003eAgathis\u003c/em\u003e trees and eight \u003cem\u003eHymenaea\u003c/em\u003e trees (four \u003cem\u003eHymenaea\u003c/em\u003e trees per campaign). During each collection trip, we displayed 45 yellow sticky traps at three different heights on each tree for eight days, as well as four Malaise traps, one for each of four selected trees. We added to our analyses the data extracted from Sol\u0026oacute;rzano-Kraemer et al. [29], who also collected arthropods with yellow sticky and Malaise traps in 2010, 2011 and 2012 on and close to \u003cem\u003eHymenaea courbaril\u0026nbsp;\u003c/em\u003eLinn\u0026eacute;, 1753 in La Rinconada National Park in Mexico. The list of sampled arthropods can be seen in the Additional file 2.\u003c/p\u003e\n\u003cp\u003eThroughout the manuscript we use the terms amber, copal, and Defaunation resin \u003cem\u003esensu\u003c/em\u003e Sol\u0026oacute;rzano-Kraemer et al. [13]. In this system, amber is older than 2.58 Ma, copal is 2.58 Ma to 1760 AD (Anno Domini), and Defaunation resin is the resin produced after 1760 AD.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eWe sampled Defaunation resins from eight \u003cem\u003eAgathis lanceolata\u0026nbsp;\u003c/em\u003etrees, and from 28 \u003cem\u003eA. ovata\u003c/em\u003e (C. Moore ex Veill.) Warb., 1900 trees in New Caledonia. In Madagascar, resin was collected from 11 \u003cem\u003eH. verrucosa\u003c/em\u003e trees in the\u0026nbsp;Mananjary region in 2013 [30] and from 10 \u003cem\u003eH. verrucosa\u003c/em\u003e trees in Sacaramy (for the precise location and map see [39], fig. 1) in 2015. All Defaunation resin samples were collected from tree trunks. From Mexico, no Defaunation resin was sampled from \u003cem\u003eHymenaea courbaril\u003c/em\u003e trees because resin exudates were virtually absent [29].\u003c/p\u003e\n\u003cp\u003eFor the purposes of this paper, we do not distinguish between the different extant species of \u003cem\u003eAgathis\u003c/em\u003e and \u003cem\u003eHymenaea\u003c/em\u003e involved in the collection work, or between the different ancient tree species proposed as the origin of the resin in the past (in the case of amber derived from \u003cem\u003eHymenaea\u003c/em\u003e, \u003cem\u003ee.g\u003c/em\u003e. \u003cem\u003eH. protera\u003c/em\u003e\u0026dagger; Poinar, 1999, \u003cem\u003eH. mexicana\u003c/em\u003e\u0026dagger; Poinar and Brown, 2002, and \u003cem\u003eH. allendis\u003c/em\u003e\u0026dagger; Calvillo-Canadell et al., 2010). We use \u0026quot;\u003cem\u003eAgathis\u003c/em\u003e\u0026quot; to refer to both living trees and fossil resins derived from \u003cem\u003eAgathis\u003c/em\u003e trees. \u0026quot;\u003cem\u003eAgathis\u003c/em\u003e-like\u0026quot; refers to fossil resins derived from ancient plants of the genus \u003cem\u003eAgathis\u003c/em\u003e or only related to it. Cheirolepidiaceous ambers are also included as they are highly similar in chemistry to \u003cem\u003eAgathis\u003c/em\u003e resins [8, 77]. Since the proposed botanical origin of Miocene amber is not questioned, we use \u003cem\u003eHymenaea\u003c/em\u003e to refer to both living trees and resins, as well as fossil resins derived from \u003cem\u003eHymenaea\u003c/em\u003e.\u003c/p\u003e\n\u003cp\u003eWe compared the arthropod assemblages obtained from yellow sticky and Malaise traps and those preserved within Defaunation resin from extant trees, with the arthropod assemblages preserved in amber from Late and Early Cretaceous and Middle Miocene from different localities around the world. All the amber, copal, and Defaunation resin collections included in the present study have been selected because they are unbiased and collected for scientific purposes; they have been collected in the field without prior selection of arthropod inclusions and/or whether the pieces/lumps containing arthropod inclusions or not. Searching for arthropod inclusions and preparing the pieces is a process that has been carried out in laboratory. With this purpose, we persuaded a detailed composition of the arthropod assemblages\u0026nbsp;identified from Cretaceous amber from Spain and France, Eocene amber from Australian, Oligocene and Miocene amber from New Zealand, Miocene amber from the Dominican Republic and Mexico, copal and Defaunation resin from the Dominican Republic. Collections with the specification of the inclusions per gram of resin are mentioned in Table 1.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 1 can be placed here. The references in the table are numbered from this point onwards.\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe term bioinclusion in amber, copal, and Defaunation resin includes all organismal remains that can be found in fossil\u0026nbsp;resins. However, since arthropod inclusions are the only bioinclusions included in our analyses, we will use the term arthropod inclusions to refer to the bioinclusions we study here.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe copal and Defaunation resin samples were polished and prepared in the same manner as amber [85, 86] to correctly identify the bioinclusions.\u0026nbsp;However, for some lumps, it was only necessary to create a small viewing window to observe their contents.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eImaging\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe photographs were performed with digital cameras Canon EOS 40D and Canon EOS 70D. Figures were performed using Adobe Photoshop software (version 25.4 www.adobe.com).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData processing\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe data used in this study were frequency data of taxa and experimental groups (amber, copal, and Defaunation resin, and yellow sticky and Malaise traps). Multivariate analyses were used to evaluate the different hypotheses of the study, namely, multidimensional scaling (MDS), and representation of the relationships for each experimental group in the form of a correlation heat-map or correlation network.\u003c/p\u003e\n\u003cp\u003eStatistical analyses were performed using different R functions and libraries [87]. The BDbiost3 library for R [ 88, 89] was used for exploratory data analysis, and multidimensional scaling used functions LinesMDS() (see Additional file 1 for more detail on the statistical methods used [90, 91]). All data used for statistical work are available in Additional file 2.\u003c/p\u003e\n\u003cp\u003eTo estimate the degree of uniformity of arthropod inclusions in Defaunation resin from \u003cem\u003eAgathis\u003c/em\u003e and \u003cem\u003eHymenaea\u003c/em\u003e, we estimated the probability density function (PDF) that a piece lacks arthropod inclusions given the mass of the piece (see Additional file 1 for a discussion of this methodology [92]). For this, we measured the mass of pieces with an error of 0.01g and we counted the number of arthropod inclusions in each piece (see Additional file 2). Then, we calculated the frequencies of pieces without arthropod inclusions and with a mass in intervals of 0.01g for the Defaunation resins from the \u003cem\u003eAgathis\u003c/em\u003e and \u003cem\u003eHymenaea\u003c/em\u003e trees. These frequencies were associated with the conditional\u0026nbsp;probability of finding a piece of mass m, given that it does not contain arthropod inclusions. Bayes\u0026apos; theorem was then used to obtain the conditional probability of not having arthropod inclusions given that the piece has mass m. Finally, we fit the resulting probabilities with power laws of the form \u0026nbsp; by first obtaining the logarithm of the data, then using standard least squares algorithm with the fitting model log(a) - b log(m) to obtain the values of a and b for both collections. We used b as a measurement of the uniformity of arthropod inclusions. The exponent b measures the uniformity of arthropod inclusions, while the parameter a is just the estimated value of the PDF that a piece of resin has no arthropod inclusions within one gram of resin, and was only used to fit the data correctly.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAbbreviations for Figure 4\u003c/strong\u003e: \u003cstrong\u003eAA\u003c/strong\u003e\u003cstrong\u003eES\u003c/strong\u003e: Amber from Ari\u0026ntilde;o, Spain; \u003cstrong\u003eAAFR\u003c/strong\u003e: Amber from Archingeay-Les Nouillers, France, mentioned in Perrichot et al. [21]; \u003cstrong\u003eAAIFR\u003c/strong\u003e: Amber Aix island, France; \u003cstrong\u003eAAPES\u003c/strong\u003e: Amber from Arroyo de la Pascueta, Spain; \u003cstrong\u003eABFR\u003c/strong\u003e: Amber La Buzinie, France; \u003cstrong\u003eACFR\u003c/strong\u003e: Amber Cadeuil, France; \u003cstrong\u003eADCO\u003c/strong\u003e: Amber Doumanga, Congo; \u003cstrong\u003eADOG.P\u003c/strong\u003e: Dominican amber collection from the private collection mentioned in Poinar [93]; \u003cstrong\u003eADOJ.C\u003c/strong\u003e: Dominican amber from the Jorge Caridad private collection; \u003cstrong\u003eAFFR\u003c/strong\u003e: Amber Fouras, France; \u003cstrong\u003eAFTFR\u003c/strong\u003e: Amber Fourtou, France; \u003cstrong\u003eAHES\u003c/strong\u003e: Amber from La Hoya, Spain; \u003cstrong\u003eAMX\u003c/strong\u003e: Mexican amber collections mentioned in Sol\u0026oacute;rzano-Kraemer et al. [29]; \u003cstrong\u003eAPES\u003c/strong\u003e: Amber form Pe\u0026ntilde;acerrada I, Spain; \u003cstrong\u003eARFR\u003c/strong\u003e: Amber Les Renardi\u0026egrave;res, France; \u003cstrong\u003eASES\u003c/strong\u003e: Amber from El Soplao, Spain; \u003cstrong\u003eASJES\u003c/strong\u003e: Amber from San Just, Spain; \u003cstrong\u003eASFR\u003c/strong\u003e: Amber Salignac, France; \u003cstrong\u003eCDO\u003c/strong\u003e: Copal collected in 2019 in Cotu\u0026iacute;, Dominican Republic; \u003cstrong\u003eCTZ\u003c/strong\u003e: Copal from Tanzania; \u003cstrong\u003eMMG\u003c/strong\u003e: Malaise trap installed close to \u003cem\u003eHymenaea\u0026nbsp;\u003c/em\u003ein 2013 in Madagascar; \u003cstrong\u003eMMX\u003c/strong\u003e: Malaise trap installed close to \u003cem\u003eHymenaea\u0026nbsp;\u003c/em\u003esince 2010 to 2012 in Mexico; \u003cstrong\u003eMNC\u003c/strong\u003e: Malaise trap installed close to \u003cem\u003eAgathis\u0026nbsp;\u003c/em\u003ein 2016 in New Caledonia; \u003cstrong\u003eRMG1\u003c/strong\u003e: Defaunation resin collected from \u003cem\u003eHymenaea\u0026nbsp;\u003c/em\u003etree trunks in 2013 in Madagascar; \u003cstrong\u003eRMG2\u003c/strong\u003e: Defaunation resin collected from \u003cem\u003eHymenaea\u003c/em\u003e tree trunks in 2015 in Madagascar; \u003cstrong\u003eRNC\u003c/strong\u003e: Defaunation resin collected from \u003cem\u003eAgathis\u003c/em\u003e tree trunks in 2016 in New Caledonia; \u003cstrong\u003eST0MG\u003c/strong\u003e, \u003cstrong\u003eST1MG\u003c/strong\u003e, \u003cstrong\u003eST2MG\u003c/strong\u003e: Yellow sticky traps placed at 0, 1 and 2 meters on \u003cem\u003eHymenaea\u0026nbsp;\u003c/em\u003etree trunks in Madagascar, respectively; \u003cstrong\u003eST0NC\u003c/strong\u003e,\u003cstrong\u003e\u0026nbsp;ST1NC\u003c/strong\u003e, \u003cstrong\u003eST2NC\u003c/strong\u003e: Yellow sticky traps placed at 0, 1 and 2 meters in 2016 on \u003cem\u003eAgathis\u0026nbsp;\u003c/em\u003etree trunks in New Caledonia, respectively; \u003cstrong\u003eSTTMG\u003c/strong\u003e: Total yellow sticky traps placed around \u003cem\u003eHymenaea\u0026nbsp;\u003c/em\u003ein 2013 in Madagascar; \u003cstrong\u003eSTTMX\u003c/strong\u003e: Total yellow sticky traps placed around \u003cem\u003eHymenaea\u0026nbsp;\u003c/em\u003etree trunks in 2012 in Mexico; \u003cstrong\u003eSTTNC\u003c/strong\u003e: Total yellow sticky traps placed around \u003cem\u003eAgathis\u0026nbsp;\u003c/em\u003etree trunks in 2016 in New Caledonia.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAcknowledgements\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe thank the family Caridad, owners of the \u003cem\u003eMuseo Mundo del \u0026Aacute;mbar\u003c/em\u003e in Santo Domingo, S.B. Brower, F.A. Aquel Fern\u0026aacute;ndez, and Y.H. Shih (Dominican Republic) for their invaluable support, assistance during the scientific fieldwork, and donation of amber and copal/Defaunation resin pieces. Special thanks are given to R. Ravelomanana, M. Asensi, M. Madiomanana, and J. Andrianabo (Madagascar) for their dedicated assistance during fieldwork. Gratitude is expressed to Dr T. Rakotondrazafy, Director of the D\u0026eacute;part. de Pal\u0026eacute;ontologie et Anthropologie Biologique, and Dr E.M. Randrianarisoa, Director of the D\u0026eacute;part. d\u0026rsquo;Entomologie, both at the Universit\u0026eacute; d\u0026rsquo;Antananarivo (Madagascar), for their valuable help and advice in navigating administrative arrangements. The authors\u0026nbsp;wish to acknowledge the contribution of the team at the Malagasy Institute for the Conservation of Tropical Environments (ICTE/MICET) for their support in the administrative development of the fieldwork in Madagascar. Thanks also go to J. Manaut\u0026eacute; and J. Delafen\u0026ecirc;tre from Parc Provincial de la Rivi\u0026egrave;re Bleue, New Caledonia, for their support and assistance during fieldwork. The Direction de l\u0026rsquo;Environnement (DENV) Province Sud from Nouvelle Cal\u0026eacute;donie is acknowledged for granting the necessary fieldwork permits. Appreciation is extended to R. Kunz of the Senckenberg Research Institute (SMF) for his efforts in sorting, preparing and cataloguing the resin and copal collection deposited at the SMF and for the photos in the Figure 6H and I. Further gratitude is directed toward R. L\u0026oacute;pez del Valle (Spain) for their contribution to sorting, preparing, and cataloguing the Spanish amber. Thanks are due to Eduardo Esp\u0026iacute;lez from Fundaci\u0026oacute;n Conjunto Paleontol\u0026oacute;gico de Teruel-Din\u0026oacute;polis for cataloguing and curation of the Cretaceous Spanish amber from Teruel, and the director of that institution Dr Alberto Cobos. We would like to thank the three anonymous reviewers for their valuable feedback and corrections, which helped to improve the manuscript. We would like to extend our gratitude to Jos\u0026eacute; Antonio Pe\u0026ntilde;as for his artistic illustration of Fig. 1.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAuthors agree to publication.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis work was supported by the Spanish Ministerio de Ciencia, Innovaci\u0026oacute;n y Universidades scientific projects\u0026nbsp;CGL2017-84419/ AEI/FEDER, UE, and\u0026nbsp;PID2022-137316NB, funded by MICIU/AEI/10.13039/501100011033 and by ERDF/EU; by DEGAPA-UNAM through the project PAPIIT IN113923,\u0026nbsp;by the\u0026nbsp;programme RYC2022-037026-I, funded by AEI/10.13039/ 501100011033 and the FSE+;\u0026nbsp;by the Consejer\u0026iacute;a de Industria, Turismo, Innovaci\u0026oacute;n, Transporte y Comercio of the Gobierno de Cantabria through the semi-public enterprise EL SOPLAO S.L. [research agreement #20963 with Universitat de Barcelona and research contract Ref. VAPC 20225428 to Instituto Geol\u0026oacute;gico y Minero de Espa\u0026ntilde;a \u0026ndash; Consejo Superior de Investigaciones Cient\u0026iacute;ficas, both 2022\u0026ndash;2025];\u0026nbsp;the German\u0026nbsp;VolkswagenStiftung (Project N. 90946), and the DFG project 457837041 (SO 894/6-1).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData availability\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll the data needed to evaluate the conclusions of the paper are available in the paper and in the supplementary information files. The amber from \u0026ldquo;El Valle \u0026ndash; 7 Ca\u0026ntilde;adas\u0026rdquo; and San Rafael, Dominican Republic have been acquired directly in the mine by MMS-K, XD and EP. The copal/Defaunation resin from Cotu\u0026iacute;, Dominican Republic, have been acquired by Y.H. Shih. These amber and copal/Defaunation resin will be housed in the Museo Nacional de Historia Natural \u0026lsquo;Prof. Eugenio de Jes\u0026uacute;s Marcano\u0026rsquo; in Santo Domingo, Dominican Republic. Correspondence for material related to this paper can be sent to M\u0026oacute;nica M. Sol\u0026oacute;rzano-Kraemer ([email protected]), Enrique Pe\u0026ntilde;alver ([email protected]), and Xavier Delcl\u0026ograve;s ([email protected]).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors\u0026rsquo; contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eM.M.S-K., E.P. and X.D. conceived the idea, designed the methodology, analysed the data and drafted the manuscript. M.M.S-K., designed the first draft. A.M-G. and A.S.K. performed the statistical analysis. M.M.S-K., E.P., X.D., M.C.M.H., D.P., A.A., V.P. and M.P. identified the specimens, and provided the list of specimens, M.M.S-K., E.P., X.D., E.B. and R.G. carried out the field work.\u0026nbsp;M.M.S.-K., E.B., E.P. and X.D. acquired and managed project funding.\u0026nbsp;All authors contributed critically to the drafts and gave final approval of the manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare no competing interests.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthics statements\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eSampling materials were acquired through permits from the Government of New Caledonia and Madagascar, and the relevant permit numbers are as follows: In New Caledonia the Direction de l\u0026rsquo;Environnment de la Province Sud (DENV) permitted us to work, the sampling and exportation Permit is 3021-2016/ARR/DENV; and in Madagascar, The Minist\u0026egrave;re de l\u0026rsquo;Environnement, de l\u0026rsquo;\u0026Eacute;cologie et des For\u0026ecirc;ts gave us permission to work in the Malagasy protected areas, the sampling Permits are 192/13 and N. 060/15, with exportation permits 192/13/MEF/SG/DGF/DCB.SAP/SCB. 060/15/ MEEF/SG/DGF/DCB.SAP/SCB.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eMartínez-Delclòs X, Briggs DE, Peñalver E. 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Naturalist 1981;106: 53–66.\u003c/li\u003e\n\u003cli\u003eSolórzano-Kraemer MM, Brown BV. \u003cem\u003eDohrniphora\u003c/em\u003e (Diptera: Phoridae) from the Miocene Mexican and Dominican ambers with a paleobiological reconstruction. Insect Syst Evol. 2018;49(3):299–327.\u003c/li\u003e\n\u003cli\u003eBorkent A, Brown B, Adler PH, Amorim DDS, Barber K, Bickel D, et al. Remarkable fly (Diptera) diversity in a patch of Costa Rican cloud forest: Why inventory is a vital science. Zootaxa\u003cem\u003e.\u003c/em\u003e 2018;4402(1):53–90.\u003c/li\u003e\n\u003cli\u003eBrown BV, Borkent A, Adler PH, Amorim DDS, Barber K, Bickel D. Comprehensive inventory of true flies (Diptera) at a tropical site. Commun Biol. 2018;1(1):21.\u003c/li\u003e\n\u003cli\u003ePuckett RT, Calixto AA, Reed JJ, McDonald DL, Drees BB, Gold RE. Effectiveness comparison of multiple sticky-trap configurations for sampling \u003cem\u003ePseudacteon\u003c/em\u003e spp. phorid flies (Diptera: Phoridae). Environ Entomol\u003cem\u003e.\u003c/em\u003e 2013;4:763–9.\u003c/li\u003e\n\u003cli\u003ePuckett RT, Calixto A, Barr CL, Harris M. Sticky traps for monitoring \u003cem\u003ePseudacteon\u003c/em\u003e parasitoids of \u003cem\u003eSolenopsis\u003c/em\u003e fire ants. Environ Entomol\u003cem\u003e.\u003c/em\u003e 2014;36(3):584–8.\u003c/li\u003e\n\u003cli\u003eCornaby BW. Carrion reduction by animals in contrasting tropical habitats. Biotropica\u003cem\u003e.\u003c/em\u003e 1974;51:51–63.\u003c/li\u003e\n\u003cli\u003eMenor-Salván C, Najarro M, Velasco F, Rosales I, Tornos F, Simoneit BR. Terpenoids in extracts of Lower Cretaceous ambers from the Basque-Cantabrian Basin (El Soplao, Cantabria, Spain): paleochemotaxonomic aspects. Org Geochem. 2010;41(10):1089–1103.\u003c/li\u003e\n\u003cli\u003eGirard V, Neraudeau D, Breton G, Morel N. Palaeoecology of the Cenomanian amber forest of Sarthe (western France). Geol Acta.2013;11(3): 321–330.\u003c/li\u003e\n\u003cli\u003eNéraudeau D, Allain R, Perrichot V, Videt B, de Broin FDL, Guillocheau F. Découverte d’un dépôt paralique à bois fossiles, ambre insectifère et restes d’Iguanodontidae (Dinosauria, Ornithopoda) dans le Cénomanien inférieur de Fouras (Charente-Maritime, Sud-Ouest de la France). Comptes Rendus Palevol 2003;2(3):221–230.\u003c/li\u003e\n\u003cli\u003eNéraudeau D, Vullo R, Gomez B, Girard V, Lak M, Videt B et al. Amber, plant and vertebrate fossils from the Lower Cenomanian paralic facies of Aix Island (Charente-Maritime, SW France). Geodiversitas 2009;31(1):13–27.\u003c/li\u003e\n\u003cli\u003eNeraudeau D, Perrichot V, Colin JP, Girard V, Gomez B, Guillocheau F. A new amber deposit from the Cretaceous (uppermost Albian-lowermost Cenomanian) of southwestern France. Cretac Res. 2008;29(5–6):925–929.\u003c/li\u003e\n\u003cli\u003eChaler R, Grimalt JO. Fingerprinting of Cretaceous higher plant resins by infrared spectroscopy and gas chromatography coupled to mass spectrometry. Phytochem Anal\u003cem\u003e.\u003c/em\u003e 2005;16(6):446–50.\u003c/li\u003e\n\u003cli\u003ePeñalver E, Fernández BG, del Valle RL, Barrón E, Fernández RPL, Rodrigo A, et al. Un nuevo yacimiento de ámbar cretácico en Asturias (norte de España): Resultados preliminares de la excavación paleontológica de 2017 en La Rodada (La Manjoya). Yacimientos Paleontológicos Excepcionales en la Península Ibérica: XXXIV Jornadas de Paleontología y IV Congreso Ibérico de Paleontología. Soc Esp Paleontol. 2018;289–99.\u003c/li\u003e\n\u003cli\u003eBouju V, Perrichot V. A review of amber and copal occurrences in Africa and their paleontological significance. Bull. Soc. geol. Fr. 2020;191(17):1–11.\u003c/li\u003e\n\u003cli\u003eCorral JC, López del Valle R, Alonso J. El ámbar cretácico de Álava (Cuenca Vasco-Cantábrica, Norte de España). Su colecta y preparación. Est Mus Cienc Nat de Álava 1999;14 Núm. Espec. 2: 7–21.\u003c/li\u003e\n\u003cli\u003eSadowski EM, Schmidt AR, Seyfullah LJ, Solórzano-Kraemer MM, Neumann C, Perrichot V, et al. Conservation, preparation and imaging of diverse ambers and their inclusions. Earth-Sci Rev. 2021;220:103653. https://doi.org/10.1016/j.earscirev.2021.103653\u003c/li\u003e\n\u003cli\u003eR Core Team. R: A language and environment for statistical computing. Vienna, Austria: R Foundation for Statistical Computing; 2024. https://www.R-project.org/ \u003c/li\u003e\n\u003cli\u003eMonleón-Getino A, Rodríguez-Casado C, Mendez-Viera J. How to calculate number of samples in the design of pre/pro-biotics studies (metagenomic studies). III WorkShop Insa-UB 2017; 1–2. doi:10.13140/RG.2.2.27611.67367 \u003c/li\u003e\n\u003cli\u003eMonleón-Getino A. T. Library for R BDSBIOST3: Machine Learning and Advanced Statistical Methods for Omic categorical analysis and others. 2020. https://github.com/amonleong/BDSbiost3 \u003c/li\u003e\n\u003cli\u003eHout MC, Papesh MH, Goldinger SD. Multidimensional scaling. Wiley Interdiscip Rev Cogn Sci. 2013;4(1):93–103. doi:10.1002/wcs.1203.\u003c/li\u003e\n\u003cli\u003eRodríguez-Casado C, Monleón-Getino T, Alcolea M. A priori groups based on Bhattacharyya distance and partitioning around medoids algorithm (PAM) with applications to metagenomics. IOSR J Math. 2017;13(3):24–32.\u003c/li\u003e\n\u003cli\u003eRoss SM. A first course in probability. 5th ed. USA: Pearson; 1997.\u003c/li\u003e\n\u003cli\u003ePoinar GO, Poinar R. The amber forest: a reconstruction of a vanished world. New Jersey: Princeton University Press; 1999\u003c/li\u003e\n\u003c/ol\u003e"},{"header":"Tables","content":"\u003cp\u003e\u003cstrong\u003eTable 1.\u003c/strong\u003e \u003cstrong\u003eNumber of arthropod inclusions per gram in amber, copal, or Defaunation resin that are reported in the literature and own data.\u003c/strong\u003e The amber, copal, and Defaunation resin (collected directly from the trees) from the different areas were not pre-selected in terms of containing or not containing arthropod inclusions. *The table includes collections that are unbiased in terms of arthropods per gram; unbiased collections only in terms of no pre-selection of arthropod species are not included here.** Stilwell et al. [35] do not specify a source for this amber, but its age and provenance suggest \u003cem\u003eAgathis\u003c/em\u003e sp.\u003c/p\u003e\n\u003ctable border=\"0\" cellspacing=\"0\" cellpadding=\"0\" width=\"642\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eLocality/Area of collection\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eAge of resin\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eResiniferous tree\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eWeight / Pieces\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eN. of arthropod inclusions\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eCitation\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eMananjary region (between Nosy Varika and Ambahy), Madagascar\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eResin collected in 2013\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cem\u003eHymenaea verrucosa\u0026nbsp;\u003c/em\u003e(Caesalpiniaceae)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e800.5 grams\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e1743\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eSolórzano-Kraemer et al. [30]\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eSacaramy (close to Antsiranana, Diego Suarez), Madagascar\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eResin collected in 2015\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cem\u003eHymenaea verrucosa\u0026nbsp;\u003c/em\u003e(Caesalpiniaceae)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e1500 grams\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e2141\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eOwn data\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eCol de Yaté South Province (Gramseat South), New Caledonia\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eResin collected in 2016\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cem\u003eAgathis ovata\u0026nbsp;\u003c/em\u003e(Araucariaceae)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e1627.1 grams\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e40\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eOwn data\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eBon Secours (close to Rivière Bleue Provincial Park, South Province, Gramseat South), New Caledonia\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eResin collected in 2016\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cem\u003eAgathis lanceolata\u0026nbsp;\u003c/em\u003e(Araucariaceae)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e991.6 grams\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eOwn data\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eCopal / Defaunation resin from Cotuí, Dominican Republic\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eUnknown\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cem\u003eHymenaea courbaril\u0026nbsp;\u003c/em\u003e(Caesalpiniaceae)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e1875.2 grams\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e319\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eOwn data\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eAmber from Totolapa, Chiapas, Mexico.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eearly Miocene\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e†\u003cem\u003eHymenaea mexicana\u0026nbsp;\u003c/em\u003ePoinar and Brown, 2002 (Caesalpiniaceae)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e2000 grams\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e107\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eSolórzano-Kraemer et al. [29]\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eAmber from El Valle 7 Cañadas, Dominican Republic\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eearly Miocene\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e†\u003cem\u003eHymenaea protera\u0026nbsp;\u003c/em\u003ePoinar, 1991 (Caesalpiniaceae)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e1678.8 grams\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e270\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eOwn data\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eAmber from San Rafael, Dominican Republic\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eearly Miocene\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e†\u003cem\u003eHymenaea protera\u0026nbsp;\u003c/em\u003e(Caesalpiniaceae)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e523.5 grams\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e140\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eOwn data\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eAmber from Southland region of the South Island, and Otago, New Zealand\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003elate Oligocene and early Miocene\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cem\u003eAgathis\u0026nbsp;\u003c/em\u003esp.(Araucariaceae)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003ethe exact amount is unknown, estimation: 1000 to 1500 grams\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e78\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eSchmidt et al. [45]\u003c/p\u003e\n \u003cp\u003e(Alexander Schmidt, pers. comm., February 2023)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eAmber from Anglesea Coal Measures (ACM), Australia\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eearly Eocene\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e*\u003cem\u003eAgathis\u003c/em\u003e sp\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eca. 2000 grams\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e47\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eStilwell et al. [35], own data 2025\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eAmber from Macquarie Harbour Formation (MHF), Australia\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eearly Eocene\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e*\u003cem\u003eAgathis\u003c/em\u003e sp\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eca. 1500 grams\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eStilwell et al. [35], own data 2025\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eAmber from Fourtou, France\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003emiddle Cenomanian\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e†\u003cem\u003eAgathoxylon\u0026nbsp;\u003c/em\u003esp. (Araucariaceae) or †Cheirolepidiaceae\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eca. 2000 grams\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e40\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eGirard et al.\u0026nbsp;[78],\u0026nbsp;own data 2025\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eAmber from\u0026nbsp;Fouras/Bois Vert, France\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eearly Cenomanian\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e†\u003cem\u003eAgathoxylon gardoniense\u003c/em\u003e(Araucariaceae) and †Cheirolepidiaceae\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eca. 3000 grams\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e113\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eNéraudeau et al. [79], Perrichot et al.\u0026nbsp;[21], own data 2025\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eAmber from\u0026nbsp;Ile d’Aix, France\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eearly Cenomanian\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e†\u003cem\u003eAgathoxylon gardoniense\u003c/em\u003e (Araucariaceae) and †Cheirolepidiaceae\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eca. 500 grams\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eNéraudeau et al. [80], own data 2025\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eAmber from La Buzinie, France\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eearly Cenomanian\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e†\u003cem\u003eAgathoxylon gardoniense\u003c/em\u003e (Araucariaceae) and †Cheirolepidiaceae\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eca. 6000 grams\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e149\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003ePerrichot et al. [21], own data 2025\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eAmber from Salignac, France\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eearly Cenomanian\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eAraucariaceae\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eca. 400 grams\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e27\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003ePerrichot et al. [21], own data 2025\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eAmber from\u0026nbsp;Archingeay-Les Nouillers, France\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003elate Albian\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e†\u003cem\u003eAgathoxylon gardoniense\u003c/em\u003e (Araucariaceae) and †Cheirolepidiaceae\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e35000 to 40000 grams\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e1330\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003ePerrichot et al. [21], own data 2025\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eAmber from Les Renardières, France\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003elate Albian\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e†\u003cem\u003eAgathoxylon gardoniense\u003c/em\u003e (Araucariaceae) and †Cheirolepidiaceae\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e300 grams\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003ePerrichot et al. [21], own data 2025\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eAmber from\u0026nbsp;Cadeuil, France\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003elate\u0026nbsp;Albian\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e†\u003cem\u003eAgathoxylon gardoniense\u003c/em\u003e (Araucariaceae) and †Cheirolepidiaceae\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eca. 8000 grams\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e98\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eNéraudeau et al. [81], own data 2025\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eAmber from Peñacerrada, Álava, Spain\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003elate Albian (Early Cretaceous)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cem\u003eAgathis\u003c/em\u003e-like (Araucariaceae) (Chaler and Gramsimalt [82])\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e139500 grams\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e3346\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eOwn data\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eAmber from San Just, Teruel, Spain\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003elate Albian (Early Cretaceous)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cem\u003eAgathis\u003c/em\u003e-like (Araucariaceae)\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e12900 grams\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e387\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eOwn data\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eAmber from\u0026nbsp;La Hoya, Castellón, Spain\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eearly Cenomanian (Early Cretaceous)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cem\u003eAgathis\u003c/em\u003e-like (Araucariaceae)\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e5500 grams\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e11\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eOwn data\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eAmber from El Soplao, Cantabria, Spain\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003emiddle Albian (Early Cretaceous)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cem\u003eFrenelopsis\u003c/em\u003e sp. (†Cheirolepidiaceae) and other possible Cupressaceae (Menor-Salván et al. [77])\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e19937 grams\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e1600\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eOwn data\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eAmber from Arroyo de la Pascueta, Teruel, Spain\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003elate Albian (Early Cretaceous)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cem\u003eAgathis\u003c/em\u003e-like (Araucariaceae)\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e7000 grams\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e14\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eOwn data\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eAmber from\u0026nbsp;La Rodada, La Manjoya, Spain\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003elate Albian (Early Cretaceous)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cem\u003eAgathis\u003c/em\u003e-like (Araucariaceae)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e500 grams\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003ePeñalver et al. [83]\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eAmber from Ariño, Teruel, Spain\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eearly Albian (Early Cretaceous)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cem\u003eAgathis\u003c/em\u003e-like (Araucariaceae) (Álvarez-Parra et al.\u0026nbsp;[46])\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e1128 grams\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e100\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eOwn data\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eAmber from Doumanga, Congo\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003emiddle Aptian\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e†\u003cem\u003eAgathoxylon\u0026nbsp;\u003c/em\u003esp. (Araucariaceae) or †Cheirolepidiaceae\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e2550 grams\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e47\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eBouju \u0026amp; Perrichot [84], own data 2025\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":true,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"bmc-biology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"","sideBox":"Learn more about [BMC Biology](https://bmcbiol.biomedcentral.com/)","snPcode":"12915","submissionUrl":"https://submission.springernature.com/new-submission/12915/3","title":"BMC Biology","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"amber, actuotaphonomic studies, Cretaceous, Miocene, biocoenosis, taphonomy, copal, Defaunation resin","lastPublishedDoi":"10.21203/rs.3.rs-6999659/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-6999659/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eBackground\u003c/strong\u003e The genera \u003cem\u003eAgathis\u003c/em\u003e(Coniferales: Araucariaceae) and \u003cem\u003eHymenaea\u003c/em\u003e(Fabales: Fabaceae) contain resin-producing tree species that are crucial for actuotaphonomic studies. While certain Cretaceous ambers likely originated from \u003cem\u003eAgathis\u003c/em\u003e or \u003cem\u003eAgathis\u003c/em\u003e-like trees, \u003cem\u003eHymenaea\u003c/em\u003eis the primary source of many Miocene ambers. Field studies were conducted in New Caledonia and Madagascar, to collect Defaunation resin (resin produced after 1760 AD (Anno Domini)). Arthropods were collected with yellow sticky and Malaise traps in New Caledonia, Madagascar and Mexico. Cretaceous and Miocene ambers, copals (2.58 Ma to 1760 AD), and Defaunation resins from various regions were analysed to compare arthropod trapping patterns.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eResults\u003c/strong\u003e Actuotaphonomic results show lower number of arthropods trapped in \u003cem\u003eAgathis\u003c/em\u003e Defaunation resin, with a non-uniform distribution, compared to the abundant and uniformly distributed arthropods trapped in \u003cem\u003eHymenaea\u003c/em\u003eDefaunation resin. The lower number of arthropod inclusions in the trunk resin of the \u003cem\u003eAgathis\u003c/em\u003etrees is attributed to the rapid polymerisation of that resin. Under the same experimental conditions, the arthropods in \u003cem\u003eAgathis\u003c/em\u003e Defaunation resin plot far from the arthropods collected in the yellow sticky and Malaise traps, while the arthropods in \u003cem\u003eHymenaea\u003c/em\u003e Defaunation resin plot close to the arthropods in the yellow sticky traps.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusions\u003c/strong\u003e These findings confirm different resin trapping patterns between \u003cem\u003eAgathis\u003c/em\u003e and \u003cem\u003eHymenaea\u003c/em\u003e, with significant implications for interpreting the amber record. The fauna trapped by \u003cem\u003eHymenaea\u003c/em\u003e resin closely resembles the arthropod biocoenosis that live in and around the trunks, indicating autochthony and close relationship with the forest ecosystem, unlike \u003cem\u003eAgathis\u003c/em\u003eresin. These results improve our understanding of arthropod trapping biases in resin and lead us to reconsider previously proposed interpretations of Cretaceous forest biocoenoses.\u003c/p\u003e","manuscriptTitle":"Agathis vs. Hymenaea – trapping biases to interpret arthropod assemblages in ambers","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-10-25 11:59:03","doi":"10.21203/rs.3.rs-6999659/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Accepted","date":"2025-10-22T21:02:30+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-10-09T09:18:46+00:00","index":"","fulltext":""},{"type":"submitted","content":"BMC Biology","date":"2025-10-08T15:26:26+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"bmc-biology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"","sideBox":"Learn more about [BMC Biology](https://bmcbiol.biomedcentral.com/)","snPcode":"12915","submissionUrl":"https://submission.springernature.com/new-submission/12915/3","title":"BMC Biology","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"5a39c357-57cb-4524-9afc-034e6da34070","owner":[],"postedDate":"October 25th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2025-11-10T20:02:16+00:00","versionOfRecord":{"articleIdentity":"rs-6999659","link":"https://doi.org/10.1186/s12915-025-02453-y","journal":{"identity":"bmc-biology","isVorOnly":false,"title":"BMC Biology"},"publishedOn":"2025-11-07 00:00:00","publishedOnDateReadable":"November 7th, 2025"},"versionCreatedAt":"2025-10-25 11:59:03","video":"","vorDoi":"10.1186/s12915-025-02453-y","vorDoiUrl":"https://doi.org/10.1186/s12915-025-02453-y","workflowStages":[]},"version":"v1","identity":"rs-6999659","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-6999659","identity":"rs-6999659","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}