Abstract
Diagnoses are important aspects of description and identification processes, but they often do not
make it clear whether they are useful for a particular specimen. I suggest that diagnoses always
be accompanied by overt statements as to what taxonomic group the new taxon is being
compared with, and whether it is a geographically, morphologically or ecologically restricted
subset. I term the group to which the diagnosis overtly relates the reference group. Further, a
paper that provides the features that the reference group must possess has the potential for being
more broadly useful. For example, if the reference group is a subtribe but the authors explain
how to separate that subtribe from all others in the subfamily, then a user must be able to identify
only the subfamily before finding potentially useful information in the paper. I term this often
more expansive taxon the recognition group.
For 313 newly described insect genera for which diagnoses were provided, I assess the
taxonomic level and number of genera in both the reference and recognition groups. The two
groups were identical in almost half of the cases, were at the same taxonomic level but
geographically or morphologically restricted in less than 9% and at a higher taxonomic level in
the remainder. When authors explained how to identify the reference group from a larger
recognition group, the number of genera from which the new one could be differentiated
increased by a factor of more than four.
I make a series of recommendations on how diagnoses can be improved based upon
analyses of reference and recognition groups.
Key words: Best practices, ease-of-use, identification, taxonomy, insects, higher-level
classification
Author-formatted, not peer-reviewed document posted on 15/11/2024. DOI: https://doi.org/10.3897/arphapreprints.e141840
Introduction
There is increasing demand for tools to aid in the identification of the world’s biota and while
numerous modalities have been employed, at their description, new taxa are still mostly only
identifiable using traditional morphological approaches. The most common of these methods are
identification keys and diagnoses (Winston 1999; Borkent 2021; Packer 2024). Among the
almost 600 newly described genera, less than 40% were associated with a key to aid in their
identification (Packer 2024). Thus, diagnoses are critically important for biodiversity research,
especially for newly described taxa for which they may be the easiest available tool permitting
identification. Despite this, there is little advice associated with constructing diagnoses and even
their inclusion is merely a recommendation of the Code of the International Commission on
Zoological Nomenclature (ICZN 1999) which states:
“Recommendation 13A: Intent to differentiate. When describing a new nominal
taxon, an author should make clear his or her purpose to differentiate the taxon
by including with it a diagnosis, that is to say, a summary of the characters that
differentiate the new nominal taxon from related or similar taxa.”
This leaves open the question of which taxa might be “related or similar” and how
broadly those terms are to be interpreted. Both might best be understood in terms of the
characteristics an organism possesses that indicate that the diagnosis might be relevant to a
specimen at hand. This information is often not presented in a clear fashion. To improve how
diagnoses may be formulated, I define two terms: reference group and recognition group.
The reference group is the taxonomic group to which the diagnosis directly relates. For
example, if the diagnosis states: “the new genus can be differentiated from others in the subtribe”
then the reference group is the relevant subtribe. Similarly, if the diagnosis is a comparison to
only one other genus (as is commonly the case when a new genus is separated from the one to
which its species previously belonged) then the reference group is just the one genus in the
comparison.
The recognition group is the highest level in the taxonomic hierarchy for which
identifying features were provided by the author(s)—the taxonomic group to which a user must
determine that their specimen belongs for the information provided in the paper to be worth
investigating further. The recognition group is frequently at a higher taxonomic level than the
Reference
group. For example, if the diagnosis is to genera within a subtribe but elsewhere in the
paper the authors explain how to differentiate the subtribe within the subfamily but not how to
separate that subfamily from others in the family, the recognition group is the relevant subfamily,
but the reference group remains the subtribe. The reference and recognition groups are often at
the same taxonomic level but may contain different numbers of genera. For example, the
Reference
group may be a geographically, morphologically or ecologically restricted subset of a
named taxon at the same level in the hierarchy (western hemisphere Orientalidae, members of
the Filiantenninae with swollen flagellomeres or members of the Asterophagini that form galls
on rhododendron, to give some imaginary examples).
Author-formatted, not peer-reviewed document posted on 15/11/2024. DOI: https://doi.org/10.3897/arphapreprints.e141840
Inclusion of a recognition group that is more expansive than the reference group
increases the number of genera from which the new genus is discriminated from. As this is a
desirable component of new taxon descriptions, the larger the number of taxa included in the
recognition group the better. Additionally, the higher up the taxonomic hierarchy the recognition
group is, the easier it will be for users to know that the content of the paper might be relevant to
Material
in their collection because higher level taxa are easier to identify.
In this paper, I provide results of assessments of reference and recognition groups
associated with the description of new insect genera published over an 18-month period starting
in January 2021. I chose the genus level to ensure that the dataset was both tractable in size while
also including a broad range of insects. The conclusions reached, however, should be applicable
to any taxonomic rank for all groups of organisms.
Methods
In early 2022 I searched for newly described insect genera through Scopus searches using ordinal
names combined with terms such as “new gen*” or “gen* n*” filtered for the year 2021.
Searches were repeated in July and August 2022 but with 2022 as the filter. Papers dealing only
with fossil taxa were removed from the sample. The resulting papers were downloaded where
available online or through the library resources available to me and I attempted to obtain pdfs of
papers published in Zootaxa (where the largest number of new genera were described) that were
behind a paywall by contacting the senior authors and requesting a pdf (see Packer 2024 for
more details).
For each newly described genus, I looked for a section in the paper that had the word
diagnosis (or a derivative such as “diagnostic”) as a heading or subheading. Papers lacking this
were not assessed further. For each newly described genus associated with a diagnosis, I
gathered the following information in addition to standard reference data: a) the reference group
to which the diagnosis applied, b) the information that enabled a user to identify the reference
group; c) where such information was placed; d) the recognition group; e) the reason for the
difference between reference and recognition groups, when these were different, f) the number of
genera in the reference group; g) the number of genera in the recognition group and h) what
Reference
or recognition groups were implied by the paper’s title. Some of these variables require
additional explanation as follows.
Reference
and recognition groups were initially classified as given in each paper. The
categories found were—a single genus, two or more genera (including genus complex, “phyletic
series”, clade), subtribe, tribe, supertribe, subfamily, family, superfamily and order. In some
cases, it was not possible to decide at which taxonomic level the diagnosis applied and in two
cases the reference group was ecologically defined (Dorchin et al., 2021 and Gaimari et al.,
2021). These levels were simplified to four categories for visualisation due to negligeable sample
sizes for the more rarely used taxonomic levels: i) genus plus genus group, ii) subtribe to
supertribe, iii) subfamily and iv) family level and above.
When both reference and recognition groups could be detected and were different, I
searched for rationales for their differences as stated in the papers. The following categories were
found: i) geographic, ii) descriptions, iii) diagnoses, iv) keys, v) one or morphological
Author-formatted, not peer-reviewed document posted on 15/11/2024. DOI: https://doi.org/10.3897/arphapreprints.e141840
characteristics, vi) “size”, vii) “appearance”, viii) morphology-based phylogenies, ix)
“taxonomic differences”. Categories ii) through viii) could also be lumped together under the
broader category of morphological differences. For morphological differences, the number of
features given differentiating reference from recognition groups was estimated for each genus.
When data on number of genera in the reference or recognition groups were not provided
in the paper, I searched elsewhere for the information. Taxon-specific databases such as the
Orthoptera Species File (Cigliano et al. 2024) were particularly useful, but in some cases
Wikipedia or Wikispecies pages had to be consulted. All such online searches were conducted in
September 2024 and the sources of information used are indicated in Suppl. material 2 columns J
and K. I attempted to correct the numbers of genera to those that would have applied at the time
the paper was written: all new genera described after 2020 were subtracted from the totals
whenever this information could be readily located. I used the numbers given by the authors
without cross-correction as the information presented in the paper would relate to how the author
understood the group at the time and it was not possible to decide which viewpoint might be
most broadly accepted by the relevant taxonomic community. Also, it seemed likely that online
sources might not reflect the authors’ understanding of the size of the reference and recognition
groups. Online sources may be inaccurate for various reasons (for example, the wikispecies page
for Gigantometopini (Hemiptera: Miridae) does not include the genus that is imaged on the page
– Megalofaciatus, in the list of genera). Thus, I analysed group size data in two ways—first with
only information provided by the authors and second with data from additional sources also
included. When the number of genera in the reference and/or recognition group was
geographically or morphologically restricted, it was often not possible to discover how many
genera were relevant as such information is often not available unless stated by the authors.
The distribution of number of genera in reference and recognition groups had very long
right-hand tails. As averages are strongly influenced by relatively few large numerical outliers, I
often provide the median which is a more accurate reflection of differences among subcategories.
Where in the paper the information permitting separation of the reference group from the
recognition group was provided was noted. Ideally this would be in the diagnosis itself, indicated
by the term “diagnosis” in Suppl. material 2 (column I) or close by, either above it or following
the description “close”. In more extensive treatments such as in revisions of higher-level taxa,
this information might be given at the beginning of a taxonomy section and although perhaps at
some remove from a new genus’ diagnosis, its placement in such cases was considered
“sensible”. Another useful place for this information to be provided would be associated with a
key to genera if one was provided “key”. Less useful were instances where the required
information was far ahead of the diagnosis in an introduction “far” or near the end of the paper,
usually in a discussion or concluding remarks “end”.
Analyses are presented on a per-genus basis irrespective of the number of new genera
treated in the paper as it is the genus that users need to identify. Additionally, sometimes authors
used different levels in the taxonomic hierarchy for different genera described in the same paper.
For example Lee et al. (2021) had one genus as the reference group for Palumbina but seemingly
the entire subfamily for Tenupalpa (Lepidoptera: Gelechiidae: Thiotrichinae).
Author-formatted, not peer-reviewed document posted on 15/11/2024. DOI: https://doi.org/10.3897/arphapreprints.e141840
Results
Three hundred and thirteen genera were described associated with one or more diagnosis in my
sample. The papers are listed in Suppl. material 1 and the raw data associated with them in
Suppl. material 2. Below, I note in which column(s) the relevant raw data for the various
analyses can be located. I could not determine the reference and/or recognition groups
unambiguously in two papers (Goncalves and Domahovski 2021; Motamedinia et al. 2021).
Columns E and F in Suppl. material 2 show the taxonomic levels of the reference and
recognition groups as noted by the authors. The two groups were identical as originally stated in
148 cases (47.6%), were at the same taxonomic level but the former was a morphological or
geographical subset of the latter in 26 (8.4%). The reference group was one level below the
recognition group in 111 instances (35.7%, four of these were further geographically restricted),
two levels below it in 15 (4.8%), three levels in 10 (3.2%) and four levels in one (0.3%).
Reasons for differentiating the two groups were found for 160 genera (51.1% of the total,
data in Suppl. material 2 column H). More than one category of reason (as many as four) was
given for 14 genera; thus, there were 177 rationales in total. Most of these (136) were
morphological in nature (76.8% of the total number of reasons), 34 (19.2%) were geographic, 4
(2.3%) were phylogenetic and 3 (1.7%) were based upon taxonomic differences that were not
detailed.
Data for taxonomic levels based on the simplified four categories are presented in Fig. 1
for each order with at least 17 genera in the dataset as well as for the sum of all orders with fewer
data (the largest of which was Dictyoptera with nine entries). Overall, reference groups around
the tribal level were the most common (50.2% of instances) with the other three categories
ranging from 14.5% (family level and above) to 18.1% (one or more genera) (Fig. 1). The
number of cells in the table with entries less than 5 was too large for statistical analysis.
Nonetheless, it is clear that Lepidoptera and the combined data for the smaller orders both stood
out from the rest. For Lepidoptera, the percentage of reference groups at the generic level was
60%—more than twice that for the next largest value (29.4% for Orthoptera). This may reflect
the image-based identifications commonly applied to members of this group and the greater
discriminatory power expected of lepidopterists with decisions often based on wing patterns. For
the smaller orders, the use of reference groups at the family level and above was substantially
greater than in any of the larger orders (50.0% compared to an average of 11.8% among the
others). This is perhaps unsurprising given that, by definition, the smaller orders have less
diversity.
For the recognition group, the taxonomic level data range from 10.9% for genus group to
38.8% for subfamily. Again, Lepidoptera and the combination of smaller orders are outliers
requiring genus group-level identification and family or higher-level respectively for over half of
the new genera respectively (Fig. 1).
Author-formatted, not peer-reviewed document posted on 15/11/2024. DOI: https://doi.org/10.3897/arphapreprints.e141840
Fig. 1. Distribution of reference (above) and recognition (below) groups among four taxonomic
levels each expressed as a percentage ofthe total number of diagnoses provided separately for the
six major orders as well as for the minor orders combined.
0
10
20
30
40
50
60
recognition group
>=family subfamily tribe genus
0
10
20
30
40
50
60
70
80
Reference
group
%
Author-formatted, not peer-reviewed document posted on 15/11/2024. DOI: https://doi.org/10.3897/arphapreprints.e141840
The number of genera in the reference group was stated in the paper in 257 cases
(82.1%), are presented in Suppl. material 2 column J and ranged from one to 257, averaging 27.1
and with a median value of 13. When data from additional sources were included, the reference
group was given or could be estimated for 299 genera (95.5%), ranged from 1 to over 2400,
averaged 43.7 and had a median of 17.
The authors provided the number of genera in the recognition group in 156 cases (49.8%)
as shown in Suppl. material 2 column K. This number ranged from one to 265, with an average
of 41.7 and median of 25. The number of genera in the recognition group could be estimated for
an additional 138 genera (for a total of 294, 93.9%) when data from additional sources were
included. The number of genera ranged from one to ~28000 (all beetles), averaged of 476.9 and
had a median of 45.5.
The increase in number of genera in the recognition group compared to the reference
group could be estimated from the information presented by the authors for 150 genera (47.9%)
and ranged from zero to 253 with an average of 18.3 and median of zero due to the large number
of instances where the two groups were identical (91 instances - 60.7% of the genera where the
datum could be calculated). With zeros removed, the average became 45.9 and the median value
32. Again, with zeros removed the number of genera from which the new one could be
differentiated increased by an average of 8.4 times and a median of 4.1 times.
When other sources of information were included, the increase in size of the recognition
groups could be estimated in 289 cases (92.3%) and ranged from zero to almost 24000, averaged
440.7 and with a median of 9 which became 56 when zeroes were removed. Again, when
identical recognition and reference groups were removed from the data where group size(s)
estimated from extraneous information were included, discrimination of the recognition group
resulted in an average increase of 127 times more genera, with a median of five times.
When morphological features were given to separate reference and recognition groups,
the number of features requiring observation varied from 1 to 49 with an average of 12.1 and
median of 7 (Suppl. material 2 column L). One or more of the features required dissection (of
genitalia or digestive system) in 47 cases ranging in relative proportion from one out of 26
features to both of two. The average proportion of features that required dissection among all
features was 10.5%. Both sexes were required to identify the reference group in six cases and
both sexes as well as the pupa in one more. Thus for 5.3% of the genera for which the relevant
data were presented, it was seemingly not possible for a user to embark on checking the
diagnosis for the new genus unless they either had both sexes, or a juvenile stage in addition to
both sexes.
Placement of the information that permitted identification of the reference group was in
the diagnosis itself in 24 instances (14.8%), in a sensible position within the overall taxonomic
treatment in 89 (54.9%) and close to the diagnosis in 21 (13.0%) (usually immediately above it
or in a remarks section beneath the description). Less usefully, these data were given two or
more pages above the diagnosis in 21 instances (13.0%), near the end of the paper in six (4.3%)
and in a phylogenetic tree in one (0.6% - see recommendation #6 below).
Keys were available to aid in the identification of 122 of the new genera (38.6%; Suppl.
Material
2, column M). Papers lacking a key had significant differences in the taxonomic levels
of their reference and recognition groups compared to those with keys, but the patterns were not
Author-formatted, not peer-reviewed document posted on 15/11/2024. DOI: https://doi.org/10.3897/arphapreprints.e141840
simple. Reference groups without a key were disproportionately less represented at intermediate
taxonomic levels (subfamily and tribe) (χ2 = 16.7, p < 0.001) whereas recognition groups had
fewer subfamilies for those genera not made identifiable with a key compared to all other
taxonomic levels (χ2 = 27.1, p < 0.00001). The numbers of genera in reference or recognition
groups did not differ significantly whether an identification key was, or was not, provided when
based upon data provided by the authors (z = 0.75, p = 0.46 and z = 1.6, p = 0.11 respectively).
When data from extraneous sources were included, there were significantly fewer genera in both
Reference
and recognition groups in papers without a key compared to those with one (in both
cases z=2.31, p=0.021). Genera not made identifiable with a key were more likely to have the
Reference
and recognition groups identical (χ2 = 20.2, p < 0.00001), thus making the paper
describing them less useful in two ways: lacking a key and having the smallest possible
recognition group.
The taxonomic information provided in the paper’s title (Suppl. material 2 column E)
indicated the reference group precisely in 64 cases (20.8%), differed only in terms of geographic
or ecological delimitation in 95 (30.9%), indicated a higher taxonomic level in 116 (37.8%) and
a lower one in 24 (7.8%). The title reflected the recognition group in 25 cases (8.2%), differed
only in ecological or geographic delimitation in 95 (30.9%), a higher taxonomic level in 79
(25.7%) and a lower taxonomic level in 107 (34.9%). Thus, the title of the paper may be
considered misleading as to the taxonomic relevance of the information within (through over – or
understating its generality) for ~80% of the genera.
Discussion
Diagnoses are important components of the description of new taxa and their inclusion has been
recommended by the ICZN since 1930 (Rheindt et al., 2023). But how might a user decide
whether the diagnosis is relevant to a specimen they wish to identify?
I have provided a framework whereby this information might be conveyed: the reference
group being that to which the diagnosis applies directly, and the recognition group the taxon
which the user needs to be able to identify before using the more finely discriminatory
information in the publication. While these were often the same, there are two main advantages
to proscribing a recognition group that is at as-high-a taxonomic level as possible, or at least as-
high-a-level as might be reasonable depending on the audience. First, the more expansive the
recognition group the easier it will be for a user to determine whether their specimen belongs to
it or not and thereby decide that further investigation of the paper is warranted. Second, the
larger the recognition group the more likely it is that users will already have the information to
identify it. For example, if the diagnosis for the new genus compares it to only one other genus
(especially if the shared features that differentiate them from higher taxonomic levels are not
provided), the user needs to be able to identify the original genus. Precisely this situation was
found in ten instances (where entries in Suppl. material 2, columns F and G both state “1 genus”.
This does a disservice both to taxonomy and to those that use the results of taxonomic research:
such papers will rarely be cited because so much additional information is required of a user for
the paper to be readily comprehensible to them.
Author-formatted, not peer-reviewed document posted on 15/11/2024. DOI: https://doi.org/10.3897/arphapreprints.e141840
At the opposite extreme, if a new genus is diagnosed within a family but how to tell
members of that family from all others in the order is outlined, the user needs only to be able to
identify a specimen at the ordinal level for the information in the paper to be potentially useful.
A good example of this was Lôpez-Pérez and Zaragoza-Caballero’s (2021) description of two
new genera of beetles of the family Telegeusidae in which they also explain how to differentiate
the family from all other beetles. In this instance, the user can get from more than 28000 genera
to just one from a single research article (which included a global key to genera in the family).
Recognition groups at the ordinal level were found in six instances (Suppl. material 2 column H).
This approach is useful as even beginner entomologists would likely be able to recognise most
insects at this level. Recognition groups at the family level were found in 58 instances. This
might be considered the lowest level at which a useful recognition group can be defined for a
wide range of users in that keys to families within orders (either globally or geographically)
should be available to any committed entomological taxonomist.
How expansive the information associated with a new taxonomic description is should
depend on the target clientele of the paper. Braby et al. (2024) state that a diagnosis “should
provide sufficient information to allow anyone to distinguish the new species from similar or
closely related species” [italics mine]. By extension, diagnoses of genera should also allow
anyone to identify the genus, indeed, their higher taxonomic rank should make their
identification easier. Clearly these statements are too optimistic (not everyone has access to a
microscope or literature for example), but it does seem that most new genus descriptions are
aimed at an audience comprising no more than the few other taxonomic experts in the same
group. This is a pity given the increasing global interest in, and acknowledged importance of, the
world’s biota – especially given the repeated statements that the field of taxonomy is in crisis
(e.g. Löbl et al. 2023).
Of course, the title of a journal article should provide the reader with the information
required to decide whether to proceed with the text of the paper as an identification tool relevant
to specimens at hand. But in almost 40% of cases, the title suggested a broader (higher
taxonomic level) relevance than was provided, potentially wasting user’s time. This doubtless
Results
from the requirements of most journals to state the order and family that are the topic of
the paper. Loosening of that regulation so that either reference or recognition groups or both can
be provided, or overtly added, would seem useful and it would be preferable if stating what these
are is mandatory.
Some journals require a complete taxonomic breakdown for the new taxa at the
beginning of the taxonomy section. For example, the instructions to authors for the European
Journal of Taxonomy state with respect to the results “[T]this section should start with
a contextual account of the current taxonomic hierarchy of the target taxon”. However, this can
be misleading as it suggests that the subsequent information is relevant to the lowest level
provided in that hierarchy. For example, in Biscaccianti et al (2022), the taxonomic hierarchy
suggest the diagnosis might differentiate the new genus from those within its tribe, whereas it is
separated from “all other known genera” of its family, which is much more useful. In the other
direction, Chang et al. (2021) describe three new genera, each of which is diagnosed only with
respect to one other genus, yet both the title and the taxonomic hierarchy suggest that tribal level
Author-formatted, not peer-reviewed document posted on 15/11/2024. DOI: https://doi.org/10.3897/arphapreprints.e141840
differentiation might be expected and no key is provided to assist. These issues could easily be
avoided through overt statement of the reference and recognition groups.
Recommendations
Based upon the deliberations above, I provide the following eight recommendations. Although
the data upon which these ideas were generated were from newly diagnosed insect genera, I
believe they should apply to all taxa at all levels in the hierarchy, including the species level.
1. State reference and recognition groups overtly: “the diagnosis contrasts the new taxon with all
others in the subtribe Diagnostina (reference group), this subtribe can be differentiated from all
others in the family (recognition group) by….”. In some cases, there was some doubt as to
whether the authors meant what they actually said – for example if a genus is separated from all
others in its group but the paper’s title suggests that the taxa being considered are for a
geographically restricted subset of that taxon.
2. State how both groups are understood. This would be analogous to the taxon concept (Meier
2017; Packer et al. 2018). This recommendation is necessitated by the seemingly disparate ways
different authors sometimes understood the same taxon. In instances where there is taxonomic
controversy as to group membership, authors should state which classification they are using.
For example, Scheffrahn et al. (2021) and Arias et al. (2021) place the Termitidae into different
orders and Ramos and Melo (2021) and Wood et al., (2022) put closely related bees into
different families. The best way to do this would be to cite a reference that defined the group –
“sensu Melo and Gonçalves (2005) or Michener (2007) respectively for the previous example.
3. State the number of taxa that are in the reference and recognition groups. This not only
provides an additional potential check for the groups’ taxon concept but also gives the reader an
idea of the complexity of the task of separating a specimen to be identified from others in the
groups.
4. State the reference and recognitions groups in the (sub)heading to the diagnosis and start the
diagnosis with information that permits differentiation of the reference group from the
recognition group. Alternatively, provide the characteristics separating reference from
recognition groups in an obvious position, immediately above the diagnosis perhaps. It was often
necessary to search the entire paper to find out whether a recognition group could be detected
and to find the features that separate the reference group from it: why hide the information that
enables a potential citer to know whether the paper is worth further study? [Of course, authors
may have mentioned the recognition group only “in passing” as their focus would have been on a
more narrowly defined taxon.]
5. Provide information to differentiate reference from recognition groups briefly and use features
that are decisive. As with keys (Packer 2024) as well as diagnoses (Packer unpublished data)
features with exceptions or overlapping states are of limited utility as they are indecisive
although if carefully worded, especially in the context of a combination of features, they may
help exclude some taxa. Similarly, long descriptive text explaining how to identify the reference
group will be more onerous for a user to get through: perhaps only a few features in combination
will be sufficient.
Author-formatted, not peer-reviewed document posted on 15/11/2024. DOI: https://doi.org/10.3897/arphapreprints.e141840
6. Discriminatory information should be easy for a user to access. As a counterexample, to
discover the defining features to differentiate the reference group from the recognition group in
Chen et al (2021), the user must locate the characters that define the group from the phylogeny
given in a supplementary figure (where the states are not provided though character numbers
are), find the relevant matrix from among a set of supplementary tables wherein the 56 column
and 55 row data matrix is provided to locate the relevant state numbers and then look at the
character state descriptions elsewhere in the supplementary material. In this example, users must
go through three unnecessarily time-consuming steps before obtaining an answer that could
easily have been given in the body of the paper.
7. The information provided to differentiate reference from recognition groups should be as easy
to assess as possible. If the features provided include information from both sexes, then those
features will not be assessable from a single specimen or presumes users have associated the
sexes correctly. If one or more of the features listed require dissection, unless they are the only
suitable features, the information will be unnecessarily time-consuming to evaluate.
8. Be consistent with respect to the reference or recognition group being used. For example,
Crispolon et al., (2021) listed their new genus under a subtribe but in the discussion stated that it
could not be placed in a subtribe, causing some confusion for the reader.
Conclusion
Diagnoses will be made considerably more useful if authors, reviewers and editors ensure that
two simple facts are overtly provided for each new taxon: a) what group is the diagnosis directly
related to (the reference group) and b) how can that group be identified from among a broader
range of organisms that might be relatively easy for a user to distinguish (the recognition group).
Acknowledgements
I thank Thomas Onuferko and Doug Yanega for comments on an earlier draft of this manuscript
and Czarina Ortega for typing the list of references provided in Suppl, material 1. The impetus
for this paper came partly from comments received on an earlier manuscript of mine from
Wojciech Pulawski for which I remain thankful.
References
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formerly connected to the ‘old’ genus Atritomus Reitter, 1877 (Coleoptera, Mycetophagidae):
taxonomy, distribution, and description of a new genus. European Journal of Taxonomy 828: 61–
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