Sealed condition induces lower fossilization potential revealed by taphonomic experiment

Understanding how remains become fossils is not a trivial process, taphonomic experiments provide important insights in this process by simulating the burial environment with modern organisms. A sealed (closed) system of high-pressure simulator has been widely used, while the unsealed condition before diagenesis is universal. Therefore, it is not fidelity to simulate the deep-water (high-pressure) environment with a closed system. The authors developed an automatic deep-water equipment ABYSSOURCE which could simulate both open and closed system. Based on ABYSSOURCE, a normal shrimp Neocaridina denticulata was applied to explore the difference between these two systems under 10±0.1 MPa (1000±10 meters in depth). This experiment focused on the decay process which is crucial to fossilization. Here we show, under the open condition, the decay rate of the sample shrimp is slower than closed one, and its preservation potential is better. A possible reason was that microbes multiplied faster in the closed system and degrade the remains stronger. These results suggested that sealed condition has not a positive effect on fossilization. By solving the challenge of material exchange in the deep-water chamber under constant pressure (±0.1 MPa), this paper provides a novel method for high-fidelity simulation of fossilization.