54-1 Evaluating how museum storage affects microbial communities from a Late Pleistocene fossil cave deposit

Session: New Approaches to Old Fossil Collections

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Abstract:

Fossils continue to go through taphonomic processes in museum collections. To examine the role that biofilms play in degradation and conservation, we examined the microbial colonies from a Late Pleistocene (~12,000 years old) cave deposit in Wyandot, OH. Sheriden Cave was excavated in the 1990s and over 41,000 bones and associated matrix have been stored since then at the Cleveland Museum of Natural History. Sediment samples excavated at the cave in 1997 and 2024 were sent for microbiome DNA sequencing (16S/ITS Amplicon Sequencing). We compared the diversity of bacteria and fungus between the present-day cave and those that persist in the museum collection. 

In the museum sample, 17 bacteria were identified to the genus level and include bacteria commonly found in soil aiding in decomposition, nutrient cycling and plant growth. The bacterial community in the modern cave sample is more diverse, with 286 bacteria identified to the genus level. Of those, only two overlap with the museum sample, Agromyces cerinus and Psychrobacillus psychrodurans, which are both found in soils in cold environments. The majority of the bacteria in the cave now are cold-tolerant decomposers, common in soil. In the modern cave sample, 36 fungi were identified to the genus level and two were identified in the museum sample. The majority of the fungi detected in the cave are keratin decomposers that live in soils and many are often associated with caves and cold environments. Geomyces auratus, a keratin decomposer commonly found in caves, was one of only two fungi present in both samples.  

The microbial colonies in the museum collection have decreased in diversity over time, however bacteria and fungi from the cave environment are still present in the museum samples collected in 1997. The museum colonies are also distinct from those that are currently present in the cave, indicating that the colony has changed over time. Additional analyses on other fossils from the museum collection indicate different microbial colonies, demonstrating that the microbiome persists after collection and is unique based on burial environment. Specimens from museum collections can be incorporated into taphonomic research to examine continued degradation and these studies are critical for fossil conservation and evaluating appropriate specimens for molecular analyses. 

Geological Society of America Abstracts with Program. Vol. 57, No. 6, 2025

doi: 10.1130/abs/2025AM-9910

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