POST-COLLECTION TAPHONOMY: A CAUTIONARY TALE FROM A WORKING DISSERTATION COLLECTION

Taphonomy in invertebrate paleontology is the study of the post-mortem history of organisms. For fossils, that post-mortem history must include what occurs after collection, including after a collection of fossils is analyzed. Processing fossils can add human-induced changes to fossil material such as breakage and even writing labels. After analysis, the fate of fossil collections, especially large dissertation and thesis collections, is dependent on whether or not the collections are properly curated and stored over time. A rare accidental experiment to test the extent of damage to an average dissertation collection lacking proper curation and storage has recently been performed on a dissertation collection that was rescued from being discarded by the original collector.

The collection of approximately 29,000 mollusk specimens (of which over 26,000 were bivalves) from the Rushmere and Morgart’s Beach members of the Yorktown was left in the care of the doctoral candidate’s institution in 1999 with the understanding that although it would be used for student projects, it would be kept intact. It was moved several times, eventually spending a decade in an unheated storage facility in southwestern Virginia, before finally being retrieved in 2016. The collection showed obvious signs of damage, including evidence of rodent activity, sample bags that contained specimens from more than one sample, and unlabeled specimens of one species rolling loose in a beer flat tray. To test the hypothesis that the retrieved collection was statistically distinct from the collection in 1999, the bivalves from samples from one locality were reprocessed by recounting the number of bivalve specimens in each sample for each species, just as was done with the original samples. Multivariate analysis and testing were used to determine whether or not the recovered samples were degraded enough that a worker who did not know about the damage would mistakenly believe that the data from 1999 and 2016 were drawn from different underlying paleocommunities.