Stuck in the mud: experimental taphonomy and computed tomography demonstrate the critical role of sediment in three-dimensional carcass stabilization during early fossil diagenesis - TIFF stack data

Exceptionally preserved fossils provide critical information on the
morphology and ecology of extinct organisms, but their formation remains
poorly understood. Experimental taphonomy has produced critical insights
that allow us to better understand preservation biases, but they typically
do not reflect realistic depositional environments, employ destructive
sampling, and are restricted to a two-dimensional setting. Here, we
utilize micro-computed tomography to non-invasively visualize the process
of decay of carcasses of the branchiopod Triops longicaudatus for a year
of post-burial decay. The earliest stages of post-burial diagenesis are
dynamic and produce marked differences in relative density within each of
the experimental replicates affecting both the carcass and the surrounding
sediment. After 64 weeks, specimens are still detectable as
three-dimensional voids that capture the body in life position and
external morphological features. Sediment plays a critical role in carcass
stabilization and the resulting voids provide sites for mineral
precipitation needed for exceptional three-dimensional fossilization.