Jack Milligan recently visited Patagonia to study turtle fossils from the Paleocene Salamanca Formation in Chubut, Argentina, analyzing trace fossils on turtle shells. This study is ongoing, but early observations indicate that the tracemakers behind the trace fossils seen on Chelid and Pan-chelid turtle carapaces and plastrons include alligatoroids, beetles, leeches, and barnacles.

The image shows an example of a trace fossil left on a turtle fossil by a beetle, the morphology similar to Osteocallis isp.

Through this research, the trace fossils can be used to understand the taphonomic pathway of these turtles, and how the trace fossils can be used to inform paleoenvironmental conditions at different stages of taphonomy. In addition to the trace fossils, several paleopathologies were identified, many of which could have resulted from trophic interactions between the turtles and other animals.

Thanks to Dr. Juliana Sterli and Dr. Marcelo Krause for hosting this research at the MEF, this will be a very cool project!

Written by Jack Milligan