CEB Committe on Evolutionary Biology

Benjamin Otoo

Early Carboniferous tetrapod fossil 3D scan, shown on laptop

This summer I studied the postcranial anatomy of Whatcheeria. It’s an Early Carboniferous tetrapod, and important because both it’s uniquely primitive for its age and represented by lots of specimens that cover essentially the entire skeleton- almost unheard of for an early tetrapod. Despite consistently being recovered on the tetrapod stem in phylogenetic analyses, it shares a number of skeletal features with the anthracosaurs, a phylogenetically more derived Carboniferous-Permian group that are frequently considered to be amniote relatives. I’m looking forward describing these features with new phylogenetic characters and finding out if they change Whatcheeria’s phylogenetic position and our understanding of early tetrapod relationships. This is part of my research that’s broadly focused on understanding the evolutionary and ecological changes in the aftermath of the end-Devonian extinction 359 million years ago.

One nifty thing I got to do was use our new surface scanner on a collections visit to Cleveland, where they have a large collection of Early Carboniferous tetrapod fossils I examined for comparison with Whatcheeria. In addition to the usual notes, photos, and measurements, I used the scanner to generate 3D scans of specimens. Apart from being very cool, surface scanning lets me capture the surface morphology of specimens. In addition to surface detail, the scanner also captures color and the real-life size of the object. It’s also much faster than CT scanning and can scan a wider range of objects, making it useful for working with larger numbers of specimens.