Rethinking the Evolution of Temporal Fenestrae in Turtles: An Interactive Application for Comparative Anatomy and Phylogenetics

The question of turtle origins is among the oldest and most debated problems in vertebrate systematics. A key factor in this debate is the pattern of temporal fenestration in the skull, which has long been central to amniote evolutionary hypotheses. Recently, there has been robust evidence supporting turtles as having evolved within the diapsid radiation, which includes all other living reptiles. This requires that the anapsid skull in turtles is secondarily derived. ‘Transitional’ fossils that support this theory were elusive until the Middle Permian reptile Eunotosaurus africanus was re-examined using computed tomography (CT) in 2015. Eunotosaurus exhibits features that help reconcile the gap between turtles and other reptiles, but how it does so is still misunderstood. This misconception is attributed to the complexity of the evolutionary concepts involved and a need for more intuitive visuals describing the complex architecture of the Eunotosaurus skull. This thesis communicates the importance of Eunotosaurus to the study of turtle origins through a novel digital reconstruction and a 3D interactive web application. The first of its kind, this reconstruction utilizes best practices for restoring a fossil’s antemortem shape. It is then implemented in an application focused on contextualizing this taxon in the ‘tree of life.’ This application provides a valuable learning resource for students and investigators as it contributes to virtual paleontology, evolutionary science pedagogy, and functional morphology