Evolution of the temporal skull region
The temporal region describes the area between the orbits and occiput in the tetrapod skull. While it was ancestrally fully covered by dermal bone,
many later tetrapods distinctly reduced their dermal armor in this region, often forming different sets of temporal openings like fenestrae or emarginations. Especially in amniotes (mammals,
birds, reptiles) the configuration of these openings has been traditionally argued to be phylogenetically informative; hence, inspiring the naming of several taxa like Synapsida, Diapsida, or
However, new fossil finds, genetics, and large-scaled phylogenetic analyses raised doubts on the phylogenetic value of such openings. Instead, they may be responses to functional demands caused by the arrangement of the jaw musculature, cranial kinesis, or developmental strategy.
In this project we review the research history on the temporal skull region. Additionally, we analyze the evolutionary causes for the formation of temporal openings, especially in context of their initial evolution in early amniotes
This project is conducted as part of my doctoral thesis at the SHEP Tübingen in the lab of Prof. Dr. Madelaine Böhme, supervised by PD Dr. Ingmar Werneburg in collaboration with Yannick Pommery, Dr. David Ford, Dr. Neil Brocklehurst, and Prof. Dr. Daisuke Koyabu.
Skull of extant tuatara (Sphenodon punctatus) with two pairs of temporal fenestrae (red).
The early reptile Captorhinus aguti from the Permian of the USA, a model organism used for this project. Artist: Markus Bühler.