Introducing a new Permian reptile: Scyllacerta creanae With a tympanic fossa on the quadrate and no lower temporal bar, Scyllacerta challenges long-standing ideas about when-and-how hearing evolved in reptiles 🦎👂 🔗 doi.org/10.1111/pala...

Scyllacerta was first discovered in the early 1990s and originally identified as a juvenile aggregation of Youngina capensis. But it was older (~257 Ma vs ~253 Ma) and from a different assemblage zone in South Africa (sus).

Even more recently, the holotype of Scyllacerta was referred to newly named Akkedops bremneri on the basis of them being from the same locality….. But they are separated by hundreds of miles and millions of years in stratigraphy…. As are the other specimens to referred to Akkedops 👀 🤷‍♂️

During my PhD, I noticed several aspects of its anatomy that didn’t match Youngina at all. So, with colleagues from Iziko Museums and University of the Witwatersrand, we CT-scanned the specimen at the European Synchrotron Radiation Facility. 🇫🇷

The scans made it immediately obvious that Scyllacerta is a distinct taxon. It has a remarkably tooth-rich palate, including teeth extending onto the braincase (!) 🦷 🧠

But the most exciting result? Scyllacerta preserves a tympanic fossa on the quadrate. This strongly suggests the presence of a tympanic (impedance-matching) ear. 👂

That question led Valentin Buffa @valentinbuffa.bsky.social and I to re-examine all non-saurian neodiapsid taxa. And we found tympanic fossae in more places than expected…. Even Youngina!

We suspect this anatomy was missed due to historical preparation techniques, especially in classic specimens like the Youngina holotype. 🔎 Newly discovered (and better-prepared) Youngina specimens all show the same feature….something that was even hinted at by Gow in the 70s….

At the same time, we see a suite of changes: • loss of the lower temporal bar • origin of a cephalic condyle • increased cranial mobility This raises the possibility that tympanic hearing and early cranial kinesis evolved together… much earlier than previously thought.