New Sclerocephalus species and temnospondyl braincase evolution

The late Paleozoic temnospondyl Sclerocephalus formed an
aquatic top predator in various Central European lakes of the Late
Carboniferous and early Permian. Despite hundreds of specimens spanning a
wide range of sizes, knowledge of the endocranium (braincase and
palatoquadrate) remained very insufficient
in Sclerocephalus and other stereospondylomorphs,
because even large skulls had unossified endocrania. A new specimen from a
stratigraphically ancient deposit is recognized as representing a new
taxon, S. concordiae n. sp., and reveals a completely
ossified endocranium. The sphenethmoid was completely ossified from the
basisphenoid to the anterior ethmoid region, co-ossified with the
parasphenoid, and the basipterygoid joint was fully established. The
pterygoid bears an a slender, S-shaped epipterygoid, which formed a robust
pillar lateral to the braincase. The massive stapes was firmly sutured to
the parasphenoid. In the temnospondyl endocranium, character evolution
involved various changes in the epipterygoid region, which evolved
distinct morphologies in each of the major clades.