Cranial morphology of Jonkeria truculenta (Therapsida, Dinocephalia) and a taxonomic reassessment of the family Titanosuchidae
Date
2024-06
Journal Title
Journal ISSN
Volume Title
Publisher
The Evolutionary Studies Institute
Abstract
Titanosuchidae are a group of herbivorous, long-snouted dinocephalians with definitive records known only from the middle Permian
Tapinocephalus Assemblage Zone of the Beaufort Group (Karoo Supergroup) of South Africa. Here, the taxonomy of this family is
revised; of the nine species currently recognized, only two are found to be valid: Titanosuchus ferox and Jonkeria truculenta, which can be
distinguished on the basis of appendicular proportions. Jonkeria boonstrai, J. haughtoni, J. ingens, J. parva, J. rossouwi, and J. vanderbyli are
synonymized with Jonkeria truculenta, and J. koupensis is considered a nomen dubium (Titanosuchidae indet.). Several new cranial
features are described for J. truculenta, such as pachyostosis of the prefrontals, postorbitals and parietals, and an ontogenetic series for
the species is presented.
Description
Keywords
Dinocephalia, Titanosuchidae, Beaufort Group, Tapinocephalus Assemblage Zone, taxonomy