Tapinocephalidae Temporal range: Middle Permian, 268–260 Ma |
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Mounted skeleton of Moschops capensis. The skeleton is displayed at the American Museum of Natural History | |
Scientific classification | |
Kingdom: | Animalia |
Phylum: | Chordata |
Order: | Therapsida |
Suborder: | †Dinocephalia |
Clade: | †Tapinocephalia |
Family: |
†Tapinocephalidae Lydekker, 1890 |
Subgroups | |
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Tapinocephalidae was an advanced family of tapinocephalians.It is defined as the clade containing Ulemosaurus, Tapinocaninus, and the Tapinocephalinae They are known from both Russia and South Africa. In all probability, the Tapinocephalidae had a worldwide (Pangean) distribution.They flourished briefly during the Wordian and Capitanian ages, radiating into several lineages, existing simultaneously, and differing mainly in details of the skull and, to an even lesser degree, the skeleton. It is not clear how such similar animals could each find their own ecological niche, but such was obviously the case. There is a parallel here with the hadrosaur and ceratopsian dinosaurs of the Late Cretaceous. The cause of their abrupt extinction is not clear, since other smaller animals, and even the pareiasaurs, were not affected. Quite probably, like the extinction of the late megafauna, a number of factors were involved.
The body is deep and capacious, allowing for a developed herbivore gut. The shoulders are much higher than the pelvic region, so that the back slopes, giraffe-fashion, from neck to tail. This seems to imply that they fed on vegetation of about a meter or more from the ground. The limbs are heavy, with sturdy forelegs that sprawled out to the sides, while the longer hind legs were placed directly under the hips (the dicynodonts had the same posture). The feet are broad and short.
The tapinocephalid skull is massively constructed, and either long-snouted (e.g. Struthiocephalus) or high and short (e.g. Moschops). Very often the top of the head is rounded, and the bones of the forehead are elevated into a sort of dome or boss, in the middle of which is a large pineal opening. In some specimens this boss is of only moderate thickness, while in others it has become greatly thickened into a huge mass of bone (pachyostosis). It has been suggested that these animals engaged in intra-specific head-butting behavior, presumably for territory or mates. A similar thickening of the skull occurs in pachycephalosaurian ("boneheaded") dinosaurs, and it is speculated that all of these animals practiced head-butting behavior like modern goats and bighorn sheep, or Late Eocene titanotheres.