Tapinocephalians

Tapinocephalians are an extinct group of therapsids within the larger clade Dinocephalia, dating to the Middle and Late Permian. Fossils are primarily from the Karoo Basin of southern Africa, though related forms have been reported in other regions. They represent some of the earliest large-bodied therapsids and occupied ecological roles that followed earlier pelycosaurs, contributing to Permian terrestrial ecosystems.

Anatomically, many tapinocephalians exhibit pachyostotic, or thickened, skulls, a feature that gave rise to their name meaning "thick-headed." They were generally large and robust with heavy limbs supporting a graviportal stance. Their dentition suggests herbivory or omnivory, with broad postcanine teeth and reduced canines in several forms. The best-known member is Moschops capensis, a heavily built, domed-headed herbivore.

Ecologically, they occupied low-browsing to grazing niches in Permian environments. The thick skulls found in many species are thought to have been used for display, intraspecific combat, or other social interactions, though direct evidence remains limited. They coexisted with predatory therapsids and other Permian vertebrates and faced ecological pressures that contributed to their decline in the Late Permian.

Dispersed mainly in the Karoo, tapinocephalians are an important source of information about early therapsid evolution and Permian terrestrial ecosystems. They ultimately disappeared by the end of the Permian mass extinction, along with many other dinocephalians, marking a major turnover in prehistoric faunas.