Anteosaurians

Anteosaurians, also called anteosaurids, are an extinct group of carnivorous therapsids that lived during the Middle to Late Permian period, roughly between 270 and 254 million years ago. They are part of the larger therapsid lineage that gave rise to mammals, and they are especially associated with the group Dinocephalia. The best-known genus is Anteosaurus, which helps define the size and appearance of the group. Fossils are mainly known from fossils of South Africa, with additional fragmentary remains helping to place the group within Permian therapsid communities.

Anatomy and adaptations of anteosaurians suggest robust, large-bodied predatory animals. They possessed elongated skulls and strong jaws with prominent canine-form teeth, indicating a diet of other vertebrates. Their skulls often show thickened bone and reinforced regions around the snout and jaw joints, adaptations that may have helped withstand stresses from powerful biting. Limbs were sturdy, consistent with a terrestrial, pursuit-or ambush-predator lifestyle. The presence of skull ornamentation or bosses in some members has led to hypotheses about display or intraspecific combat, though exact social behavior remains uncertain.

Ecology and evolution: Anteosaurians occupied high trophic positions in Middle to Late Permian ecosystems, competing with other predatory therapsids. They are typically placed within Dinocephalia, a diverse and early branch of therapsids, and their evolutionary trajectory reflects the broader diversification and later decline of large Permian predators as ecosystems changed approaching the end-Permian mass extinction.

See also: Therapsida, Dinocephalia, Anteosaurus.