Eutherocephalia
Eutherocephalia is an infraorder of therocephalian therapsids. Eutherocephalians are distinguished from the lycosuchids and scylacosaurids, two early therocephalian families. While lycosuchids and scyalosaurids became extinct by the end of the Permian period, eutherocephalians survived the Permian–Triassic extinction event. The group eventually became extinct in the Middle Triassic.
The clade Eutherocephalia contains the majority of therocephalians, yet the phylogenetic relations of the groups within it remain unclear. Eutherocephalia is supported as a true clade in many phylogenetic analyses, but the placement of groups like Akidnognathidae, Hofmeyriidae, Whaitsiidae, and Baurioidea, all of which lie within Eutherocephalia, remains debated.
The Eutherocephalians evolved several mammal-like traits through convergent evolution with the Cynodonts. Among those traits were the loss og palatine teeht and the reduction of the parietal eye. The latter organ is instrumental in thermoregulation among lizards and snakes, indicating both Eutherocephalians and Cynodonts were evolving toward a more active, homeotherm lifestyle, though the aye never fully disappeared in the Eutherocephalians.
