biarmosuchians

Biarmosuchians are an early clade of therapsids, among the most basal lineages within Therapsida. They lived during the Middle to Late Permian, roughly 270 to 260 million years ago, with fossils found in Africa, Europe, and Asia, indicating a broad distribution across Pangaea.

Physically, biarmosuchians were small to medium-sized carnivores or insectivores. They typically had large heads relative to body size and a long, sometimes slender snout in certain taxa, with sharp canine-like teeth and varied postcanine dentition. The skull commonly features ornamentation or crests, and the cheek and jaw regions show changes that foreshadow the more mammal-like jaw mechanics of later therapsids. Their skeletons suggest a semi-sprawling gait and a range of body plans across different genera.

In evolutionary terms, biarmosuchians are considered among the earliest diverging therapsids, representing an important stage in the shift from pelycosaur-grade ancestors to more derived therapsids that would come to dominate later in the Permian. They illustrate early diversification within Therapsida and the emergence of characteristic therapsid skull and dental features that would be elaborated in subsequent lineages.

The group declined by the end of the Permian, and their lineages did not persist into the Triassic. Fossils are primarily known from Permian deposits, contributing to our understanding of early therapsid distribution and morphology across multiple regions.