Anomodontia

Anomodontia is a major clade within Therapsida, the group of mammal-like reptiles that dominated terrestrial ecosystems in the Permian and early Triassic. The clade is composed primarily of herbivorous forms and includes the best-known subgroup Dicynodontia. Anomodonts first appear in the fossil record in the Permian and persisted into the Triassic, with their greatest diversity in the Permian.

Anomodonts are characterized by a beaked snout and, in many taxa, reduced or absent post-canine teeth behind the beak. Many also feature prominent tusks. Their anatomy reflects a primarily herbivorous lifestyle, with variations in body size from small to large.

The clade encompasses several lineages, the most speciose being Dicynodontia, which includes genera such as Dicynodon and Lystrosaurus. Dicynodonts were widespread and ecologically successful in Permian and Early Triassic faunas, and Lystrosaurus became one of the most common terrestrial vertebrates after the Permian mass extinction.

Phylogenetically, Anomodontia is a major branch of Therapsida, with Dicynodontia as its most derived subgroup. The sister group to Anomodontia is traditionally considered Theriodontia, which includes other therapsid lineages such as gorgonopsians and cynodonts. Relationships within Anomodontia have varied among studies, but its status as a distinct lineage of herbivorous therapsids is widely accepted.

Extinction and legacy: Anomodonts declined during the Triassic, with the later history reflecting broader faunal turnover after the Permian–Triassic extinction event. Dicynodonts disappeared by the Late Triassic, marking the end of the group’s record.