Dicynodontia

Dicynodonts were an extinct clade of mostly herbivorous therapsids, typically characterized by a toothless beak and a pair of enlarged upper tusks. They lived from the Permian through the Triassic.

Therapsida: A group of synapsids that includes mammals and their extinct close relatives. Dicynodonts belong to this broader group of mammal-line synapsids.
Dicynodont beak: A keratin-covered, toothless structure at the front of a dicynodont's jaws. The beak could crop vegetation while the tusks served other functions.
Permian: The geologic period from about 299 to 252 million years ago, ending with Earth's largest known mass extinction. Dicynodonts first diversified during this period.
Dicynodon: A genus of dicynodont therapsids from the Late Permian of southern Africa. Its name, meaning “two dog teeth,” inspired the group's name.
Karoo Supergroup: A thick sequence of sedimentary rocks in southern Africa preserving a rich record of Permian and Triassic life. Its fossil beds preserve many dicynodonts and track their changing communities.
Anomodontia: A major therapsid group whose members generally had reduced teeth and specialized herbivorous jaws. Dicynodontia is the principal lineage within this broader group.
Dicynodont tusk: An enlarged upper canine tooth found in many dicynodonts. These tusks distinguish many members of the group and may have served in display or defense.
Triassic: The geologic period from about 252 to 201 million years ago, following the Permian. Dicynodonts persisted through much of this period and vanished near its end.
Placerias: A large dicynodont genus known from the Late Triassic of North America. It shows that sizable dicynodonts survived late into the Triassic.
Lystrosaurus Assemblage Zone: A fossil-bearing interval in southern Africa named for the abundance of Lystrosaurus remains. It captures the dominance of one dicynodont after the end-Permian extinction.

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