Microposaurus was a genus of temnospondyl

Temnospondyli

Temnospondyli is a diverse order of small to giant tetrapods—often considered primitive amphibians—that flourished worldwide during the Carboniferous, Permian, and Triassic periods. A few species continued into the Cretaceous. Fossils have been found on every continent...

 of the Trematosauridae

Trematosauridae

Trematosauridae are a family of large temnospondyl amphibians with many members. They first appeared during the Olenekian stage of the Early Triassic, and existed up until around the Carnian stage of the Late Triassic, although by then they were very rare...

 family. Fossils are present from the Cynognathus Assemblage Zone

Cynognathus Assemblage Zone

The Cynognathus Assemblage Zone is a geological stratum and a faunal zone of the Beaufort Group, of the South African Karoo. The name refers to Cynognathus, a genus of eucynodontian mammal-like reptile, whose fossils have been found in that structure....

 of the Beaufort Group

Beaufort Group

The Beaufort Group is the third of the main subdivisions of the Karoo Supergroup of geological strata in Southern Africa. It follows conformably after the Ecca Group and consists essentially of sandstones and shales, deposited in the Karoo Basin from the Middle Permian to the early part of the...

 (part of the Karoo Supergroup

Karoo Supergroup

The Karoo Supergroup is the largest stratigraphic unit in Southern Africa, covering almost two thirds of the present land surface, including central Cape Province, almost all of Orange Free State, western Natal, much of south-east Transvaal, Zambia, Zimbabwe and Malawi...

) in South Africa

South Africa

The Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...

 and date back to the Anisian stage

Anisian

In the geologic timescale, the Anisian is the lower stage or earliest age of the Middle Triassic series or epoch and lasted from 245 million years ago until 237 million years ago, approximately...

 of the Middle Triassic

Middle Triassic

In the geologic timescale, the Middle Triassic is the second of three epochs of the Triassic period or the middle of three series in which the Triassic system is divided. It spans the time between 245 ± 1.5 Ma and 228 ± 2 Ma...

. A mandible from the Lower Anisian Mukheiris Formation in Jordan

Jordan

Jordan , officially the Hashemite Kingdom of Jordan , Al-Mamlaka al-Urduniyya al-Hashemiyya) is a kingdom on the East Bank of the River Jordan. The country borders Saudi Arabia to the east and south-east, Iraq to the north-east, Syria to the north and the West Bank and Israel to the west, sharing...

 shares many similarities with the genus, including a similarly sized Meckelian fenestra

Meckelian groove

The Meckelian groove is an opening in the medial surface of the mandible which exposes the Meckelian cartilage....

on the inner surface of the lower jaw, teeth with sharp edges, and large fangs in the upper jaw.