Galesauridae

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Galesauridae Fossil range: late Latest Permian to Middle Triassic
Scientific classification
Kingdom: Animalia Phylum: Chordata Class: Synapsida Order: Therapsida Suborder: Cynodontia (unranked) Epicynodontia Family: Galesauridae
Genera
Cynosaurus Nanictosaurus Progalesaurus Galesaurus Thrinaxodon

Galesauridae, along with the family Thrinaxodontidae and the large clade Eucynodontia (which includes the mammals) make up the unranked taxon called Epicynodontia. Galesaurids first appeared in the very latest Permian period, just a million years (or perhaps only a thousand years) before the greatest extinction of all time, the Permian-Triassic extinction event.

Galesaurids are the most primitive of the epicynodonts. They may have resembled the basal cynodonts, such as the procynosuchids and may have descended from a procynosuchid-like ancestor, but the galesaurids were more advanced than the basal cynodonts. It is clear that, like many other epicynodonts, many galesaurids had a complete secondary palate, which allowed them to swallow food while breathing, and the dentary bone was enlarged relative to those of their ancestors. Their temporal fenestrae are much larger than those of the procynosuchids, but not as large as in more advanced epicynodonts. Their snouts are broad, rather than tall, and they may have walked erect, with the legs beneath the body like most other cynodonts.

Galesaurid fossils are found almost worldwide. They were among the survivors of the Permian-Triassic extinction event, but they became extinct in the Middle Triassic epoch, as did the therocephalians. One of the most notable genera of the family Galesauridae is Galesaurus.