Syodontinae is a group of

dinocephalia Dinocephalians (terrible heads) are a clade of large-bodied early therapsids that flourished in the Early and Middle Permian between 279.5 and 260 million years ago (Ma), but became extinct during the Capitanian mass extinction event. Dinoceph ...

therapsid Therapsida is a major group of eupelycosaurian synapsids that includes mammals, their ancestors and relatives. Many of the traits today seen as unique to mammals had their origin within early therapsids, including limbs that were oriented more ...

s. It is one of two subfamilies in the family Anteosauridae, the other being Anteosaurinae. They are known from the Middle Permian Period of what is now Russia and South Africa. One of the best known syodontines is ''

Syodon ''Syodon'' is an extinct genus of dinocephalian therapsids that lived approximately 267-260 million years ago during the middle Permian period of the Paleozoic era. These therapsids, located in Russia were initially believed to be true mammals. ...

'' from Russia. The South African form ''

Australosyodon ''Australosyodon'' is an extinct genus of dinocephalian therapsids from the middle Permian of South Africa. The first fossil was discovered in the 1980s near the village of Prince Albert Road in the Karoo region of South Africa. The genus is c ...

'', is one of the earliest known

Gondwanan Gondwana () was a large landmass, often referred to as a supercontinent, that formed during the late Neoproterozoic (about 550 million years ago) and began to break up during the Jurassic period (about 180 million years ago). The final stage ...

anteosaurs.

Description

Syodontines lack the boss on the lower jaw that characterises the related anteosaurines, and they have often been considered more primitive in this respect.

Classification

Below is a

cladogram A cladogram (from Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an evolutionary tree because it does not show how ancestors are related to d ...

showing syodontine relationships from a 2012

phylogenetic In biology, phylogenetics (; from Greek φυλή/ φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary history and relationships among or within groups o ...

study of anteosaurians:

References

Anteosaurs Guadalupian first appearances Guadalupian extinctions Prehistoric animal subfamilies Tetrapod subfamilies {{paleo-therapsid-stub