''Phthinosuchus'' is an extinct

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

of therapsids from the

Middle Permian The Guadalupian is the second and middle series/epoch of the Permian. The Guadalupian was preceded by the Cisuralian and followed by the Lopingian. It is named after the Guadalupe Mountains of New Mexico and Texas, and dates between 272.95 ± 0. ...

of Russia. ''Phthinosuchus'' is the sole member of the family Phthinosuchidae. ''Phthinosuchus'' may have been one of the most primitive therapsids, meaning that its ancestors may have branched off early from the main therapsid line.

Discovery

''Phthinosuchus'' was named in 1954 by

Ivan Yefremov Ivan Antonovich (Antipovich) Yefremov, sometimes Efremov (; 23 April 1908 – 5 October 1972) was a Soviet paleontologist, science-fiction author and social thinker. He founded taphonomy, the study of fossilization patterns. Biography He ...

. It is currently only known from the back of the skull, as the front of the skull was lost after description. Two species, ''P. discors'' and ''P. horissiaki'', have been described.

Description

''Phthinosuchus'' was 1.5 m (5 ft) long with a 20 cm skull, and looked much like the

Sphenacodontids Sphenacodontidae (Greek: "wedge point tooth family") is an extinct family of sphenacodontoid synapsids. Small to large, advanced, carnivorous, Late Pennsylvanian to middle Permian "pelycosaurs". The most recent one, ''Dimetrodon angelensis'', is ...

, such as ''

Dimetrodon ''Dimetrodon'' ( or ; ) is an extinct genus of sphenacodontid synapsid that lived during the Cisuralian (Early Permian) Epoch (geology), epoch of the Permian period, around 295–272 million years ago. With most species measuring long and ...

'' and ''

Sphenacodon ''Sphenacodon'' (meaning "wedge point tooth") is an extinct genus of synapsid that lived from about 300 to about 280 million years ago (Ma) during the Late Carboniferous and Early Permian periods. Like the closely related ''Dimetrodon'', ''Sphena ...

''. Its

temporal fenestra Temporal fenestrae are openings in the temporal region of the skull of some amniotes, behind the orbit (eye socket). These openings have historically been used to track the evolution and affinities of reptiles. Temporal fenestrae are commonly (al ...

e were larger than those of the Sphenacodontids. Its jaw was slender, unlike other predatory therapsids, but like the other early therapsids, it was probably sprawling and

carnivorous A carnivore , or meat-eater (Latin, ''caro'', genitive ''carnis'', meaning meat or "flesh" and ''vorare'' meaning "to devour"), is an animal or plant whose nutrition and energy requirements are met by consumption of animal tissues (mainly mu ...

Classification

''Phthinosuchus'' is a member of the suborder

Phthinosuchia Phthinosuchia is an extinct group of therapsids including two poorly known species, ''Phthinosuchus discors'' and ''Phthinosaurus borrisiaki'', from the Middle Permian of Russia. ''Phthinthosuchus'' is known a partial crushed skull and ''Phthinos ...

, which was made specifically for ''Phthinosuchus'' given that it did not fit into any other suborder.

References

Dinocephalia Prehistoric therapsid genera Permian synapsids of Europe Fossil taxa described in 1954 Taxa named by Ivan Yefremov {{paleo-therapsid-stub

Discovery

Description

Classification

See also

References