What is Therocephalia?
{{taxobox | fossil_range = Middle [[Permian]] to Middle [[Triassic]] | name = Therocephalia | image = Ictidosuchoides intermedium, Wrexham Museum.JPG | image_width = 245px | image_caption = Skull of a therocephalian in the [[Wrexham]] Museum, Wales | regnum = [[Animal]]ia | classis = [[Synapsida]] | ordo = [[Therapsida]] | unranked subordo = [[Theriodont]]ia | infraordo = '''Theriocephalia''' }} '''Therocephalia''' ('beast-heads') are an extinct group of [[theriodont]]s. They lived from the middle [[Permian]] into the [[Triassic]] 265—245 million years ago, about 20 million years. The therocephalians are named after their large skulls. Their skulls, with the structure of their teeth, suggest that they were successful [[carnivore]]s. Like other non-mammalian [[therapsid]]s, therocephalians are sometimes described as [[mammal-like reptile]]s. In fact Therocephalia is the group most closely related to the [[cynodont]]s, which gave rise to the [[mammal]]s. This relationship shows in a variety of anatomical features, possibly including [[whisker]]s and [[hair]]. There remain many unanswered questions about the [[phylogeny]], [[anatomy]], and [[physiology]] of therocephalians. The fossils of therocephalians are numerous in the [[Karoo]] of [[South Africa]], but have also been found in [[Russia]], [[China]], and [[Antarctica]]. Early therocephalian fossils discovered in Middle Permian deposits of South Africa support a [[Gondwana]]n origin for the group, which seems to have spread quickly throughout the world. Although almost every therocephalian lineage ended during the great [[Permian–Triassic extinction event]], a few representatives of the subgroup (called Eutherocephalia) survived into the early Triassic and continued to diversify. However, the last therocephalians became extinct by the early middle Triassic. The reasons for their extinction are not known. [[Category:Theriodonts]]