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An illustration of two Pristerognathus

Therocephalia ("beast-head") is a suborder of carnivorous therapsids from the Permian and Triassic periods.


Therocephalians had broad jaw muscles and reduced phalanges much like modern mammals. Most examples were likely endothermic and carnivorous, though some genera may have been herbivores instead.[1]

It is possible that some therocephalians may have been at least partially aquatic.[2]


Therocephalia is the sister group to Cynodontia, which includes all modern mammals. Both groups survived the Permian-Triassic mass extinction, but the therocephalians only persisted for a short time into the Triassic, while the cynodonts continued to diversify.[3]

Below is a cladogram modified from a paper published by Adam K. Huttenlocker in 2014, showing the position of Therocephalia within the therapsids.[4]


Biarmosuchus tener

Titanophoneus potens




Charassognathus gracilis

Dvinia prima

Procynosuchus delaharpeae

Epicynodontia →


Lycosuchus vanderrieti


Ictidosaurus angusticeps

Scylacosaurus sclateri

Alopecodon priscus

Pardosuchus whaitsi

Glanosuchus macrops

Pristerognathus polyodon


Scylacosuchus orenburgensis

Perplexisaurus foveatus


Chthonosaurus velocidens

NHCC LB36, 38 (Unnamed Zambian chthonosaurid)


Annatherapsidus petri

USNM PAL412421 (from Cistecephalus AZ]])

Akidnognathus parvus

Promoschorhynchus platyrhinus

Olivierosuchus parringtoni

Euchambersia mirabilis

Cerdops burgheri

Moschorhinus kitchingi


SAM-PK-K8516 (from Cistecephalus AZ]])

Hofmeyria atavus

Ictidostoma hemburyi

Mirotenthes digitipes


SAM-PK-K10990, K10984 (from Tropidostoma AZ)

Ictidochampsa platyceps

Viatkosuchus sumini

Moschowhaitsia vjuschkovi

Theriognathus microps


Ictidosuchops rubidgei


Ictidosuchus primaevus

Ictidosuchoides longiceps


Regisaurus jacobi

Urumchia lii


NHCC LB44 (Unnamed Zambian karenitid)

Karenites ornamentatus


Lycideops longiceps

Choerosaurus dejageri

Tetracynodon tenuis

Tetracynodon darti

Scaloposaurus constrictus


Ericiolacerta parva

Silphedosuchus orenburgensis

Nothogomphodon danilovi


Hazhenia concava

Ordosiodon youngi


Bauria cynops

Antecosuchus ochevi

Microgomphodon oligocynus

Traversodontoides wangwuensis

In popular cultureEdit

A group of unspecified therocephalians appeared in the third episode of the 2005 BBC documentary Walking with Monsters, stalking a herd of Lystrosaurus. In this series, they are depicted as being venomous. Although this feature was speculation, some therocephalian fossils show that such an ability may have been possible for certain species.

Venomous therocephalians also appeared in an episode of the ITV science fiction series Primeval.


  1. Ivakhnenko, M.F. (2011). "Permian and Triassic therocephals (Eutherapsida) of Eastern Europe". Paleontological Journal 45 (9): 981–1144. doi:10.1134/S0031030111090012.
  2. Tatarinov, L.P. (1994). "On the preservation of rudimentary rostral tubular complex of crossopterygians in theriodonts and on possible development of the electroreceptor systems in some members of this group". Doklady Akademii Nauk 338 (2): 278–281.
  3. Huttenlocker, A.K.; Sidor, C.A.; and Smith, R.M.H. (2011). "A new specimen of Promoschorhynchus (Therapsida: Therocephalia: Akidnognathidae) from the Lower Triassic of South Africa and its implications for theriodont survivorship across the Permo-Triassic boundary". Journal of Vertebrate Paleontology 31 (2): 405–421. doi:10.1080/02724634.2011.546720.
  4. Huttenlocker, A. K. (2014). "Body Size Reductions in Nonmammalian Eutheriodont Therapsids (Synapsida) during the End-Permian Mass Extinction". PLoS ONE 9 (2): e87553. doi:10.1371/journal.pone.0087553.