Dicynodontia

Mounted skeleton of Lystrosaurus murrayi in the Muséum national d'histoire naturelle, Paris, photographed by FunkMonk.

Belongs within: Eutherapsida.
Contains: Kannemeyeriiformes.

The Dicynodontia are a group of herbivorous synapsids known from the the Late Permian to the Cretaceous, though they did not survive past the Late Triassic outside Australia. At their peak, they were the world's dominant herbivores. One genus, Lystrosaurus, included the most abundant terrestrial vertebrates in the earliest Triassic immediately following the end-Permian mass extinction. The name 'dicynodont' refers to the pair of large tusks that were generally the only teeth in their beaked jaws.

Synapomorphies (from Kemp 1988): Zygomatic arch dorsally displaced; dentaries fused at symphysis; articular surface of lower jaw sloping posteroventrally; horn developed on the jaws; intramandibular fenestra present; premaxillary secondary palate present.

<==Dicynodontia
    |--Kombuisia M00
    |--Myosaurus M00
    `--Pristerodontia M00
         |  i. s.: Odontocyclops M00
         |--Lystrosaurus Cope 1870 M00, D07 [Lystrosauridae]
         |    |--L. curvatus D07
         |    |--L. declivis D07
         |    |--L. georgi D07
         |    |--L. hedini D07
         |    |--L. mccaigi D07
         |    |--L. murrayi M00
         |    |--L. oviceps D07
         |    |--L. platycopes D07
         |    |--L. rajurkari D07
         |    |--L. robustus D07
         |    |--L. shichanggouensis D07
         |    `--L. weidenrichi D07
         `--+--+--Dinanomodon M00
            |  `--Kannemeyeriiformes M00
            `--Dicynodon Owen 1845 M00, D07 [Dicynodontidae]
                 |--D. bolorhinus D07
                 |--D. grimbeeki D07
                 |--D. lacerticeps M00
                 |--D. leontops D07
                 |--D. lissops D07
                 |--D. osborni D07
                 |--D. plateceps D07
                 |--D. trautscholdi D07
                 |--D. trigonocephalus D07
                 |--D. turpior D07
                 `--D. whaitsi D07

Dicynodontia incertae sedis:
  Cistecephalus Owen 1876 D07
    `--C. microrhinus D07
  Emydoses M00
  Otsheria K88
  Venyukovioidea TT05
    |  i. s.: Suminia getmanovi Ivakhnenko 1994 TT05
    `--Venyukoviidae TT05
         |--Ulemica efremovi Ivakhnenko 1996 TT05
         `--Venjukovia K88
  Aulacocephalodon peavoti N85
  Diictodon Owen 1876 D07
    `--E. feliceps D07

*Type species of generic name indicated

REFERENCES

[D07] Dixon, D. 2007. The Complete Illustrated Encyclopedia of Dinosaurs & Prehistoric Creatures. Hermes House: London.

[K88] Kemp, T. S. 1988. Interrelationships of the Synapsida. In: Benton, M. J. (ed.) The Phylogeny and Classification of the Tetrapods vol. 2. Mammals pp. 1–22. Clarendon Press: Oxford.

[M00] Maisch, M. W. 2000. Observations on Karoo and Gondwana vertebrates. Part 2: A new skull-reconstruction of Stahleckeria potens von Huene, 1935 (Dicynodontia, Middle Triassic) and a reconstruction of kannemeyeriiform phylogeny. Neues Jahrbuch für Geologie und Paläontologie Abhandlungen 220 (1): 127–152.

[N85] Norman, D. 1985 (reprinted 2000). The Illustrated Encyclopedia of Dinosaurs. Salamander Books: London.

[TT05] Tverdokhlebov, V. P., G. I. Tverdokhlebova, A. V. Minikh, M. V. Surkov & M. J. Benton. 2005. Upper Permian vertebrates and their sedimentological context in the South Urals, Russia. Earth-Science Reviews 69: 27–77.

Last updated: 24 August 2018.