Dicynodontia

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
    |--EmydopideB93
    |    |--EmydopsB93
    |    `--Myosaurus gracilis Haughton 1917M00, B93
    |--KingoriidaeB93
    |    |--Dicynodontoides parringtoni Broom 1940B93
    |    |--Kombuisia frerensis Hotton 1974M00, B93
    |    `--KingoriaB93
    |         |--K. nowacki (Huene 1942)B93
    |         `--K. recurvidens (Owen 1876)B93
    `--PristerodontiaM00
         |  i. s.: OdontocyclopsM00
         |         Pristerodon [Pristerodontidae]B93
         |           |--P. mackayi Huxley 1868B93
         |           `--P. merwevillensis (Broili & Schroeder 1935)B93
         |--Lystrosaurus Cope 1870M00, D07 [Lystrosauridae]
         |    |--L. curvatusD07
         |    |--L. declivisD07
         |    |--L. georgiD07
         |    |--L. hediniD07
         |    |--L. mccaigiD07
         |    |--L. murrayi (Huxley 1859)B93
         |    |--L. ovicepsD07
         |    |--L. platycopesD07
         |    |--L. rajurkariD07
         |    |--L. robustusD07
         |    |--L. shichanggouensisD07
         |    `--L. weidenrichiD07
         `--+--+--DinanomodonM00
            |  `--KannemeyeriiformesM00
            `--Dicynodon Owen 1845M00, D07 [Dicynodontidae]
                 |--D. acutirostris Broom 1935B93
                 |--D. bolorhinusD07
                 |--D. grimbeekiD07
                 |--D. lacerticepsM00
                 |--D. leontopsD07
                 |--D. lissopsD07
                 |--D. osborniD07
                 |--D. platecepsD07
                 |--D. traquairi (Newton 1893)B93
                 |--D. trautscholdiD07
                 |--D. trigonocephalusD07
                 |--D. turpiorD07
                 `--D. whaitsiD07
Dicynodontia incertae sedis:
  Cistecephalus Owen 1876D07
    `--C. microrhinusD07
  EmydosesM00
  Otsheria [Otsheriidae]K88
    `--O. netsvetajevi Tchudinov 1960B93
  VenyukovioideaTT05
    |  i. s.: Suminia getmanovi Ivakhnenko 1994TT05
    `--VenjukoviidaeB93
         |--Ulemica efremovi Ivakhnenko 1996TT05
         `--VenjukoviaK88
              |--V. invisa Efremov 1938B93
              `--V. prima Amalitsky 1922B93
  RobertiidaeB93
    |--Robertia broomiana Boonstra 1948B93
    `--Diictodon Owen 1876D07
         |--D. felicepsD07
         |--D. joubertii (Broom 1905)B93
         `--D. nanus (Broom 1936)B93
  AulacephalodontidaeB93
    |--Pelanomodon rubidgei Broom 1938B93
    |--Geikia elginensis Newton 1893B93
    `--AulacephalodonN85
         |--A. baini (Owen 1845)B93
         `--A. peavotiN85

*Type species of generic name indicated

References

[B93] Benton, M. J. 1993. Reptilia. In: Benton, M. J. (ed.) The Fossil Record 2 pp. 681–715. Chapman & Hall: London.

[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.