Eodicynodon oosthuizeni (Barry 1974, Rubidge 1994, 25 cm in length). Eodicynodon was derived from Suminia. Many dicynodonts are known. Among them is Dicynodon (below).

This taxon had no teeth other than the large, presumeably canine tusks as the rostrum was much shorter and the temporal fenestra was much larger. Here some postcranial materials indicate a short torso and robust girdles and robust, short limbs with short digits.

The Dicynodontia includes Eodicynodon at its base. Earlier studies indicated that the dromasaur, Galeops, was the closest outgroup to the dicynodonts rather deep within the Therapsida. The large reptile tree nested anomodont (dicynodonts + Dromasauria at the very base of the Therapsida, distinct from all carnivores.

Dicynodon lacerticeps (Owen 1845) was the first dicynodont to be named. Distinct from Eodicynodon, Dicynodon had a narrower skull roof (parietals) and higher cheek bones (jugals + squamosals).

Diictodon feliceps (Owen 1876; Sullivan and Reisz 2005; Late Permian, 255mya) is known from several specimens huddled together in burrows in South Africa and China. The jugal is present, but not visible in lateral view. The premaxilla is turned down at the tip.

The origin of dicynodonts derived from Suminia and other Dromasauria.

Colobodectes cluveri (Modesto et al. 2003; Middle Permian) is considered a basal dicynodont. Here the lateral arches are restored.

Barry TH 1974. A new dicynodont ancestor from the Upper Ecca. Annals of the South African Museum 64:177-136.

Modesto S, Rubidge B, Visser I and Welman J 2003. A new basal dicynodont from the Upper Permian of South Africa. Palaeontology 46:211-223.

Owen R 1845. Report on the Reptilian Fossils of South Africa. Part I.— Description of certain fossil crania, discovered by A. G. Bain, Esq., in sandstone rocks at the south-eastern extremity of Africa, referable to different species of an extinct genus of Reptilia (Dicynodon), and indicative of a new Tribe or Sub-order of Sauria. Transactions of the Geological Society of London, 2nd Series 7:59–84.

Owen R 1876. Descriptive and illustrated catalogue of the Fossil Reptilia of South Africa in the collection of the British Museum British Museum. London.

Rubidge BS, King GM and Hancox PJ 1994. The postcranial skeleton of the earliest dicynodont synapsid Eodicynodon from the Upper Permian of South Africa. Palaeontology 37(2):397-408.

Sullivan C and Reisz R 2005. Cranial anatomy and taxonomy of the Late Permian dicynodont, Diictodon. Annals of Carnegie Museum, 74(1):45-75.

wiki/Dicynodont
wiki/Colobodectes
wiki/Dicynodon
wiki/Eodicynodon
wiki/Diictodon