Syodon and Australosyodon

Syodon biarmicum (Kutoroga 1838, Olson 1962; Early Tatarian, Middle Permian, 266 mya; 20cm skul; BMNH R4055l, PIN 157/2) is known from a complete skull with hooked canines and a robust jugal. Derived from a sister to P, Syodon was a terminal taxon. Kutorga's holotype was a single canine. This extraordinary Russian scientist is largely forgotten now. However, he was the first to spot the connection between the early therapsids and the mammals.

Australosyodon nyaphuli (Rubidge 1994; 20cm skull length; NMQR 3152) is a medium-sized dinocephalian with a tall, narrow skull. Thenasals are quite small and the lateral temporal fenestra is quite deep. The canines are laterally flattened. Posterior dentary teeth flattened to form a crushing surface.

Juvenile? Anteosaurus? (Kruger 2014; Kruger, Ribidge and Abdala 2017; BP/1/7074) In her PhD dissertation, Kruger wrote, "Because of its relatively large orbits, the unfused nature of its sutures, and the lack of replacement teeth in the dental alveoli, the specimen is considered to be a juvenile Anteosaurus magnificus. The juvenile Anteosaurus (BP/1/7074) manifests many features of both Syodon and Titanophoneus, it is suggested that ontogenetic growth of Anteosaurus follows Haeckel’s Law."

Here this specimen nests with Australosyodon, not Anteosaurus. Titanophoneus is a closer match to Anteosaurus.

Kruger A 2014. Ontogeny and cranial morphology of the basal carnivorous dinocephalian, Anteosaurus magnificus form the Tapinocephalus assemblage zone of the South African Karoo. PhD dissertation, U of Witwatersrand, Johannesburg.

Kruger A, Rubidge BS and Abdala F 2017. A juvenile specimen of Anteosaurus magnificus Watson, 1921 (Therapsida: Dinocephalia) from the South African Karoo, and its implications for understanding dinocephalian ontogeny, Journal of Systematic Palaeontology: http://dx.doi.org/10.1080/14772019.2016.1276106

Kutorga SS 1838. Beitrag zur Kenntnis der ‘organischen Uberreste des Kupfersandsteins am westlichen: Abhang des Ural. St. Petersburg, N. Gretsch.

Olson EC 1962. Late Permian terrestrial vertebrates, USA and USSR, Transactions of the American Philatelic Society 52(2).

Rubidge BS 1994. Australosyodon, the first primitive anteosaurid dinocephalian from the Upper Permian of Gondwana. Palaeontology 37(3):579–594.

Therapsida

Anomodontia

Galechirus - Galepus

Patranomodon

Eodicynodon - Dicynodon