Kryostega

Abstract: A new temnospondyl, Kryostega collinsoni, gen. et sp. nov., is described on the basis of a large snout fragment from the Triassic upper Fremouw Formation of Antarctica. K. collinsoni is characterized by greatly enlarged teeth of the transvomerine and parachoanal tooth rows, a reduced transvomerine tooth row, as well as a distinct process on the palatal surface of the premaxilla. Although key palatal and tabular features are not preserved, the shape and position of the external naris, choana, and anterior palatal vacuity suggest that K. collinsoni may be allied to the Heylerosauridae or basal Mastodonsauridae. The discovery of K. collinsoni in the upper Fremouw is surprising, given that Triassic vertebrates from Antarctica are typically considered a subset of coeval taxa from the Karoo Basin of South Africa. Based on its unique occurrence in Antarctica, K. collinsoni suggests that high latitude Triassic tetrapods had a more restricted geographic distribution than previously considered. Biostratigr...