A new stereospondylomorph, Korkonterpeton kalnense gen. et sp. nov., from lower Permian of the Czech Krkonoše Piedmont Basin and a redescription of Intasuchus silvicola from the lower Permian of Russia (Temnospondyli, Amphibia)

A new temnospondyl, Korkonterpeton kalnense gen. et sp. nov., is described on the basis of an almost complete specimen from the lover Permian Prosecne Formation of the Czech Krkonose Piedmont Basin. The exceptional preservation of the holotype allows a detailed description of the cranial and postcranial characters: Korkonterpeton kalnense gen. et sp. nov. is characterized by the presence of vomerine fangs located anteriorly to the posterior choana, much longer than wide tabulars – as long as the supratemporals, a deeply concave posterior margin of the skull table, extraordinarily elongated exoccipitals, anteriorly widened pterygoids and a parasphenoid cultriform process swollen at its mid-length. In order to clarify the relationship between this new taxon and Intasuchus silvicola Konzhukova, 1956 from the lower Permian (late Kungurian) of the Russian Inta Basin, the latter is also redescribed here: Intasuchus silvicola exhibits a lacrimal entering the septomaxilla, a widened jugal, a posterolaterally widened interpterygoid vacuity, a subtemporal window elongated anteriorly up to the anterior orbital region, an elongated basipterygoid ramus which is as long as the orbit width, a vomer with a parachoanal tooth row, and an ectopterygoid of about the same length as the palatine. The description of Korkonterpeton kalnense gen. et sp. nov. and the revision of Intasuchus silvicola complete our knowledge on the origin and evolution of early stereospondylomorph temnospondyls during the lower Permian.