A new nothosaurid taxon from the Middle Triassic of Carinthia, Austria

Abstract Two recently excavated specimens of a medium-sized (up to 115 cm long) new nothosaurid taxon are described from a Middle Triassic locality in the Gailtal Alps (Austroalpine Drau Range) of Carinthia. The holotype is a complete and articulated specimen exposed in dorsal view. The referred specimen, also prepared in dorsal view, lacks the skull and is slightly smaller in overall body size. The new taxon shows an exclusive combination of morphological characters. It shares with nothosaurs the large upper temporal openings and anterolaterally expanded corners of the clavicle. Lariosaur affinities are the large number of carpalia and the configuration of the sacral region. Similarities with ceresiosaurs are the increased height of neural spines in the posterior neck and anterior trunk region, pending additionally the distinctiveness of ceresiosaurs and lariosaurs. Further on, its skull morphology, as far as sutures are discernible, shows a rectangular prefrontal that extends from the anteromedial orbital margin to the posterolateral margin of the external naris, which is a rather rare shape in nothosaurids. The morphology of the humerus and ulna as well as limb ratios are considered as autapomorphies, and a new taxon, Carinthiasaurus kandutschi gen. et sp. nov. is erected. Its phylogenetic relationships are however not tested due to the unclear status of Ceresiosaurus and the general ambiguous phylogenetic relationships within Nothosauridae, both awaiting a thorough revision.