Ectothermic vertebrates from the late Middle Miocene of Gratkorn (Austria, Styria)

Abstract

In this paper, we present the ectothermic vertebrate fauna from the late Middle Miocene locality Gratkorn (Austria). In total, 2 fish, 8 amphibian and 17 reptile taxa have been described. Among them reptiles are the most abundant group. Fish remains are very rare and comprise only small- sized cyprinids (Leuciscinae indet.) and gobiids (Gobiidae indet.). Caudates are represented by a small-sized newt (Triturus sp. aff. T. vulgaris), a salamander (Salamandra sansaniensis), and a crocodile newt (Chelotriton aff. paradoxus). Anurans are documented by Rana sp., Pelophylax sp., Latonia sp., Bufotes cf. viridis ,a ndPelobates sanchizi. The most diverse and numerous ectothermic verte- brate group are scincomorph reptiles (lizards), of which more than 30 bones belonging to six taxa (Scincidae indet., Lacerta s.l. sp. 1-3, Miolacerta tenuis ,? Edlartetia sp.) have been recognised. Gecko remains (Gekkonidae indet.) are rare. Anguimorphs are represented by a large monitor lizard (Varanus sp.) and a small-size species of Ophisaurus spinari. Four snake taxa are present in Gratkorn: two "small-sized colubrins" Colubrinae sp. 1 and sp. 2, a natricine (Natricinae sp.), and a cobra (Naja sp.). Turtles are represented by two aquatic turtles (Clemmydopsis turnauensis, Chelydropsis murchisonae) and two terrestrial tortoises (Testudo cf. steinheimensis, Testudocf. kalksburgensis). The fauna of am- phibians and reptiles of Gratkorn (layer 11b) reflects a variety ofhabitats,relativelysparselyvegetatedfloodplainwithsandy soils, including short-lived ponds, streams or rivulets in the closevicinity,relativelyopenlandscapes,withadry,semi-arid climate (MAP 486±252 mm).