A new salamandrid amphibian from the Middle Miocene of Hungary and its phylogenetic relationships

摘要

A fossil salamandrid, Carpathotriton matraensis gen. et sp. nov., from the Astaracian (Middle Miocene, MN 7) localities of Matraszolos 1 and 2 (Northern Hungary, Nograd County) is described. Within newts, Carpathotriton is diagnosed by a combination of primitive and derived characters including a premaxillary-frontal contact, a well-developed fronto-squamosal arch, low supraorbital crest and weak sculpture on the frontal surface. Referred material comprises abundant cranial, vertebral and appendicular skeletal elements that exhibit limited morphological variation of mainly allometric nature. The dentary of Carpathotriton is unique in displaying a prominent dental parapet with an extremely short tooth row and a relatively long toothless posterior ramus. The quadrate is provided with an extuberant anterolateral process that may be a homoplasy with some members of the Tylototriton group. Trunk vertebrae of Carpathotriton have extremely high neural spines with some enlargement on their dorsal margin similar to some Recent Eastern Asiatic salaman-drids and the Oligocene newt Archaeotriton. The available fossil record suggests that Carpathotriton never extended into the western Paratethys area, but might have had a wider distribution in the central and eastern Paratethys region, surviving up to late Astaracian times (MN 7 + 8). Taphonomic setting of the Matraszolos localities indicates that Carpathotriton matraensis was closely associated with aquatic environments.