Fossil amphibians and reptiles from the Neogene locality of Maramena (Greece), the most diverse European herpetofauna at the Miocene/Pliocene transition boundary

Abstract

Altres ajuts: CERCA Programme/Generalitat de Catalunya

We herein describe the fossil amphibians and reptiles from the Neogene (latest Miocene or earliest Pliocene; MN 13/14) locality of Maramena, in northern Greece. The herpetofauna is shown to be extremely diverse, comprising at least 30 different taxa. Amphibians include at least six urodelan (Cryptobranchidae indet., Salamandrina sp., Lissotriton sp. [Lissotriton vulgaris group], Lissotriton sp., Ommatotriton sp., and Salamandra sp.), and three anuran taxa (Latonia sp., Hyla sp., and Pelophylax sp.). Reptiles are much more speciose, being represented by two turtle (the geoemydid Mauremys aristotelica and a probable indeterminate testudinid), at least nine lizard (Agaminae indet., Lacertidae indet.,?Lacertidae indet., aff. Palaeocordylus sp.,?Scincidae indet., Anguis sp., five morphotypes of Ophisaurus, Pseudopus sp., and at least one species of Varanus), and 10 snake taxa (Scolecophidia indet., Periergophis micros gen. et sp. nov., Paraxenophis spanios gen. et sp. nov., Hierophis cf. hungaricus, another distinct "colubrine" morphotype, Natrix aff. rudabanyaensis, and another distinct species of Natrix, Naja sp., cf. Micrurus sp., and a member of the "Oriental Vipers" complex). The autapomorphic features and bizarre vertebral morphology of Periergophis micros gen. et sp. nov. and Paraxenophis spanios gen. et sp. nov. render them readily distinguishable among fossil and extant snakes. Cryptobranchids, several of the amphibian genera, scincids, Anguis, Pseudopus, and Micrurus represent totally new fossil occurrences, not only for the Greek area, but for the whole southeastern Europe. The four different types of serration within the Varanus teeth from Maramena raise questions on the taxonomic importance or the variability of this feature. The large number of distinct amphibian and reptile taxa in Maramena makes this Greek locality by far the most diverse and speciose among all European localities across the latest Miocene and earliest Pliocene. An estimation of the palaeoprecipitation value of the locality is provided. The biogeographic origins of the Maramena herpetofauna are not fully resolved, though certain of its elements were previously only known from the early and middle Miocene of Central Europe.