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

Two fossil-bearing levels at Griesbeckerzell (the central part of the North Alpine Foreland Basin; Early Badenian, Mittlere Serie of the Upper Freshwater Molasse) have produced a rich reptile fauna that includes a large number of snakes, i.e. Grisbeckerzell lb (OSM E, 15.0–14.9 Ma): Boidae: Python sp.; Colubridae: “Coluber” cf. caspioides; Vipendae: Vipera sp. (“oriental vipers” group) or Daboia sp.; Griesbeckerzell la (beginning of unit OSM F, 14.77 Ma): Boidae: Bavarioboa aff. hermi, cf. Bavarioboa sp., Python sp.; Colubridae: “Coluber” cf. caspioides, Coluber hungaricus, “Coluber” sp., Texasophis cf. meint, Natrix sp.; Elapidae: Micrurus cf. gallicus; Viperidae: Vipera sp. (“Oriental vipers” group), Vipera sp. (“European vipers” group; “Vipera aspis complex”). The Miocene Climatic Optimum (MCO) is documented in central Europe by the presence of highly thermophilous reptile taxa, including Python sp., which is the most thermophilous reptile known from the European Neogene. The presence of Pytho... RÉSUMÉ Serpents de Griesbeckerzell (Langhien, Badénien inférieur), Bassin de l'avant-pays nord-alpin (Allemagne). Commentaires sur l'évolution des faunes de serpents en Europe centrale pendant l'Optimum Climatique du Miocène. Deux niveaux fossilifères de Griesbeckerzell (partie centrale du Bassin de la Molasse du Sud de l'Allemagne, Badénien inférieur, Mittlere Serie de la Molasse d'eau douce supérieure) ont livré une riche faune de reptiles qui contient un grand nombre de serpents: Griesbeckerzell 1b (OSME, 15,0–14,9 Ma): Boidae: Python sp.; Colubridae: «Coluber» cf. caspioides; Viperidae: Vipera sp. (groupe des «vipères orientales») ou Daboia sp.; Griesbeckerzell 1a (début de l'unité biostratigraphique OSM F, 14,77 Ma): Boidae: Bavarioboa aff. hermi, cf. Bavarioboa sp., Python sp.; Colubridae: «Coluber» cf. caspioides, Coluber hungaricus, «Coluber» sp., Texasophis cf. meini, Natrix sp.; Elapidae: Micrurus cf. gallicus; Viperidae: Vipera sp. (groupe des «vipères orientales»), Vipera sp. (groupe des «vipè...

Two fossiliferous karstic fissures from the Mokrá-Western Quarry, MWQ (1/2001 Turtle Joint; 2/2003 Reptile Joint) provided a diverse vertebrate fauna from the early Miocene (Burdigalian, MN 4) including squamates. The rather warm climatic conditions during the Miocene Thermal Maximum (17.8-17.7 Ma) enabled dispersal of thermophilic lizards and snakes throughout Central Europe. In total, ten major clades have been identified in MWQ localities, including: Lacertidae (Lacertidae indet., Lacertidae tooth morphotype 1 and 2); Amphisbaenia (Amphisbaenia indet.); ? Scincoidea (? Scincoidea indet.); Anguidae (Pseudopus laurillardi (Lartet, 1851), Pseudopus sp., Ophisaurus sp., and Anguinae indet.); Varanidae (Varanus mokrensisIvanov, Klembara, Ruta & Böhme, 2018); Boidae (Bavarioboa cf. hermiSzyndlar & Schleich, 1993); Pythonidae (Python sp.); Colubridae (Colubridae gen. et sp. indet., Coluber [s.l.] sp., and “Colubrinae” indet., type 1), Natricidae (Natrix sp. and “Natricinae” indet.); Viperidae (Viperinae [‘Oriental vipers' group], Vipera sp. [‘European vipers' group]); and Elapidae (Elapidae gen. et sp. indet.). Python sp. from the MWQ represents the first known occurrence of this most thermophilic Neogene squamate taxon within the area of Central Paratethys and we assume that MAT did not fall below 18-19 °C in the vicinity of this locality during the late Burdigalian stage. These humid subtropical to paratropical climatic conditions, also documented by several full-aquatic and semi-aquatic amphibians and reptiles, were suitable for the occurrence of other thermophilic lizard and snake taxa reported from MWQ, including Varanus mokrensis, Pseudopus laurillardi, Bavarioboa, large Elapidae and ‘Oriental vipers'.

We here describe new remains of amphibians and reptiles from the early Miocene (MN 4) of two different Greek localities, Aliveri and Karydia. The newly described material consists of urodelans, alytids, indeterminate anurans, turtles, crocodylians, lacertids, indeterminate scincomorphs, anguids, colubrids, viperids, and indeterminate snakes. The presence of the frog Latonia cf. gigantea in Greece is documented for the first time. Additionally, the presence of viperids in Aliveri implies a much wider distribution for these snakes during the early Miocene of Europe. Of special interest is the presence of a peculiar colubrid that seems to possess a hitherto unknown vertebral structure, which is herein defined as the ‘paracentral ridge’. Although incomplete, the new material has important taxonomic and biogeographic implications, as it enhances our understanding of southeastern European herpetofaunas from the early Miocene, a time period that was characterised by major dispersal and extinction events and climatic change that affected the whole continent.