Albanerpetontid amphibians from the Late Cretaceous (Santonian) of Iharkút, Hungary, with remarks on regional differences in Late Cretaceous Laurasian amphibian assemblages

Since its discovery in 2000, the Iharkút fossil locality in the Upper Cretaceous (Santonian) Csehbánya Formation of western Hungary has yielded a taxonomically diverse assemblage of terrestrial and freshwater vertebrates that continue to provide insights into the diversity, paleobiogeography, and paleoecology of Late Cretaceous vertebrates in Europe. Albanerpetontidae, an extinct group of superficially salamander-like amphibians that were widespread across Laurasia during the latter part of the Mesozoic, are represented at Iharkút by 16 fragmentary jaws. Here we describe and figure these specimens as Albanerpetontidae genus and species indeterminate. Based on the age of the Iharkút locality, several premaxillary features, the known distribution (late Early Cretaceous – late Pliocene) of the type genus Albanerpeton, and an unusually large dentary specimen, we suggest that the Iharkút albanerpetontid may pertain to a previously unrecognized species of Albanerpeton, but verification of that must await the recovery of more diagnostically informative specimens, such as frontals and more nearly complete premaxillae. The Iharkút lissamphibian assemblage contains a mixture of taxa with Laurasian (the albanerpetontid and a discoglossid anuran) and Gondwanan (a neobatrachian anuran) affinities. Intriguing higher level differences are evident among Late Cretaceous Laurasian assemblages; for example, urodeles are scarce or absent (as at Iharkút) in Europe, whereas albanerpetontids are scarce in Middle Asia.

A new species of the side-necked turtle Foxemys (Pelomedusoides: Bothremydidae) from the Late Cretaceous of Hungary and the historical biogeography of the Bothremydini

The continental deposits of the Upper Cretaceous (Santonian) Csehbánya Formation of the Bakony Mountains in Hungary yielded abundant remains of a bothremydid side-necked turtle, which are attributed to a new species of the genus Foxemys, Foxemys trabanti. F. trabanti shows strong affinities with the European monophyletic group Foxemydina owing to the absence of pits in the upper and lower triturating surfaces, the exclusion of the jugal from the triturating surface, the separation of the Eustachian tube and the stapes by a narrow fissure, the presence of deep and narrow fossa pterygoidei, the partially closed foramen jugulare posterius and the pentagonal shape of the basisphenoid in ventral view. Among the Foxemydina the bothremydid from Iharkút is more closely related to F. mechinorum than to Polysternon provinciale from the Early Campanian of France, mainly because of the position of the occipital condyle relative to the mandibular condyles of the quadrate. The new remains represent the only record of the Foxemydina outside of Western Europe and provide the earliest known occurrence of this endemic, freshwater group in the former Mediterranean Basin. The historical biogeography of the tribe Bothremydini is investigated and a hypothesis of migration from Africa to North America via the high-latitude Thulean route is put forward.