Albanerpeton is an extinct genus of salamander-like lissamphibian found in North America and Europe, first appearing in Cretaceous-aged strata. There are eight described members of the genus, and one undiagnosed species from the Paskapoo Formation, with the most recent, A. ektopistikon being described by Carrano et al.in 2022.[1] Members of the genus had a robust head and neck which likely allowed them to actively burrow, characteristic of fossorial species, and they lived in a wide range of environments. This genus of amphibian was the last of its order, surviving until the late Pliocene in southern Europe, and into the Early Pleistocene (Gelasian) of northern Italy. It likely became extinct when the region developed its present Mediterranean-type climate, having preferred one that was cold and humid.[2] The monophyly of Albanerpeton has recently been questioned[3][4]
Albanerpeton was first described by Estes and Hoffstetter in 1976. However, the genus was re-described by Gardner in 1999 after a large collection of jaws and frontals from Miocene fissure fills near La Grive-Saint-Alban in southeastern France was found.[5] When the type species was originally described, it was considered to be a salamander, despite possessing no known features that were otherwise restricted to Urodela, as its only salamander-like features were held in common with small, limbed, and non-saltatorial amphibians in general.[6] A. inexpectatum had many unique characteristics, distinct from salamanders and other amphibians (such as its feeding apparatus, dermal bones of the skull, and anterior cervical vertebrae) that Fox and Naylor suggested it be classified in its own order, Allocaudata, family, Albanerpetontidae, and genus, Albanerpeton, all of which were new at the time.[6] Seven of the eight species are restricted to the Western Interior of North America, suggesting that the evolutionary history of the genus was centered there,[7] although the presence of a sole species in France,[5] A. inexpectatum, suggests a Tertiary dispersal of an unknown species from North America into Europe. Albanerpeton jaws and frontals are the most commonly recovered Albanerpeton bones found at dig sites, but these bones exhibit many characteristics that are taxonomically and phylogenetically informative for the genus and individual species within it.[5]
The description of A. arthridion by Gardner in 1999 established a minimum age of latest Aptian for Albanerpetontidae's establishment in North America.[8] A later paper by Gardner in the same year, in which he described A. cifelli, helped fill missing information in the genus’ record during the Cretaceous period.[9] The finding and description of A. pannonicus in 2005 extended the genus’ temporal range from the middle Miocene to the early Pliocene.[10]
In 2018, Villa et al. investigated fossil herpetofauna and the palaeoenvironment in Northern Italy's town of Rivoli Veronese. The investigation supported the hypothesis that Albanerpeton favored a moist environment, and confirmed the former presence of a humid, forested landscape on Po Plain's northern side in the Gelasian, supporting the genus’ preference for humid environmental conditions, and also further extended the genus’ temporal range to the Gelasian period.[2] The discovery and description of a new Albanerpetontidae species, who is closely related to genus Albanerpeton, from the Kuwajima Formation in Japan, Shirepeton isajii, further extends the group into Asia, though the genus Albanerpeton has still only been found in North America and Europe.[3]