Albanerpeton

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. 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. 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. although the presence of a sole species in France, 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. == Evolutionary history ==

The oldest species of Albanerpeton as usually defined are known from the late Early Cretaceous of North America. During the Late Cretaceous, Albanerpeton was widespread in North America, as well as in Europe (and was present in Asia if remains from the Khodzhakul Formation in Uzbekistan are included). The youngest remains of the species in North America are known from the Paskapoo Formation in Canada, dating to the Paleocene. == Ecology ==

Albanerpeton is suggested to have had a preference for moist environments. Albanerpetontids are proposed to have been sit-and wait predators that fed on invertebrates via the use of a ballistic tongue similar to that used by chameleons and plethodontid salamanders. == Description ==

Albanerpeton are distinct from frogs, salamanders, and caecilians, forming their own family of Lissamphibia, Albanerpetontidae. Membership of species in the family is determined by diagnostic character states of the frontals and premaxillary synapomorphies, both of which can be used to further diagnose less inclusive clades in the genus. These less inclusive clades are the gracile-snouted clade and robust-snouted clade, made up of three and four species respectively though only three of the robust-snouted clade have been fully described. The gracile-snouted clade is defined by a triangular to slit-shaped suprapalatal pit. The robust-snouted clade is defined by a robust premaxillae, a short pars dorsalis that is sutured dorsally with the nasal, a short premaxillary lateral process on the maxilla, and an internasal process on frontals that are both narrow and similar to spines. Diagnostic characteristics of the genus itself include characteristics of the teeth and skull. Dentition Albanerpeton teeth are about one-third of the distance from the anterior end of the tooth row, and these are markedly larger than other nearby teeth. Additionally, the dorsal edge of the dental boundary is curved on its lingual side. Features of the reconstructed skull consist of a robust, box-like unit composed of coossification of the parasphenoid, otic capsules, and occipital elements with no trace of fusion or sutural points of contact among these components. Additionally, the anterior three-quarters of the dorsal surface is open, but the furthest posterior portion, tectum synoticum, is fused. The ventral surface of Albanerpeton neurocrania are fully ossified, solid bone. The neurocranium of Albanerpeton is in contact dorsally with paired parietals, forming the roof of the brain cavity while contacting laterally with the squamosal. Overall, the robust construct of ''Albanerpeton's'' neurocranium is consistent with the theory that the genus was fossorial in nature, as the thickened and strengthened skull would have lent itself to burrowing. Albanerpeton have ossified antotic pillars which sit in front of the otic capsules. Additionally, there are a pair of small, robust bony pedestals that are located ventrolaterally in front of the otic capsules, which likely served to brace the neurocranium against the palatal region and suspensorium. In Albanerpeton, the otic capsules themselves are moderately inflated with a large, rhomboid-shaped fenestra vestibuli present on both capsules. These fenestrae can be used to imply the presence of middle ear ossicles in Albanerpeton. Albanerpeton had well-developed semicircular canals with a modestly developed ventral auditory region as well. ==Classification==

Current accepted species: Genus Albanerpeton Estes & Hoffstetter 1976 • Albanerpeton arthridion Fox & Naylor 1982 Early Cretaceous, United States • Albanerpeton ektopistikon Carrano et al. 2022 Early Cretaceous, North America • Clade "Gracile-snouted" • Albanerpeton gracilis Gardner 2000 Late Cretaceous, North America • Albanerpeton cifellii Gardner 1999 Late Cretaceous, United States • Albanerpeton galaktion Fox & Naylor 1982 Late Cretaceous, North America • Clade "Robust-snouted" • Albanerpeton nexuosus Estes 1981 Late Cretaceous, North America • Albanerpeton pannonicus Venczel & Gardner 2005 Latest Miocene-Early Pleistocene Hungary, Italy • Albanerpeton inexpectatum Estes & Hoffstetter 1976 Early Oligocene-Late Miocene, Europe The genus Albanerpeton is part of the family Albanerpetontidae which is part of the order Allocaudata within superorder Batrachia and class Amphibia. Members of genus Albanerpeton are considered to be Lissamphibia who are distinct in character from frogs, salamanders, and caecilians. In 2018, a closely related species, named Shirepeton isajii, was discovered and described in the Kuwajima Formation of Japan. While it is closely related to members of Albanerpeton, it does not fall within the clade. Cladogram from Venczel and Gardner (2005): }} In 2020 it was found that Albanerpeton is paraphyletic with respect to Shirerpeton and Yaksha, and it has been suggested that Albanerpeton be restricted to the Cenozoic species, with the Cretaceous species being given separate genera. Cladogram from Daza et al. (2020) Finally, with the description of Albanerpeton ektopistikon by Carrano et al. (2022), based on the data matrix from the 2018 description of Shirepeton isajii, also recovered Albanerpeton as a paraphyletic genus, further separated than in Daza et al., (2020). Instead of restricting Albanerpeton, they provisionally suggested to include Shirerpeton and Wesserpeton into the genus, turning their type species into A. isajii and A. evansae, respectively, though they also suggested that the genus could be split into separate genera. Cladogram from Carrano et al. (2022): ==References==