Albanerpetontidae

The Albanerpetontidae (also spelled Albanerpetidae and Albanerpetonidae) are an extinct family of small amphibians, native to the Northern Hemisphere during the Mesozoic and Cenozoic. The only members of the order Allocaudata, they are thought to be allied with living amphibians belonging to Lissamphibia. Despite a superficially salamander-like bodyform, their anatomy is strongly divergent from modern amphibians in numerous aspects. The fossil record of albanerpetontids spans over 160 million years from the Middle Jurassic to the beginning of the Pleistocene, about 2.13–2 million years ago.

== History of research == left|thumb|Holotype fossil of Celtedens|Celtedens megacephalus from Italy The earliest specimen of an albanerpetontid to be discovered was that of Celtedens megacephalus from the Early Cretaceous (Albian) Pietraroja Plattenkalk of Italy, described by Oronzio Gabriele Costa in 1864, and originally placed in the genus Triton, a junior synonym of the salamander genus Triturus. Jaw elements of albanerpetontids from the Cretaceous of North America were assigned to the salamander genus Prosiren by Richard Estes in 1969, erecting the family Prosirenidae to accommodate the genus. Prosiren was originally described by Coleman J. Goin and Walter Auffenberg in 1958, based on vertebrae found in Cretaceous aged deposits in Texas. Albanerpeton, the type genus of the family was first named by Estes and Robert Hoffstetter in 1976 for the species of A. inexpectatum described from a large number of jaws and frontal bones from a Miocene aged fissure fill deposit near Saint-Alban-de-Roche in France, and was initially classified as a salamander, and placed in the family Prosirenidae alongside Prosiren due to the morphological similarity with the jaw fragments attributed to Prosiren by Estes (1969). Richard Fox and Bruce Naylor in 1982 realised that Albanerpeton was not a salamander, noting that the holotype vertebra of Prosiren was different to those of albanerpetontids, concluding that Albanerpeton was "well isolated from salamanders" and that it "seems no nearer phyletically to any other known amphibians, from Devonian to Recent" erecting the family Albanerpetontidae and the order Allocaudata to accommodate it.