Skull of the neotenic salamandrid amphibianTriturus alpestris and abbreviated development in the Tertiary Salamandridae

The skull of neotenic individuals of the Alpine Newt Triturus alpestris from the locality Drakolimni (Greece) is described on the basis of models made from magnified serial frontal sections. In order to recognize features associated with neoteny and paedomorphosis, the results were compared with normal development of contemporary Triturus and of other Caudata. The neotenic larvae from Greece correspond to advanced stages of metamorphosis in normal development of Triturus alpestris. Comparison with salamandrids from the Tertiary of Europe in which the hyobranchial skeleton was preserved, namely Brachycormus noachicus, Chelotriton paradoxus, and Palaeopleurodeles hauffi, revealed that both latter taxa were completely metamorphosed adults anatomically similar to their contemporary relatives Tylototriton, Echinotriton, and Pleurodeles, whereas Brachycormus, though apparently related to Chelotriton, was a neotenic amphibian. This is suggested by its incompletely metamorphosed but ossified hyobranchial skeleton. © 1996 Wiley-Liss, Inc.