THE MORPHOLOGY OF THE SKULL IN NEOTENIC AND NORMAL TRITURUS VULGARIS MERIDIONALE (BOULENGER) (AMPHIBIA CAUDATA SALAMANDRIDAE)

Abstract

SUMMARY The authors provide a detailed description of the skull in neotenic Triturus vulgaris meridionalis (Boulenger) (Amphibia Caudata Salamandridae) and compare it with the morphology of normal adults. The finds are also compared with published data concerning other urodeles. Though some interesting differences are found between the skull of normal and neotenic individuals, these do not plead in favour of the general hypothesis that neoteny has had a general role in the evolution of urodeles. The authors suggest that at an early stage of urodele evolution, telescoping of developmental phases occurred as an adaptation to short seasons favourable to larval development. The cranial kinesis of Triturus vulgaris is described in detail and this supports the contention by IORDANSKY (1982), contrary to current belief, that cranial kinesis is widespread among urodeles. Some features of cranial changes at metamorphosis appear to be linked with functional requirements.