Table de développement embryonnaire d'un lézard agamidé, Agama impalearis Boettger, 1874

Abstract

This is the first description of the embryonic development of an agamid lizard from North Africa, Agama impalearis. The developmental stages of only one species of the same family, Calotes versicolor, had been described previously. Two complementary studies had been performed on this Asian species, one dealing with intra-oviductal development, the other with extra-oviductal development. Among other iguanians, several cameleonid species and only two American iguanid species had apparently been examined. The other previous studies dealt with some species among the Lacertidae (complete or partial embryonic development), Scincidae, Cordylidae and Anguidae (partial embryonic development). In the present table, 42 stages have been distinguished during the embryonic development of A. impalearis. Stages 1 to 27 correspond to intra-oviductal development including egg segmentation, gastrulation, neurulation and the beginning of organogenesis. Stages 28 to 42 describe morphological changes during extra-oviductal development, i.e. between egg-laying and hatching, and correspond to the continuation of the organogenesis. Although data in other groups are still incomplete, a comparison of the A. impalearis table with that of other lizards reveals a great homogeneity of embryonic development in these reptiles, except for the external ornamentation which is specific.