Developmental table of an Agamid lizard, Agama impalearis Boettger, 1874

This is the first description of the embryonic development of an agamid liz ard from North Africa, Agama impalearis. The developmental stages of only o ne species of the same family, Calotes versicolor, had been described previ ously. Two complementary studies had been per formed on this Asian species, one dealing with intra-oviductal development, the other with extra-oviduct al development. Among other iguanians, several cameleonid species and only two American iguanid species had apparently been examined. The other previo us studies dealt with some species among the Lacertidae (complete or partia l embryonic development), Scincidae, Cordylidae and Anguidae (partial embry onic development). In the present table, 42 stages have been distinguished during the embryonic development of A. impalearis. Stages 1 to 27 correspon d to intra-oviductal development including egg segmentation, gastrulation, neurulation and the beginning of organogenesis. Stages 28 to 42 describe mo rphological changes during extra-oviductal development, i.e. between egg-la ying 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 ornamenta tion which is specific. (C) 2000 Editions scientifiques et medicales Elsevi er SAS.