Evolutionary Origins of Viviparity in the Reptilia. II. Serpentes, Amphisbaenia, and Ichthyosauria

摘要: Superimposition of reproductive mode data from the literature over phylogenetic classification systems reveals that viviparity (live-bearing reproduction) has evolved on at least 35 independent occasions among Serpentes, once in Amphisbaenia, and Ichthyosauria. Of ophidian origins live-bearing mode, fourteen have occurred Colubridae, twelve Viperidae, three Hydrophiidae (used sense Smith et al., 1977), one each following groups: Boidae, Acrochordidae, Tropidophiidae, Uropeltidae, Typhlopidae, Elapidae. Previous analysis distinguished defined 45 lizards. Here, ten additional saurian are recognized basis unpublished recently published evidence, Iguanidae, two Scincidae, Agamidae, Chamaeleontidae, Anguidae, Xenosauridae, Anniellidae. As relationships clarified, further seem likely to be detected, particularly Hydrophiidae, Iguanidae. At present, however, 92 can within class Reptilia. Reptilian arisen multiple six major biogeographic regions, with a majority having Old World. Nearly 19% extant reptile species probably live-bearers, including more than 20% snakes About 71 % viviparous belong either or The discontinuous distribution reptilian families supports hypothesis selective pressures, preadaptations, constraints vary high taxonomic levels.