The Herpetological Journal

pp.99-105

Authors: Nora R. Ibargüengoytía And Victor E. Cussac

Abstract: Squamate viviparity has evolved on several occasions, and probably independently within the genus Liolaemus itself. Hypotheses about the origin of reptilian viviparity emphasize the advantage of providing an adequate thermal environment for the embryo. At the same time, high latitudes and altitudes limit the availability of heat to perform vitellogenesis and gestation. The genus Liolaemus includes both oviparous and viviparous modes of reproduction, as well as reproductive cycles with great variations in the timing of the events. In the present work maximum juvenile size, sexual dimorphism, gonadal cycle and litter size of viviparous Liolaemus elongatus were studied. Female lizards may have annual or biennial cycles, but males reproduce annually in synchronization with the female cycle. Phenotypic plasticity may be one way that allows the species to cope with environmental constraints, and may be a reproductive adaptation that Liolaemus has evolved in response to the the cold climate in the highlands of southern South America.