Duration of Incubation of Sceloporus undulatus Eggs at Constant Temperature

Abstract

Since the retention of eggs in the oviduct must have been a key factor in the evolution of viviparity in reptiles, hatching times of S. undulatus eggs under varying external conditions were studied. S. undulatus eggs hatch over a relatively narrow temperature range with a lower limit between 20-25.degree. C and an upper one in > 35.degree. C. The implications of this are discussed in relation to other reports.