Amphibians, although terrestrial, are challenged by terrestrial environments because they must undergo a larval stage in water (although some complete this stage in eggs laid in a very moist environment). Reptiles are fully adapted to terrestrial life because they do not require water for development and can lay their eggs on land.
|The adjacent image is of lizard eggs.|
success of the amniotes in terrestrial environments caused the extinction
of many of the early amphibians which were not as well adapted to terrestrial
environments. Reptiles diversified into a great variety of
groups, including dinosaurs, pterosaurs, and marine reptiles, and dominated
terrestrial, aquatic, and aerial environments during much of vertebrate
history. Birds and mammals evolved from reptiles.
The groups of reptiles which have survived to modern times are crocodilians
(the largest modern reptiles), lizards, snakes, and turtles (in addition
to a few smaller groups such as amphisbaenans and tuataras). Of these groups, only turtles and snakes inhabit