These were Mesozoic reptiles with bat-like wings supported by arms and
long thin “fingers” (Pl. 42). The pterosaurs were well adapted to life
in the air, and their light-weight bodies and wide skin-covered wings
enabled them to soar or glide for great distances. The earliest known
pterosaurs were found in lower Triassic rocks, and the group became
extinct by the end of the Cretaceous. During this time certain of these
creatures attained a wingspread of as much as 27 feet, but their bodies
were small and light.