NOTHOSAURUS

genus of primitive marine reptiles found as fossils in Triassic rocks (those formed 245 to 208 million years ago) of southwestern and eastern Asia, North Africa, and especially of Europe. Nothosaurus was characterized by a slender body, long neck and tail, and long limbs. Although it was an aquatic form, the limbs were not particularly specialized for life in the water, even though webbing probably was present between the digits. In many ways, Nothosaurus and related forms, known as the nothosaurs, resembled the more successful plesiosaurs but were not ancestral to them. The palate in the nothosaurs was closed, and the air passages were separated from the food passages, an adaptation to aid feeding while in the water. Numerous pointed teeth were present along the margins of the jaws. Nothosaurus probably swam through the water and could whip its long, slender neck about in pursuit of fleeing fish. It is probable that Nothosaurus and related forms evolved from terrestrial reptiles.