Nothosaur means 'false lizard'.
Nothosaurs were a primitive group of marine reptiles. They are known from the middle to late Triassic (245-200 million years ago), and were predators, feeding on fish and shellfish. They had many sharp teeth for this purpose.
They were elongate animals with long necks, and nostrils located just in front of the eyes. Like the other groups of euryapsids they breathed air but spent most of their time in the water.
The limbs were shortened, but not highly modified for swimming. The feet were paddle-shaped, and were probably webbed.
They probably swam with the lateral undulating motion seen in modern aquatic lizards and crocodiles, mainly using the tail rather the feet for propulsion.
Nothosaurs ranged in size from less than 1m to more than 4m.
Nothosaurs were probably egg-layers, and would have had to climb onto the land to lay their eggs, much like modern turtles and crocodiles. They were able to walk on land, but spent much of their time hunting in the water.
Nothosaurs were closely related to the plesiosaurs, and it is thought that they may have evolved into plesiosaurs, although there is little evidence for this. They might simply have been sister-groups.
Author: Rachel Jennings
Last updated: 22/11/2005
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