Nectosaurus was a member of a group of marine reptiles known as thalattosaurs, characterized by their long, paddle-like tails, and short legs with independently movable digits.
Discovery and Naming
Nectosaurus is known from fragmentary remains. The holotype, UCMP 9124, is an incomplete skeleton including vertebrae, a humerus, coracoid, ulna, radius, partial skull, and mandibles.
Although a 2001 analysis considered it a close relative of Xinpusaurus and Paralonectes because it was interpreted as having an upward-curving maxilla, further inquiry has shown that this was mistaken.