Definitions for "Ichthyosaur"
An extinct group of marine fish-like or porpoise-like reptiles abundant in Mesozoic seas.
This marine reptile lived during the middle Triassic Period and throughout the Cretaceous Period. They ranged in size from 1–10 metres in length. These reptiles had numerous sharp teeth and fed primarily on fish.
any of several marine reptiles of the Mesozoic having a body like a porpoise with dorsal and tail fins and paddle-shaped limbs
The Ichthyosaur (whose scientific name according to an in-game poster is Xenotherus ichthycanthus) is a fictitious aquatic animal in the first-person shooter computer game Half-Life. It is one of many alien species encountered in Half-Life that have been teleported to Earth from the borderworld Xen.
Keywords:  one
One of the Ichthyosaura.