Ichthyosaurs (Greek for "fish lizard" - or ichthys meaning "fish" and sauros meaning "lizard") are large marine reptiles. Various books and resources will vary on the size of which an Ichthyosaur could grow but from 1m (3ft) of the smaller species to 20m (65ft) of the largest Ichthyosaurs of the Triassic and early Jurassic is a common theory.

Ichthyosaurs looked cross between a dolphin and a shark. This is whats called ‘convergent evolution’, when different organisms come to resemble each other due to similar habitat and/or lifestyle. The Jaw of Ichthyosaur were very long, slim and pointed - similar to a dolphin’s beak, only more exaggerated. A predatory species Ichthyosaurs had many small, sharp teeth and fed on fish and squid.