Mixosaurus is an extinct genus of ichthyosaur. Fossils of Mixosaurus have been found all over the world - China, Timor, Indonesia, Italy, Spitsbergen, Svalbard, Canada, Alaska, and Nevada. It was named in 1887 by George H. Baur. The name means "Mixed Lizard", and was chosen because it appears to have been a transitional form between the eel-shaped ichthyosaurs such as Cymbospondylus and the later dolphin-shaped ichthyosaurs, such as Ichthyosaurus.
Mixosaurus was a relatively small ichthyosaur, at just 1 metre (3.3 ft) in length. It possessed a long tail with a low fin, suggesting it could have been a slow swimmer, but also possessed a dorsal fin for stability in the water. The paddle-like limbs were made up of five toes each, unlike the three toes found in later ichthyosaurs. Noteworthy, however, is that each toe had more individual bones than is usual in reptiles, and the front limbs were longer than the back limbs, both adaptations typical of later ichthyosaurs. The jaws were narrow, with several sharp teeth, that would have been ideal for catching fish.