Mixosaurus

Mixosaurus was a small, common and cosmopolitan Triassic ichthyosaur. It was only about a meter in length. Fossils are known from Alaska, Canada, China, Timor, Indonesia, Italy, Nevada, New Zealand, Spitsbergen, and Svalbard. Thus it lived in the Tethys Sea but also ventured further afield.
"Mixosaurus" seems to have been a transitional form between the more primitive eel-shaped icthyosaurs such as "Cymbospondylus" and the more advanced Shatsasaurs and Euichthyosaurs (the latter including the familiar dolphin- or porpoise-shaped icthyosaurs).