Ichthyosaur

Ichthyosaurs are marine reptiles that descended from terrestrial ancestors. Their body shape changed over many generations. The first representatives of this group occurred over 240 million years ago during the Triassic period, and the last ones became extinct during the Cretaceous, 94 million years ago. Their streamlined body, the long and pointed snout, arms and legs that had been converted into flippers and a huge dorsal fin allowed them to become agile swimmers. They actively hunted for squid and fishes as well as other marine reptiles