Ceresiosaurus

Ceresiosaurus had the shortest skull of any known nothosaur, making it look more like a plesiosaur.1

Its flippers were very long, with many extra finger bones, just like later plesiosaurs.1

Scientists think Ceresiosaurus swam like a penguin, using its powerful tail and hips to push through the water instead of wiggling its body.1

There are two species: Ceresiosaurus calcagnii and Ceresiosaurus lanzi, which lived at slightly different times.1

The older species, C. calcagnii, had heavy, dense bones in its ribs, which helped it stay underwater like a diver's weight belt.2

The younger species, C. lanzi, had lighter bones and was probably a faster swimmer in open water.2

Ceresiosaurus lived in a warm, subtropical lagoon with many other small marine reptiles.1