Actiosaurus

Actiosaurus was first described in 1883 by a scientist named Henri Sauvage.1

It was originally thought to be a dinosaur, but in 1908 scientists thought it might be an ichthyosaur, which is a marine reptile, not a dinosaur.1

Some scientists now think Actiosaurus might be a choristodere, which is another kind of reptile that lived in water.1

Actiosaurus is considered a nomen dubium, which means its fossils are too incomplete to be sure what it really is.1

The fossils of Actiosaurus are about 205 to 201 million years old, from the Rhaetian age of the Late Triassic.2