Pantosaurus

Pantosaurus had a very long neck with between 35 and 40 neck bones, called cervical vertebrae. These bones were almost as long as they were wide, which helped make the neck flexible.3

The name Pantosaurus was originally 'Parasaurus', but that name was already used for another animal, so scientists changed it.1

Pantosaurus lived in the Sundance Sea, a shallow ocean that covered parts of Wyoming millions of years ago.1

Scientists think Pantosaurus might have given birth to live young, not laid eggs, because it lived in the water.2

The front flippers of Pantosaurus were special: the radius bone was much longer and broader than the ulna, which helped it steer in the water.3

A fossil of a baby ichthyosaur (a different marine reptile) was found inside a Pantosaurus stomach, showing it ate other marine reptiles.1