Archelon lived at a time when a shallow sea covered most of central North America. Most of the known remains have been found in South Dakota and Wyoming.

What was the habitat of the archelon?

Archelon was a huge marine turtle (Testudines) that was the size of a car. It lived in North America 74 million years ago (from the Upper Cretaceous) in the epeiric inland sea called the Western Interior Seaway. Fossils have been found in the U.S. states of Kansas and South Dakota.

When was the archelon alive?

Archelon, extinct giant sea turtle known from fossilized remains found in North American rocks of the Late Cretaceous epoch (100 million to 66 million years ago). Archelon, protected by a shell similar to that found in modern sea turtles, reached a length of about 3.5 m (12 feet).