It was the biggest sea turtle that has ever existed (although not the only one), reaching 4.5 meters in length. Despite its' size, it was no more aggressive than the modern sea turtles are, and actually lacked a hard bony shell, just as the modern leatherback turtle does. That made it vulnerable to attacks by such carnivores as Tylosaurus, as well as various Cretaceous sharks. In its own turn, Archelon probably fed on jellyfish, squid and ammonites, just as the modern sea turtles do. Unfortunately, the turtle couldn't retract its' head and flippers inside the shell - again, like the modern sea turtles. Consequently, several skeletons of Archelon, lacking flippers, were found by various scientists.
Most of Archelon skeletons are injured by Mosasaurs, or others Predator, like Xiphactinus.
In Walking With... SeriesEdit
Archelon featured in the last episode of Sea Monsters was a docile animal, as said before, and even gave Nigel Marvin a ride, until a Xiphactinus came too close for comfort and attracted several mosasaurs. Fortunately, the giant sea turtle was able to escape in the confusion and not get eaten.