Western Interior Seaway Creatures

Visitors can examine the fossils of a giant turtle or see a dramatic chase scene where a plesiosaur is in pursuit of a prehistoric diving bird.

Western interior seaway creatures. Other marine life included sharks such as squalicorax cretoxyrhina and the giant shellfish eating ptychodus mortoni believed to be 10 metres 33 ft long. It lived on both sides of the western interior seaway and was an opportunistic apex predator in the coastal regions of eastern north america. Mosasaurus continued to be the dominant genus in the seaway until the end of the navesinkan age during the closure of the cretaceous.

The western interior seaway is gone but not forgotten this mass of ocean fossils was found in montana which used to be covered by a gigantic body of water. Wilson44691 wikimedia commons. The western interior seaway was a shallow sea filled with abundant marine life.

They couldn t swim into the western interior seaway so their bones were not preserved as fossils here. Opinion remains divided as to whether these two populations represent separate species. Interior seaway denizens included predatory marine reptiles such as plesiosaurs and mosasaurs that grew up to 18 metres 59 ft long.

And advanced bony fish including pachyrhizodus enchodus and also the massive 5 metre 16 ft long xiphactinus a. The western interior seaway would have covered the badlands in the late cretaceous when dinosaurs were roaming the earth. However no dinosaurs appear in the rocks within badlands national park.