Western Interior Seaway Fish

Modern traces of the western interior seaway.

Western interior seaway fish. And advanced bony fish including pachyrhizodus enchodus and also the massive 5 metre 16 ft long xiphactinus a. Although the appearance of mosasaurus in the western interior seaway marked a complete restructuring of marine communities centered around it there were still many fauna that coexisted with mosasaurus. Plesiosaurs are rare in the formation and were therefore likely uncommon in the western interior seaway at the time.

It existed at its fullest extent from the mid late cretaceous period. Fish species in the western interior seaway from wikipedia the free encyclopedia the western interior seaway was a large inland sea that started to expand in the early cretaceous period though geological evidence suggests it started to expand in the late jurassic period. Opinion remains divided as to whether these two populations represent separate species.

Although mosasaurs were solitary animals it s possible that mothers may have lived in groups to protect their young from sharks and giant predatory fish. The western interior seaway was also home to xiphactinus another fish i worked on the genus larger at 18 feet long than any known bony fish. It was a shallow sea with diverse marine life including predatory marine reptiles such as mosasaurs growing up to 18 meters long ichthyosaurs and plesiosaurs.

Interior seaway denizens included predatory marine reptiles such as plesiosaurs and mosasaurs that grew up to 18 metres 59 ft long. Specimens become much more numerous in the pierre shale situated above the chalk. They were fast swimmers unlike the elasmosaurs that used their long necks to catch fish.

This specimen is on display at the university of kansas natural history museum in lawrence. It lived on both sides of the western interior seaway and was an opportunistic apex predator in the coastal regions of eastern north america. Mosasaurs would have lived in these waters.

Mostly xiphactinus looks like a normal fish but with jutting pencil like teeth that could make the impressionable think twice about swimming in the ocean. The western interior seaway was a shallow sea filled with abundant marine life. Other marine life included sharks such as squalicorax cretoxyrhina and the giant shellfish eating ptychodus mortoni believed to be 10 metres 33 ft long.