What was one of the biggest marine reptiles in the Western Interior Seaway?

Answered by Jason Smith

One of the biggest marine reptiles in the Western Interior Seaway during the Late Cretaceous period was the mosasaur. These creatures were truly massive, reaching lengths of up to 50 feet long. They had long, streamlined bodies with powerful tails and flippers, allowing them to navigate through the water with ease. Mosasaurs were apex predators, meaning they were at the top of the food chain in their marine ecosystem.

To sustain their large size, mosasaurs needed to consume a significant amount of food. Paleontologists have been able to gain insights into their diet by studying the preserved remains of mosasaur stomachs. These stomach contents provide valuable information about the types of prey that mosasaurs would have targeted.

One of the most common food items found in mosasaur stomachs is fish. Fish were abundant in the Western Interior Seaway and would have been an easily accessible food source for these marine reptiles. The stomach contents often show partially digested fish bones and scales, indicating that mosasaurs would have swallowed their prey whole.

In addition to fish, mosasaurs also preyed on other marine creatures such as sharks. Fossilized shark teeth have been found in mosasaur stomachs, suggesting that they would have targeted these large predators as well. This demonstrates the ability of mosasaurs to take down formidable prey and highlights their position as top predators in their environment.

Another interesting finding is the presence of cephalopods in mosasaur stomachs. Cephalopods are a group of marine animals that include squids and octopuses. These creatures would have provided a good source of nutrition for mosasaurs due to their soft bodies and high protein content. The discovery of cephalopod beaks in mosasaur stomachs indicates that these reptiles were not picky eaters and would consume a wide variety of prey.

Perhaps the most astonishing find is the evidence of mosasaurs feeding on birds. Fossilized bird bones have been discovered in mosasaur stomachs, providing direct evidence of predation on these flying creatures. It is believed that mosasaurs would have ambushed birds as they flew close to the water’s surface, snatching them with their powerful jaws.

There have even been cases of mosasaurs preying on other mosasaurs. Fossilized mosasaur remains have been found with bite marks that match the teeth of other mosasaurs. This suggests that cannibalism was not uncommon among these reptiles, especially when other food sources may have been scarce.

Mosasaurs were incredible marine reptiles that had a diverse and varied diet. They would consume fish, sharks, cephalopods, birds, and even other mosasaurs. The discovery of preserved mosasaur stomach contents provides valuable insights into the feeding habits and ecological role of these fascinating creatures in the Western Interior Seaway.