The Tylosaurus is a large species of Mosasaur from the Western Interior Sea of North America during the Late Cretaceous Period that appeared in the film Fantasia.
Several Tylosaurus appear swimming in the coastal ocean in a group, surfacing to gasp for air. Late on in the scene, one of these top predators of the sea catches a Pteranodon by the head as it skims the water's surface, fishing for squid and fish.
- The Tylosaurus depicted in Fantasia had spikes on its neck and back region, features the real animal did not sport. However, this makes sense for the time as the scientists who discovered the Tylosaurus first thought that it had spines down its back, but it was discovered later on that it had a smooth back.
- Tylosaurus was also shown via skin impressions from related mosasaurs to have a tail fluke similar to a shark's.
- Mosasaurs' closest living relatives are monitor lizards such as the Komodo dragon and the related Gila monster.
- Unlike modern lizards, mosasaurs were found to be warm-blooded, as evidenced by studies in 2016.
- The scene in which the Tylosaurus seizes a Pteranodon out of the air may have been inspired by a famous painting by Czech paleo-artist Zdenek Burian, which depicts a Tylosaurus leaping out of the sea after a Pteranodon. The spikes on the back of the Tylosaurus in the movie also resemble the one in the painting.
- Tylosaurus was originally going to appear in Dinosaur, but it never made it to the final cut. Although, there is a design of the creature for the film.