Class – Reptilia
Order – Squamata
Family – Mosasauridae
Genus – Tylosaurus (“Knob Lizard”)
One of the biggest marine meat-eaters of its time period, Tylosaurus was an apex predator that fed on pretty much anything it encountered. Stomach contents in Tylosaurus fossils reveal it fed on other mosasaurs, plesiosaurs, birds, fish, sharks, turtles, squid, Ammonites, and more.
Tylosaurus bite marks were even found on a species of duck-billed dinosaur, though it’s likely the dinosaur had died and drifted out to sea, where it was scavenged by the Tylosaurus.
Bite marks have also been found on the skulls of Tylosaurs, implying that they may have been territorial and aggressive toward each other.
Tylosaurus was a large mosasaur, a seagoing predatory reptile that lived during the Late Cretaceous, from 90 million to about 66 million years ago.
It was one of the largest mosasaurs, growing over 50 feet long. Other than its size, much of its body was similar to other mosasaurs, with a large and pointed head with strong jaws full of sharp teeth, and four paddle-shaped limbs to help proper it through the water. Its tail was long and compressed, and recent discoveries show that it likely had a pointed upper lobe, giving the tail an almost shark-like appearance.
What set Tylosaurus apart from other mosasaurs was the protuberance in the front of its nose. The teeth in its jaws stopped well before the tip of its snout, which had a cone-shaped projection which it may have used in combat, to ram other Tylosaurs or other animals.
Skin impressions show that its body was covered in scales.
Length: 15.8 meters (52 feet)
The first Tylosaurus remains were found in Kansas. They were described by paleontologist Edward Drinker Cope in 1869. Better skeletal material and further studies led to a more complete picture of Tylosaurus in the late 1800s and early 1900s. As more and more material was discovered, scientists continued to learn more about Tylosaurus, through the 1900s and as recently as the 2020s.
It is believed that Tylosaurus and other mosasaurs were closely related to today’s snakes and monitor lizards (like the Komodo dragon).