Tylosaurus Facts for Kids

Quick facts for kids Tylosaurus Temporal range: Turonian–Maastrichtian, ~92.1–66Ma PreЄ Є O S D C P T J K Pg N

Skeleton cast of Tylosaurus rex
Scientific classification
Unrecognized taxon (fix):	Tylosaurus
Type species
†Macrosaurus proriger Cope, 1869
Species
†T. proriger †T. nepaeolicus †T. ivoensis †T. iembeensis †T. kansasensis †T. rex †T. bernardi †T. gaudryi †T. pembinensis †T. saskatchewanensis

Tylosaurus was a giant marine reptile that lived during the Late Cretaceous period. It belonged to an extinct family of ocean lizards called mosasaurs. These creatures swam in ancient seas between 92 and 66 million years ago. Its fossils have been found across North America, Europe, and Africa. As an apex predator, it hunted at the very top of the ancient ocean food chain.

What Did Tylosaurus Look Like?
Hunting and Diet
Discovery and History
Amazing Biology and Growth
Images for kids
Related pages
See also

What Did Tylosaurus Look Like?

Size comparison of Tylosaurus with a human

Tylosaurus had a streamlined body built for fast swimming. Instead of legs, it had four strong paddles and a long tail with a fin. While early drawings showed mosasaurs swimming like giant sea snakes, scientists now know they swam more like sharks. They moved mainly using the back of their body and their powerful tail.

The largest species was named T. rex in 2026. A famous specimen nicknamed "Bunker" reached about 13.2 metres (43 ft) long. Other species, like T. proriger and T. bernardi, were also huge ocean hunters.

Its name means "knob lizard" because of a hard, toothless snout called a rostrum. Inside the snout were many branches of the ophthalmic nerve. Scientists believe this snout was packed with sensitive nerves to detect vibrations and sense prey in murky water.

Hunting and Diet

Skeletal mount of Tylosaurus chasing prey

Tylosaurus was a fierce carnivore that ate almost anything it could catch. Its jaws held sharp pointed teeth, as well as extra teeth on the roof of its mouth. These extra teeth on the pterygoid bone helped push struggling prey down its throat.

Fossil stomach contents show that Tylosaurus ate:

Large bony fish like Bananogmius and Cimolichthys
Plesiosaurs like Dolichorhynchops
Diving seabirds like Hesperornis
Hard-shelled sea turtles
Other mosasaurs, including Clidastes and Platecarpus

Fossil bite marks on ancient squid and coiled shells show that it also hunted large sea creatures like ammonites.

Discovery and History

Fossil skull drawing of the first T. proriger specimen

The first fossils were found in the Great Plains of the United States. Many stories from Native American folklore about water monsters fighting thunderbirds were likely inspired by these huge bones.

During the late 1800s, two famous rival paleontologists named Edward Drinker Cope and Othniel Charles Marsh argued over its name during the Bone Wars. Cope first named it Macrosaurus proriger in 1869. Marsh gave it the official name Tylosaurus in 1872.

Amazing Biology and Growth

Life restoration of T. nepaeolicus

Scientists have discovered amazing details about how Tylosaurus lived. Microscopic studies of its skin scales showed signs of eumelanin. This meant it was dark in color, which provided camouflage and helped it absorb warmth from the sun.

Tests on bone chemistry reveal that Tylosaurus was warm-blooded. Its internal body temperature was about 34.3 °C (93.7 °F), similar to modern seabirds. Being warm-blooded gave this huge hunter the energy to swim into colder waters and chase fast prey. Like modern sea snakes and some other marine reptiles, mosasaurs gave birth to live young in the open sea.