Tylosaurus - (pronounced TIE-low-SAWR-us)

Tylosaurus was a mosasaur, a large, predatory marine lizard closely related to modern monitor lizards and to snakes. Along with plesiosaurs, sharks, fish and other genera of mosasurs, it was a dominant predator of the Western Interior Seaway during the Upper Cretaceous period.

 

Tylosaurus proriger was among the largest of all the mosasaurs (along with Hainosaurus and Mosasaurus hoffmanni), reaching maximum lengths of 15 metres or more (49 feet).

A distinguishing characteristic of Tylosaurus is its elongated, cylindrical premaxilla (snout) from which it takes its name and which may have been used to ram and stun prey and also in intraspecific combat.

Stomach contents associated with specimens of Tylosaurus proriger indicate that this ferocious mosasaur had a varied diet, including fish, sharks, smaller mosasaurs, plesiosaurs and flightless diving birds such as Hesperornis.

In some paleoenviroments, Tylosaurus seems to have preferred shallow, nearshore waters (as with the Eutaw Formation and Mooreville Chalk of Alabama), while favouring deeper water further out from shore in other environments (as with the Niobrara Chalk of the western U.S.).

Scientific Classification:

Kingdom: Animalia

Phylum: Chordata

Class: Sauropsida

Order: Squamata

Suborder: Lacertilia

Family: Mosasauridae

Genus: Tylosaurus

Species:
T. proriger
T. nepaeolicus
T. haumuriensis
T. kansasensis
T. capensis