There’s a New Mosasaur in Town

The Rivers community gained a new member during March break: a Tylosaurus Proriger.

Our new Red Wing isn’t actually new at all. “Ty” is a fossil of a large, predatory marine lizard – a type of mosasaur that lived between 71-84 million years ago, during the Late Cretaceous Period. The specimen was donated by a current Rivers family, the Vergas, who have participated in similar excavations for the past several years. The fossil now hangs in the Campus Center lobby just above the media wall.

Ty’s name originates from the Greek words tylos, meaning “protuberance” or “knob” and sauros, meaning “lizard.” He is closely related to modern monitor lizards and snakes.

This species of Tylosaurus was among the largest of the mosasaurs, weighing in at about seven tons and often growing to lengths of more than 45 feet. Our specific fossil friend here at Rivers is 24 feet long.

Mosasaurs were proficient swimmers, powered mostly by long, flat, and muscular tails. They breathed air, and lived in warm, shallow inland seas common to their historical time period. In fact, they had adapted so well to their surroundings that they gave birth to live young in this environment, instead of returning to shore to lay eggs.

Ty and his fellow lizard-like relatives had limbs that resembled paddles so they could steer through the water and a cylindrical snout that was likely used to ram and stun prey. Their jaws functioned much like those of snakes, with double hinges, teeth on the roof of the mouth, and a flexible skull that allowed them to swallow their prey whole.

Our Tylosaurus Proriger specimen at Rivers was discovered in the Pierre Shale geological formation in Sheridan County, Nebraska. Stop by and say “hi” to Ty!