- Bruce (Tylosaurus pembinensis)
- 13.05 metre(s)
- Canada (Morden)
Mosasaurs were prehistoric carnivorous marine lizards related to today's varanids or monitor lizards. The largest mosasaur currently on public display is Bruce, a 65-70%-complete specimen of Tylosaurus pembinensis dating from the late Cretaceous Period, approximately 80 million years ago, and measuring 13.05 m (42.815 ft) from nose tip to tail tip. Bruce was discovered in 1974 north of Thornhill, Manitoba, Canada, and resides at the nearby Canadian Fossil Discovery Centre in Morden.
Family: Mosasauridae Subfamily: Tylosaurinae Genus: Tylosaurus Species: Pembinensis
Bruce swam in a deep sea environment with numerous other marine reptiles. This ocean is termed the Western Interior Seaway and split North America in two. The Seaway spanned from the frigid waters of the Arctic Ocean to the warm currents of the Gulf of Mexico. Bruce belonged to a group of Mosasaurs called the Tylosaurs, the largest of the Mosasaurs. Bruce was a fierce predator, top of the food chain in the Seaway eating anything it its path from plesiosaurs to ammonites (shelled organisms). The tail of Bruce is exceptionally long, moving side to side to propel him forward with snake-like undulations, while the large flippers primarily steered. Palaeontologists think the Mosasaurs lineage was branched off from a lizard group known today as the Monitor Lizards. In 1974 Bruce was discovered north of Thornhill, Manitoba within the Pembina Member of the Pierre Shale Formation. It took approximately two field seasons to excavate the skeleton. The Canadian Fossil Discovery Centre has the largest collection of marine reptile fossils in Canada and one of the largest in the world.