A close-up of the dentition of an ancient marine, carnivorous lizard, the mighty Mosasaur, from Late Cretaceous exposures on Vancouver Island. Mosasaurs were air breathers and powerful swimmers. 

They gave birth to live young, similar to sea turtles, seeking out the safety of a sandy shore to lay their eggs. This well-prepped specimen is housed in the collections of the Courtenay Museum, Vancouver Island, British Columbia. 

The creature who belonged to this jaw bone undoubtedly swan alongside Kourisodon puntledgensis, another enormously powerful marine predator and new species of Mosasaur unearthed on Vancouver Island. Their feet modified into flippers, they were expert swimmers and hunters, with a strong tail for propulsion. These two would have commanded our ancient seaways between 70 and 66 million years ago.