Tylosaurus (knob lizard) was a genus of mosasaur from the Cretaceous period.
Tylosaurus was the largest predator of all time. It had all the qualities of a basic mosasaur, such as the long, serpentine body, smooth skin, tail that undulated like a snake, two pairs of powerful flippers, and long, strong jaws filled with sharp teeth. Tylosaurus, like all mosasaurs, was the ancient ancestor of snakes and monitor lizards.
It is not determined by scientists yet as to how big a maximum Tylosaurus actually was. The size could've been anywhere from 30-60 feet long. Its weight is estimated at twenty tons.
Tylosaurus was an ambush predator, probably colored like a great white shark, to blend in with the dark and light of the water. Special pits on its jaw could detect electrical impulses made by living organisms from several miles away, much like a shark. Tylosaurus snuck up from behind on its unsuspecting prey, then, using its powerful tail, propelled itself straight toward its dinner, anticipating to crush it with its powerful jaws. Tylosaurus could've also rammed and stunned its prey with a tough knob at the front of its snout (hence the name "knob lizard").
Tylosaurus, as fossil evidence proves, was an efficient and opportunistic predator. It could eat anything from plesiosaurs to prehistoric sharks to giant sea turtles. A fossil of a hadrosaur found in Alaska bore tooth marks from a species of Tylosaur, suggesting that either the predator ambushed the dinosaur or scavenged the carcass.Bite marks in Tylosaurus bones suggested that it maybe cannibalistic.