Halisaurus was a species of Mosasaur from the Late Cretaceous.


Halisaurus was a scavenger that feeds upon the remains of others' kills, and small fish and ammonites.

Halisaurus was a mosasaur. But it was much smaller than PlatecarpusHainosaurus and Tylosaurus. It loitered in submarine caves and cracks. It may have waited around ledges above the water where Hesperornis gathered.

250px-Little Mosasaur

When Hesperornis leave their rocky ledges to dive for fish, Halisaurus are down formations. And below, waiting for an opportunity to ambush them. Mosasaur teeth are good at piercing the skin of their prey but bad at slicing flesh. So once Halisaurus has caught its prey, it swallows it. Its jaw has flexible joints within it and can open incredibly wide.

260px-SM1x3 Haliosaurus

In Sea MonstersEdit

To Hell... and Back?Edit

Halisaurus made a brief appearance in the Cretaceous segment of this episode waiting to ambush a diving Hesperornis.

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