Hesperornis

Hesperornis was a prehistoric flightless bird from the late Cretaceous period.

Facts
It couldn't fly like other birds do, instead it swam as the modern penguins do. A species of Cretaceous birds that are over six feet long and look similar to penguins. They were so vociferous, it was deafening being in the middle of a colony. They’re flightless, like penguins, but they were far from as cute. Inside their dagger-like bills, they’ve actually got teeth. But just to hold their own, Hesperornis had to be tough. They were around a time where there were truly awe-inspiring predators. Hesperornis spent most of their lives in water. They’re amazingly adapted for diving, with specially heavy bones to help them stay submerged.

But few Hesperornis lived to a ripe old age, because where they’re from, there were so many ways to get eaten: they were common prey for many other sea creatures as featured by the third episode of Sea Monsters. In its turn, Hesperornis feed on fish and squid that it caught with its toothy beak.

The Most Deadliest Sea
A flock of Hesperornis were seen on a beach. A few went into the water and started feeding. Some were killed by a few Xiphactinus and a Haliosaurus.