Hesperornis lived during the Late Cretaceous period 75-65 million years ago.
Hesperornis was a species of Cretaceous birds that were over six feet, 2 meters, long and looked similar to penguins. They were flightless, like penguins, but they were far from as cute. Inside their dagger-like bills, they actually had teeth. But just to hold their own, Hesperornis had to be tough because they were around a time where there were truly awe-inspiring predators in the seas.
Hesperornis spent most of their lives in water. They were 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 were from, there are so many ways to get eaten.