The Gulf of Alaska once was a major harpooning zone for the giant filter-feeding mammals, whose worldwide population is about 12,000.

That gets you just about down to the size of the titanoheres - the giant mammals that lived until the end of the Pliocene.

The giant humans had existed along with the giant mammals.

The land became drier, food became less abundant, and as a result of the giant mammals became extinct.

Character designer Peter de Sève welcomed the new plot addition, since he could not think of any other giant mammal to put into the story.

Whale hunters have been harpooning the giant mammals since the 15th century here, and whale meat remains a local delicacy.

No wonder a party of hunters so armed dared to go against the mammoth and the other giant mammals of the period.

The giant mammals did not survive, however.

Like other fishermen, he usually beat his boat with a stick to try to frighten the giant mammals away, but for once he hesitated.

I like to bite the heads off seals,' said the giant marine mammal.