Until Now
Biology

Giant nautiloids rule the seas

Straight-shelled cephalopods up to nine metres long become the largest predators yet to exist.

When
Known to
± 10 million years
Era
Ordovician, Paleozoic

Endocerid nautiloids such as Cameroceras carry cone-shaped shells that in the largest species may have reached several metres, making them by a wide margin the biggest animals of their time. Jet-propelled and equipped with tentacles, they hunted trilobites, eurypterids and each other. They dominate for tens of millions of years, then are hit so hard by the end-Ordovician extinction that they never recover.

Just before

Just after