Giant orthocone

Edwardchristhoper.blogspot.com - A Giant Orthocone was a nautilus that resembled a squid in an ice-cream cone. It was also related to modern-day squids. They existed 470-440 million years ago in the Ordivician period. Though they had bad eyesight, it did not matter as they lived deep, where most creatures could not see them coming. They had crushing tentacles at up to 6 feet long and ate anything it could, including sea scorpions. It was the top predator of the Ordivician seas.

Source : http://seamonsters.wikia.com