These large, carnivorous reptiles would’ve devoured us alive. Luckily, these now extinct animals no longer roam the seas, so we don’t have to worry while swimming in the ocean. They became extinct at the beginning of the Cretaceous Period, and were pretty deadly to other animals around them. It wasn’t until 150 million years ago when they went extinct, because a more vicious reptile emerged, the mosasaur, which ended up destroying the Liopleurodon (History of Yesterday).
These extinct animals are giant orthoconic cephalopods, which inhabited the earth during the Ordovician period. They were first spotted 470 million years ago. They’re most similar to modern day squids, cuttlefish, and octopus. At the opening of a hard cone-like shell was their head, which was soft muscular tissue. They used their long, slithering tentacles to manipulate and capture prey. If we were alive millions of years ago, these are the types of tentacles you wouldn’t want wrapped around your foot in the middle of the ocean. Just look at how massive that animal is! Their toothed tongue would aid in devouring the flesh of their prey. We wouldn’t even have a chance if one of these captured us (Wikipedia)