10 Prehistoric Sea Creatures We’re Thankful Are Extinct

For those who can never get enough of the wild wonders of dinosaurs and the terrifying beasts that once lived over a million years ago, the joy of reading and seeing the imagery of such creatures will never suffice. Once upon a time, there were some truly massive marine animals roaming under the waters across the planet, and these things had no problem ripping apart anything that got in their way. Here are ten terrifying sea monsters you definitely don’t want to swim with.


The Shastasaurus was a marine predator that looked similar to the modern-day dolphins, though they could reach some truly massive sizes; up to 65 feet in length. They lived 200 million years ago, and mostly fed on smaller fish.


The Dakosaurus was first discovered in the oceans around Germany. These were one of the biggest predators reigning the seas during the Jurassic Period. They had a weird reptilian-type body that was covered in scales and rough skin.