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10 Extinct Sea Creatures As Terrifying As The Dinosaurs

Batul Nafisa Baxamusa
Our Earth is much older than the reign of dinosaurs and there were many such nightmarish creatures who ruled the world. They were huge ocean-dwellers and could easily tower over the great white sharks. These scariest extinct sea creatures could gobble up a human like a tea-time snack. Discover the unknown world of extinct deep sea creatures in this story.

1. Megalodon

The Megalodon is one of the largest extinct sea creatures.

Megalodon means 'Big Tooth'. They lived around 23 to 3.6 million years ago! This means they were around even before the dinosaurs. Megalodon swam the warm oceans as well as survived the ice age.

They went extinct during the early Pleistocene when breeding grounds and food became scarce.

2. Liopleurodon

If you find the crocodile scary, then meet Liopleurodon. It belonged to the Plesiosaurs group of marine reptiles.

It lived during the Cavollian stage of mid-Jurassic Period. This carnivorous beast could grow upto 30 feet or more. It had huge jaws with a set of razor-sharp teeth. You would not want to dip even a finger in waters where the Liopleurodon swam.

3. Sarcosuchus

Speaking of crocodiles, the Sarcosuchus looked like a modern-day croc.

Sarcosuchus, meaning 'Flesh Crocodile', lived 112 million years agoThese reptiles from the early Cretaceous period were twice the size of the largest saltwater crocs today, and could weigh 8 metric tons. They were so huge that even dinosaurs could become an easy prey for them.

4. Tylosaurus

A large mosasaur i.e. an aquatic lizard is another scary one on our list of 'Extinct Sea Creatures'. 

Tylosaurus had a powerful tail and paddle-like limbs. Its muscular jaw could swallow the prey whole. The two rows of sharp teeth on the upper and the lower jaw made sure nothing could escape its bite alive.

5. Mosasaurus

It is a relief that Mosasaurus is no longer around. It belonged to genus mosasaurs and existed during the Maastrichtian age of the late Cretaceous period

It could grow about 17 meters in length and could easily swallow a human whole. The limbs of this creature were modified into flippers and it appeared like an overgrown crocodile.

6. Dunkleosteus

The Dunkleosteus was a monster fish which lived during the Devonian period.

It was heavier than a bus and longer than a whale. In place of teeth, it had bony plates in its massive jaw. It could easily chomp a shark into two.

Dunkleosteus lost the race of survival due to the drop in oxygen levels in the ocean.

7. Basilosaurus

Basilosaurus, though looked like a monstrous lizard, was a whale. It was one of the largest (but not the scariest!) sea creatures which existed about 40 to 35 million years ago.

It was an ancestor of the whales today, predatory in nature and measured about 50 to 80 feet long.

8. Mauisaurus

Named after the Maori god Maui, this was an enormous sea creature which measured about 26 feet in overall length.

It lived around the Cretaceous era and was concentrated in regions around New Zealand.

9. Kronosaurus

Kronosaurus is another one from the extinct pliosaur group. While it measured about 34 feet long; its massive mouth measured about 5.9 feet!

This huge sea creature could devour an entire human and still had the hunger to gobble up another half a man.

10. Helicoprion

Helicoprion belonged to the extinct eugeneodontid holocephalid fish.

This strange creature had a lower jaw with a tooth whorl. It looked like a cross between a shark and a circular saw blade. There is a bit of a debate about its diet. It is assumed that it was a carnivore, but maybe they survived on a softer diet such as jellyfish.
Some scariest sea creatures lost the game of survival and went extinct. Nature knew these creatures had no place in today's world and eliminated them from the race.

But, the Giant Stingray is one such specie of sea creatures that is alive today. It still lurks in the brackish and freshwater of rivers like Mekong in Southeast Asia till northern Australia...!