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Credit: Lomax and Massare, 2017, NLMH 106234

10 Craziest Sea Creature Fossils Ever Discovered

Today's sea creatures are awesome, but when we look at fossils from the crazy sea monsters of yore, it's kind of hard to compete.


Today's sea creatures are awesome, but when we look at fossils from the crazy sea monsters of yore, it's kind of hard to compete. Sure, blue whales are huge, but do they have killer teeth that can crunch turtles in half? Well, maybe it's a good thing that we're many millennia removed from these sea monsters. But in honor of National Fossil Day, here's a list of the craziest sea creature fossils to ever be unearthed!

1. The Sea Dragon Fossil

Ichthyosaurus somersetensis (Credit: Lomax and Massare, 2017, NLMH 106234)

The fossil was discovered in the mid-90s and put on a display in a museum, but we guess it wasn't examined very closely, because years later scientists realized it was a completely different, previously undiscovered creature.

It's the biggest of the "sea monster" genus (what a genus!) at about 10 feet long. Interestingly, the fossil has an embryo, too, which upon inspection makes it look like this sea monster may have given birth to live young.

2. The Master Spirit From the Volga Fossil

Luskhan itilensis (via Shutterstock)

A fossil of this giant reptile was discovered in Russia in 2002 on the bank of the Volga River. And we're talking giant: Its head alone was about 5 feet long with a dolphin-like beak. A type of pliosaur, its translated name means "Master spirit from the Volga." An intimidating name to match a killer creature!

3. The Fossil With 50 Legs

Credit: Royal Ontario Museum

This 507 million-year-old sea creature only had, oh, 50 legs. It also had cool multipurpose pincers that could grasp, crush and cut its prey — kind of like a prehistoric, living, Swiss army knife!

4. The Heavy-Metal Fossil

Credit: Wikimedia Commons

You have to be a pretty hardcore sea crocodile to be named after the founder of legendary metal band Motorhead. Experts re-examined an old fossil at London's Natural History museum (seriously, do we even need to look for fossils? Just check the back room at the museum!) and realized the ancient croc was a whole different species.

Credit: Mark Witton, Trustees of the Natural History Museum, London

A curator who was a fan of heavy rock decided to name him after Motorhead's founder, Lemmy, who had recently passed away. The Lemmysuchus was one of the fiercest marine creatures of its day — it could snap a turtle in half in a single bite. Rock and roll!

5. The 'This Isn't an Elk!' Fossil

Photo Credit: Flickr, Gerry Thomasen

If we had a dollar for every time we went out looking for elk and found a previously undiscovered prehistoric sea creature instead … Well, we would have $0, but one man in Montana did make this pretty awesome discovery in a stream near his home.

This previously unknown type of elasmosaur, characterized by its long neck and generous flippers, swam in the wilds of Montana back when there was an inland sea flowing east of the Rocky Mountains.

6. The Colorful Fossil

A mosasaur. (Credit: Shutterstock)

Fossils tell us a lot about an ancient creature, but not generally its color. Scientists were able to develop high-tech methods of tracking chemical traces of soft tissue that still had pigment in them.

They discovered that three ancient sea creatures — the leatherback turtle, mosasaur and ichthyosaur — were all darkly colored. We were picturing something a bit more festive, but it's still a cool finding.

7. The 'We're Going to Need a Bigger Boat' Fossil

If you think great white sharks are big and scary, you're lucky you never met the Megalodon, a prehistoric shark that was the biggest in history. The largest Megalodon jaw ever assembled — by a famed fossil hunter, no less — measures 11 feet across and almost 9 feet tall.

8. At Least This Fossil Wasn't Hungry ...

We now know what one poor ichthyosaur, which look like today's dolphins, had to eat before he died. It was a tasty squid. We hope he enjoyed it. And either way, the resulting fossil looks pretty cool — you can see hook-like structures that are the prehistoric squid's tentacles.

9. The Mystery of the Coiled Fossil

Helicoprion jaw fossil (left). (Photo Credit: Wikimedia Commons, James St. John)

Helicoprion shark illustration (right): Wikimedia Commons, Dmitry Bogdanovf

This twisty fossil puzzled scientists for years, leading to the creation of some interesting speculative art featuring sharks with coiled jaws. In the end, scientists concluded that this ancient shark really just had the mouth of a circular saw. As if that's not also really creepy.

10. The Epic Battle Fossil

Credit: Royal Tyrrell Museum of Paleontology

Imagine if your last text-message fight with a friend was preserved in a fossil for all time. That's basically what happened to these mosasaurs.

This ancient undersea creature apparently got in a fight with another of its kind and survived. Its attacker left a little souvenir behind, though: one of its teeth lodged in its eye. Truly a battle for the ages!

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