Ancient “Predator X” Identity Was a Long-Held Mystery

Written by Colby Maxwell
Published: October 7, 2022
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The fossil record is like a box of chocolates — you never know what you are going to get! A few years ago, that was surely the case when scientists discovered a massive marine predator that supposedly had a bite force four times stronger than that of a T-rex. Initially named Predator X, this creature wasn’t fully released to the public before the nicknames began to run amok. Today, we are going to learn about Predator X and why it wasn’t fully revealed for so long! Let’s get started.

What Was Predator X?

Ancient "Predator X" Identity Was A Long Held Mystery
Predator X was a unique reptile that has a name that is as shocking as its reputation.


Predator X is simply the name given to Pliosaurus funkei, a massive marine pliosaur found in 2009.

Generally, the public eye has a strange relationship with the field of paleontology. If it isn’t the biggest, largest, scariest creature to have ever been discovered, people rarely care about it. This is clearly evident in the felt need to make each Jurassic Park dinosaur bigger and scarier, a theme explored in the first Jurassic World.

In most situations, researchers will release a study with their findings and the media will publish stories, depending on how sensational the finds were. In the case of Predator X, however, things got a bit reversed. When the fossil remains of a large marine creature were discovered, the news escaped before the researchers had time to, well, research! Without a proper name, the media began referring to this large mystery fossil simply as “Predator X.”

Before the creature had been named, a documentary by the History Channel, multiple news articles, and a ton of media coverage had already declared Predator X to be the scariest predator of all time. Scary sells! It would take researchers nearly six years before scientists officially named Predator X, dubbing it Pliosaurus funkei.

The Real Story of Predator X

Ancient "Predator X" Identity Was A Long Held Mystery
Predator X is one of the largest pliosaurs ever to live.

©Michael Rosskothen/

Although Predator X is a great name to drum up media hype, the real story of Pliosaurus funkei, the name later given to the prehistoric beast, is still pretty interesting.

Pliosaurus funkei belongs to a group of reptiles known as plesiosaurs that lived during the Jurassic and Cretaceous periods. Their bodies were somewhat alligator-like in appearance, although they were much, much larger and had flippers instead of legs. The head of Pliosaurus funkei was extremely large and filled with teeth, allowing it to hunt prey of all types. Pliosaurus funkei was an apex predator and likely fed on fish, sharks, ichthyosaurs, dinosaurs, and even other plesiosaurs.

Although it belonged to a different group, Pliosaurus funkei would have looked somewhat similar to Mosasaurus, the large marine dinosaur that is seen in the Jurassic World movies in the feeding tank. Both creatures lived in the ocean and were at the top of the food chain.

How Big Was Pliosaurus Funkei?

Even though there was a lot of media hype, not all of it was untrue! The fossil remains of Pliosaurus funkei show that the creature discovered in the rock was truly massive and worthy of a lot of the outlandish things said about it.

Using fossil evidence and modeling the potential body of Pliosaurus funkei, scientists estimate that this large creature was likely between 33 and 42 feet long and weighed around 12 tons, making it one of the largest plesiosaurs of all time.

Where Was Pliosaurus Funkei Discovered?

Researchers discovered Pliosaurus funkei on the Norwegian island of Svalbard. This frozen region wasn’t always so cold and was at one point underwater. A team from the University of Oslo found two massive fossils in the same region, both of which turned out to be the same species, Pliosaurus funkei.

When the fossils were discovered, they were extremely degraded due to the seasonal freezing and thawing pattern. Years of of expansion and contraction had caused the fossils to lose integrity. When the researchers went to take the fossils back to their labs, they degraded even further. All of these factors caused a delay on a full paper describing and naming the creature. Additionally, these complications are what allowed the media to take of running with names like Predator X and The Monster!

It was nearly six years after the initial discovery of the fossils that they were officially named, which was three years after headlines with “Predator X” had been circulating.

A Marine Predator

Ancient "Predator X" Identity Was A Long Held Mystery
Pliosaurus funkei may have had a lot of media hype, but it was still one of the biggest predators in the ocean.

©Daniel Eskridge/

Although there was a lot of media attention surrounding predator, not all of it was totally outlandish. Paleontologists (and scientists in general) hate saying things for certain when there isn’t enough data, but media outlets generally don’t have that problem. Still, there are two things that absolutely true when it comes to Predator X:

  • Predator X is currently one of the largest known pliosaurs to have ever been discovered. With an upper length of around 42 feet, this was one big reptile!
  • Predator X was an apex predator. While things like “the biggest predator to ever live” may be a bit overblown, Pliosaurus funkei was most assuredly at the top of the food chain wherever it went. A massive body paired with an alligator-like mouth and a set of monstrous teeth combine to make one of the most fearsome creatures that humans have ever discovered.

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Predator X - a pliosaur - was a massive apex predator
Predator X was a massive apex predator
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About the Author

Colby is a freelance writer from Charlotte, North Carolina. When he isn't distracted by his backyard birdfeeder, you can find him camping, exploring, and telling everyone around him about what he's recently learned. There's a whole world to learn about and Colby is content to spend his life learning as much as he can about it!

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