Gigantic 20-Foot Shark Unearthed in Texas

The fossilized remains of a gigantic, 20-foot shark - the size of a two-story building and over 100 million years old - have been unearthed in Texas.

Leptostyrax macrorhiza is believed to be among the biggest predators of its time, and pushes back scientists' notions of when such colossal predatory sharks evolved.

It may have been hard to miss this massive fish when it roamed the ancient ocean, but until now its existence had eluded scientists. So how exactly did researchers stumble upon the fossils of this sea monster? Like most good finds, it was discovered by accident.

In 2009, study co-author Joseph Frederickson went to the Duck Creek Formation on the outskirts of Fort Worth as part of an amateur paleontology club trip. The area is well known for a slew of invertebrate marine fossils, such as squid-like ammonites, and is believed to have been a part of the Western Interior Seaway nearly 100 million years ago.

While taking a tour of the Duck Creek Formation, Frederickson's then-girlfriend (now wife) Janessa Doucette-Frederickson slipped over a boulder and noticed a massive vertebra protruding from the ground. The team eventually managed to dig out three large vertebrae - each of which measured a whopping 4.5 inches (11.4 centimeters) in diameter.

"You can hold one in your hand," Frederickson, a doctoral candidate in ecology and evolutionary biology at the University of Oklahoma, told Live Science, but that's all that your hand can fit.

Further examination revealed that the vertebrae belonged to one of the biggest marine predators of the Early Cretaceous seas, measuring between approximately 20 and 22 feet long. It's reportedly part of the lamniform family, which includes the notorious great white, sand tiger sharks and goblin sharks. However, the fossilized remains indicate that this gigantic Texas shark towers over even these well-known, modern-day predators.

"Jaws from the movie was 24 feet long so this thing would have been about the same size," Frederickson told Oklahoma's News 6.

A similar shark vertebra was unearthed in 1997 in the Kiowa Shale in Kansas, which also dates to about 100 million years ago. That vertebra came from a shark that was even more enormous, up to 32 feet (9.8 meters) long.

By comparing the new vertebra with the one from Kansas, the team concluded the Texas shark was likely the same species as the Kansas specimen.

The new study, which was published in the journal PLOS ONE, suggests this creature was much bigger than previously thought, Frederickson said.

Previously, researchers thought the only truly massive predators of the Early Cretaceous period were the fearsome pliosaurs - relatives of modern-day lizards that could grow to nearly 40 feet (12 m) in length. But now, it seems that there was room for more than one top predator on the block.

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