Scientists have unearthed the fossil remains of an ancient “supershark” in Texas that they believe would have dwarfed the modern great white shark.

Dubbed the ‘Texas supershark’, the beast would have been more than eight metres long from head to tail and lived an estimated 300 million years ago, predating dinosaurs by roughly 70 million years.

A team of paleontologists, led by Dr John Maisey from the American Museum of Natural History, found two fossilised skulls in Jacksboro, Texas, an area of North America once covered by a shallow sea.

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“You don’t see sharks this size again until the Cretaceous [period],” Dr Maisey told Science News.

The team modeled the length of the supershark based on dimensions of other complete specimens of ancient sharks and found it would have been 25 per cent longer than the modern great white.

So big, fish evolved around it

The supershark is the same approximate size as Spielberg’s 8-metre Jaws.

An Australian expert told The New Daily the huge shark would have been one of the “top predators” of its time period.

“Early on, they were probably one of the top predators, so this would also have driven the evolution of their prey,” Dr Eric Roberts, a geologist and paleontologist at James Cook University, said.

“Having them start out so large in their evolutionary history means that they have a major influence on the evolution of fish.

“The great white shark today is big, but it’s nowhere near as big as some of the fossil sharks.”

Discoveries of prehistoric sharks provide a rare insight into the earth’s history as they were seen as “bellwethers” of climate change and extinction.

“The shark’s origins go back to 390 or 400 million years ago, so this [Texas supershark] is placing the evolution of large body size in sharks pretty close to origin of sharks,” Dr Richards said.

The discovery of intact fossilised skulls was significant because most sharks have cartilage rather than bony skeletons.

“Any time we find a skull or a partial skull … [it gives us] a tremendous amount of information that you won’t get with most shark discoveries,” Dr Roberts said.

“When we do see these rare, old sharks that do have skulls preserved, especially with the Texas supershark, it tells us that their predatory nature is probably what’s driving their evolution.”

Megalodon, the largest known shark, probably evolved after the ‘supershark’. It is believed to have grown up to 18 metres, making it more than half the size of a blue whale.

Prehistoric sharks were just plain weird

The helicoprion had a mouth like a buzz saw. Photo: Wikia

Although the Texas supershark can claim to be the largest ever shark, it has nothing on the Helicoprion when it comes to sheer anatomical weirdness.

The true anatomy of Helicoprion, which lived around 290 to 250 million years ago, evaded scientists for over a century since its discovery in 1899 due to the mysterious nature of its “spiral-tooth whorl”, which can best be described as a circular saw blade.

It was only two years ago that this toothy problem was solved when a team led by Leif Tapanila from Idaho State University used a CT scan to generate a three-dimensional model of the animal.

“Our reconstruction posits that the tooth whorl is a singular, symphyseal [fused] structure of the lower jaw that occupied the full length of the mandibular arch,” Mr Tapanila wrote in the study published in Biology Letters in 2013.

James Cook University’s Dr Roberts said there were dozens of other species of shark that “experimented” with weird configurations of jaws and teeth.

“Some of the relatives of modern sharks did some of the most bizarre and weird and wonderful things.”

Top image credit: Daryl Toh / tumblr

Supershark would’ve been two metres longer than this great white

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Warning: the video below contains some coarse language.