Supersized Shark Fossils Found in Texas

Mark McKinzie and Robert Williams, fossil hunters from the Dallas Paleontological Society, found some remains of that first type of supershark in Jacksboro, Texas. The fossils that are found are believed to be fragments of the brain cases of a type of shark which is smaller than the mighty megalodon. It was also found out that they're considerably older than previously found giant shark specimens, by about 170 million years.

Scientists found the newfound fossils "Texas Supershark". They are 26 feet long or more than half the length of a school bus.

The Dallas Paleontology Society donated the fossils to the American Museum of Natural History in New York for further study. Museum researchers presented the findings on these specimens on October 16 at the annual meeting of the Society of Vertebrate Paleontology in Dallas.

The Supersharks lived before the age of dinosaurs which are 230 million years ago. Until now, the oldest giant shark was found in rocks dating to 130 million years ago.

John Maisey, the curator of vertebrate paleontology at the American Museum of Natural History who studies rare shark and shark-like fish fossils, describes this type of prehistoric shark as a "massive top predator" that swam in fairly warm oceanic conditions and might have been able to maintain its blood temperature just like modern sharks such as the great white and the mako.

When supershark was alive, during the Carboniferous period, a shallow sea called the Western Interior Seaway covered Texas and much of the American West. The other fossil remains are still being unearthed. Another collector found a number of large and pointy, fossilized shark teeth, but it's unclear whether these belonged to the Texas Supershark or to another ancient species.

"What we've got are bits of cranium or a brain case that don't have any real diagnostic features, but we can see what group they belong to," Maisey said. "There are other, more complete fossils of these kinds of sharks that do have similar teeth."

"This shark from Texas is somewhere around about 300 million years old, and that's pretty far back from other Cretaceous ones that tend to be about 75-80 million years old, so there's a gap in between from the age of the dinosaurs," Maisey said. "You also never see sharks that are more than 3 meters [9.8 feet] long. The biggest one I ever saw was more than 3 meters and it didn't have very big teeth. That doesn't mean that they didn't exist, but we just haven't seen them."

To calculate the body size of the supershark without a complete specimen, they looked to the dimensions of other complete specimens of ancient sharks known as ctenacanthiforms, which are a group of ancient sharks that lived during the Carboniferous period. The skulls of these ctenacanthiforms accounted for roughly 10 percent of the sharks' entire body length, the researchers found.

"All of these [estimates] are very preliminary since we only have these fragments," he said. "We know what they are and we know they were big and we can only estimate their body size."

Further research is needed to determine whether the Texas supershark specimens represent a known species, such as Glikmanius occidentalis, or a species that has yet to be discovered, Maisey said. But the newly found shark's close relative, the ancient shark from Scotland.