Roughly 300 million years ago during the time called the Carboniferous period, Texas was flooded by a shallow sea, and these waters held a dark secret. In a time even before the age of dinosaurs, there was a predator of huge proportions; giant sized sharks the length of a limousine were lurking in the warm water.
The new giant shark fossils were unearthed in Jacksboro’s Lost Creek Reservoir, and they are huge. They aren’t world record breakers measuring nearly 26 feet (8 meters), but they are about 25% larger than the modern-day great white.
“You’ve got a bunch of very enthusiastic fossil collectors living in the Dallas/Fort Worth area,” Maisey told the Jacksboro Newspapers.
“I’m a researcher of extinct sharks and shark evolution. They contacted me and said: ‘We’ve got some shark pieces. We don’t know what they are,’ and graciously donated them. It’s really exciting.”
Mark McKinzie and Robert Williams of the Dallas Paleontological Society made the discovery 10 years ago, but have now donated the fossils to the American Museum of Natural History in New York. Together with the curator in the Division of Paleontology, John Maisey, they estimated the shark’s size by comparing them with smaller, more complete fossils of closely related sharks.
“What we did was scale it up to fit the size of these fragments,” Maisey said. “The brain case of the more complete skeletons were about 10 percent of the total body length. We came up with an overall brain case length of 85 centimeters (33.5 inches). Although they are fragments we identify them to the family and scale them, we can reasonably estimate.
“It’s all pretty speculative, but we know they were really, really big and that’s as empirical as we can get with this,” he added.
Everything is bigger in Texas, even 300 million years ago,
Maisey said in a statement.
The fossils are believed to be fragments of the brain cases, and are older than any previously found giant shark specimens by about 170 million years. The largest shark, known as the “Megalodon,” is much younger, roaming the waters around 15 million years ago. The new fossils from Texas now indicate that giant sharks go much further back into the fossil record.
Maisey said at the Society for Vertebrate Paleontology annual meeting that there have been fossils of ancient sharks before, but not as old as these, adding;
You don’t see sharks this size again until the Cretaceous.
Because sharks have cartilage instead of bones, scientist rely on their teeth for fossil records. With no teeth to be found, further research is needed to determine if the Texas giant shark specimens are of a known species, such as Glikmanius occidentalis, or if it is an entirely new species.
Maisey said that they “can’t identify the species or genus without any associated things like teeth.”
McKinzie, a geologist who lives in Grapevine, has been collecting fossils for around 50 years.
“I knew it belonged to a big shark at the time, but I didn’t know anyone in the United States who worked on these fossil sharks so I didn’t know where to send it to,” McKinzie told Jacksboro Newspapers. “When Bob [Williams] found his, I saw a scientific paper and I learned John Maisey was the person.”
Museum researchers presented their findings on these specimens at the annual meeting of the Society of Vertebrate Paleontology in Dallas.