- Geologists recently discovered the fossil of a Cretaceous-era mosasaur vertebra near Starkville, Mississippi.
- The experts believe the apex predator of the ancient seas could have weighed 20,000 pounds and been 50 feet long.
- The Late Cretaceous-era Mosasaurus hoffmannii was known to eat others of its own species.
Whatever you want to call the Mosasaurus hoffmannii—a giant mosasaur, a massive water dragon, maybe even a sea monster—just know that it was one big dino, and we’ve got the bones to prove it. Geologists in Mississippi recently discovered the vertebra of the Late Cretaceous-era water dinosaur, which could reach up to 50 feet long and weigh 20,000 pounds at its largest. It was truly an apex predator extraordinaire.
The find came in the fossil-rich outcrops of northeast Mississippi, near Starkville in the Prairie Bluff Formation, according to a statement from the Mississippi Department of Environmental Quality, and the discovery sheds new light on the “giant sea lizard” that was a contemporary of the Tyrannosaurus rex, Velociraptor, and Triceratops.
This Cretaceous carnivore was not to be messed with. It had jaws lined with 60 dagger-like pointed teeth curved inward—with additional rows of teeth at the roof of the back of their mouths to help secure large prey, including other mosasaurs—and the subaquatic dinos could regrow the teeth, which they frequently lost while hunting.
“Mosasaurs were sea dragons, both large and small, and were truly the apex predators dominating the various environments of the seas of this time,” according to the state’s geologists. “While the dinosaurs ruled the land, these Mesozoic-era oceans were likely the most dangerous of any time in the entire history of our planet.”
The recent discovery was “from a true giant,” the team said, adding it belonged to a M. hoffmannii, one of the largest and last mosasaurs during the Cretaceous period. Its size, coupled with its agility and speed in the water, made it “one of the most formidable marine predators to ever swim in our planet’s oceans.”
Noting that in a period where much of Mississippi was believed covered by warm, tropical ocean waters, mosasaurs were akin to a giant lizard that was specialized in this environment.
This specimen belongs to the largest-ever M. hoffmannii recorded in the state and would have been larger than most dinosaurs on land. “This is a true, true sea monster,” James Starnes of the Mississippi Department of Environmental Quality’s Office of Geology, told the Hattiesburg American. “This is about as big as mosasaurs get.”
George Phillips, paleontology curator at the Mississippi Museum of Natural Science, told the Hattiesburg American, this find—with a backbone seven inches at its widest point—was likely at least 30 feet long, though the M. hoffmannii is believed to be able to reach 50 feet in length.
“We find them from time to time, but to find one this size is phenomenal,” Starnes said. “The sheer size of this thing blew us away.”
The team located the vertebra in mud while building a three-dimensional map of the site’s geological layers. It may have sat there for about 66 million years, the team believes, ever since the species went extinct at the end of the Cretaceous period.
Tim Newcomb
Journalist
Tim Newcomb is a journalist based in the Pacific Northwest. He covers stadiums, sneakers, gear, infrastructure, and more for a variety of publications, including Popular Mechanics. His favorite interviews have included sit-downs with Roger Federer in Switzerland, Kobe Bryant in Los Angeles, and Tinker Hatfield in Portland.
