Largest Dinosaur Foot Yet, One Meter Wide, Found In Fossils From Wyoming

A fossil specimen excavated 20 years ago and nicknamed “Bigfoot” has been shown to be the largest dinosaur foot found so far, a paper published Tuesday said. Discovered in Wyoming, the foot is almost one meter (about 3.3 feet) wide and belonged to a species of dinosaurs called brachiosaur, which wasn’t the largest dinosaur to have existed.

Brachiosaur was a kind of sauropod, the name given to a large group of long-necked, long-tailed herbivore dinosaurs with small heads that included the biggest animals to have ever lived on Earth. They lived for about 100 million years, beginning in the early Jurassic and dying out soon after the advent of the Cretaceous period about 145 million years ago.

Excavated by a team from the University of Kansas in 1998 from the fossil-rich Black Hills region of Wyoming, the foot’s fossil was nicknamed “Bigfoot” by the researchers owing to its size.

“It was immediately apparent that the foot, nearly a meter wide, was from an extremely large animal, so the specimen was nicknamed ‘Bigfoot,’” Anthony Maltese, lead author of a paper describing the specimen and part of the expedition team that discovered it, said in a statement Tuesday. He is now with the Rocky Mountain Dinosaur Resource Center in Woodland Park, Colorado.

Along with identifying the specimen as the largest known foot for any animal ever, and the dinosaur species to which it belonged, the study also found that brachiosaurs lived about 150 million years ago across a large part of present-day United States — from eastern Utah to northwestern Wyoming — apparently an unusual occurrence.

Emanuel Tschopp, coauthor of the paper and a postdoctoral fellow in the American Museum of Natural History's Division of Paleontology, said in the statement: “This is surprising. Many other sauropod dinosaurs seem to have inhabited smaller areas during that time.”

Other than the U.S., the team involved in the study included researchers from Germany and Switzerland. They used 3D-scanning and numerous detailed measurements to make comparisons with a number of other dinosaur species to identify their specimen as belonging to a brachiosaur, as well as to conclude that it was the largest dinosaur foot discovered yet.

“There are tracks and other incomplete skeletons from Australia and Argentina that seem to be from even bigger animals, but those gigantic skeletons were found without the feet. This beast was clearly one of the biggest that ever walked in North America,” Tschopp said, referring to the larger titanosaurs and other dinosaur groups found in those countries in the Southern Hemisphere.

Titled “The real Bigfoot: a pes from Wyoming, USA is the largest sauropod pes ever reported and the northern-most occurrence of brachiosaurids in the Upper Jurassic Morrison Formation,” the paper appeared online Tuesday in the open-access journal PeerJ.