Paleontologists have unearthed a dinosaur “bone bed” including the largest leg bone ever found in the eastern U.S. at the Dinosaur Park in Prince George’s County, county officials announced Wednesday. 

A “bone bed” refers to a geological layer containing fossilized bones from numerous prehistoric species. In this case, the bed’s layer and the bones date back roughly 115 million years to the Cretaceous period, the last of the three epochs in which dinosaurs lived.

A three-foot-long shin bone has been found, believed to come from Acrocanthosaurus, a theropod. Theropods were a carnivorous group of reptiles including the more famous velociraptors and Tyrannosaurus rex.

The leg bone found is the largest ever found in the eastern U.S., according to the Prince George’s County Department of Parks and Recreation.

“Dinosaur fossils are exceptionally rare in the eastern U.S., and among these only Maryland has produced dinosaurs from the Early Cretaceous Period. Typically, only one or two bones are found at a time, so this new discovery of a bone bed of fossils is extremely important,” Smithsonian Institution paleontologist Matthew Carrano told WJLA-TV.

The Dinosaur Park area is also one of America’s oldest such dig sites. Until the recent bone bed discovery, a similar formation had not been found there since 1887.

• Brad Matthews can be reached at bmatthews@washingtontimes.com.