LAUREL, Md. (CNN) – A dinosaur bone found about three months ago in Maryland is from a giant creature that lived 50 million years before the T-Rex.

It’s a 3-foot-long leg bone from an acrocanthosaurus, a 38-foot-long carnivore, according to the Prince George’s County paleontologist.

Because fossils of other dinosaur species have been found at the site, it’s now classified as a “bone bed.”

It’s an exciting discovery for paleontologists because bone beds can provide a wealth of information about the animals and their environment.

The bones were found at Dinosaur Park, where miners first discovered fossils in the 1800s.