Additional fossils found nearby since elevate the Dinosaur Park’s classification to a “bonebed,” according to a release from Prince George’s County Parks & Recreation, responsible for the discovery with its paleontologist, volunteers and the Maryland-National Capital Park & Planning Commission.
Paleontologists use the term “bonebed” when bones of one or more species are concentrated within a geologic layer. This is the first dinosaur bone bed discovered in Maryland since 1887, according to the release.
“Finding a bonebed like this is a dream for many paleontologists as they can offer a wealth of information on the ancient environments that preserved the fossils and provide more details on the extinct animals that previously may have only been known from a handful of specimens,” said JP Hodnett, M-NCPPC, Department of Parks and Recreation, Prince George’s County Dinosaur Park Paleontologists and Program Coordinator.
“Most paleontologists have to travel across the country or go overseas to find something like this, so having this rare find so close to home is fantastic!”
Fossils found at the park are 115 million years old (Early Cretaceous period), occurring approximately 50 million years before the Tyrannosaurus Rex, according to the release. The area represents what remains of an Early Cretaceous period river and wetlands, similar in environment to the Patuxent River Park in Upper Marlboro, Maryland today.
The fossils found will be excavated out of the field and will be cleaned, examined, and cataloged into the Department’s museum system.
Hodnett made the initial discovery and classified the three-foot-long shin bone as a therapod, a branch of the dinosaur family that contains carnivorous dinosaurs such as Tyrannosaurus rex.
His initial hypothesis of this fossil is an Acrocanthosaurus, the largest theropod in the Early Cretaceous period, estimated to measure about 38 feet long. Acrocanthosaurus teeth have been previously collected from Dinosaur Park, the release stated.
“Dinosaur fossils are exceptionally rare in the eastern US, and among these only Maryland has produced dinosaurs from the Early Cretaceous Period,” said Matthew Carrano, a Smithsonian paleontologist. “Typically, only one or two bones are found at a time, so this new discovery of a bonebed of fossils is extremely important.
“It is certainly the most significant collection of dinosaur bones discovered along the eastern seaboard in the last hundred years,” Carrano said.
University of Maryland Paleontologist Thomas Holtz was the first to verify the therapod discovery at the park, stating, “The dinosaur site at Laurel is by far the most important dinosaur dig site in America east of the Mississippi. It is historically significant, as it was one of the first dinosaur fossil sites found in the U.S. More importantly, it gives us insights into the diversity of animals and plants at a critical period in Earth’s history.”
The first fossil found in the bonebed was a four-foot-long limb bone encased in ironstone of a large dinosaur, the identification is unknown at this time.
Priconodon, a large, armored dinosaur, teeth, osteoderms, and vertebra
Sauropod (Long Necked plant-eating dinosaur, 60-70 feet long), possibly Astrodon, one tail vertebra.
Ornithomimoid, ostrich-like dinosaur, ankle bone, claw, and a vertebra
Large theropod, possibly Acrocanthosaurus, 3-foot-long shin bone from a 35+ foot long meat-eating dinosaur.
Deinonychus, a bird-like predatory dinosaur and larger Velociraptor-relative, tooth
Small tyrannosaur, early T. rex relative and first evidence of this group in Maryland, potential oldest in Eastern North America, tooth.
Small theropod (coelurosaur), chicken-sized meat-eating dinosaur and distant relative to T. rex, thigh bone.
Crocodile, tooth.
Turtle, multiple shell segments and limb bones, possibly more than one individual.
Stingray, oldest North American fossil representative, 2nd oldest globally, tail barb.
Coprolites- fossilized animal poops.
Large freshwater clam.
Large, carbonized conifer wood log segments.
Carbonized seed cone clusters.
“This discovery marks an extraordinary milestone in the field of paleontology and opens a window into the ancient world and species that once roamed this land millions of years ago,” said Peter A. Shapiro Chairman of The Maryland-National Capital Park and Planning Commission. “We are proud of our dedicated team of experts at the Department of Parks and Recreation, Prince George’s County and their ongoing efforts in preserving and studying our natural heritage.”
The Dinosaur Park, around 90 miles north of Culpeper, is a property of the Maryland-National Capital Park and Planning Commission. The public is provided a variety of educational experiences assist Dinosaur Park staff and be paleontologists for a day.