About the ParkJoin us in unearthing Prince George’s County’s prehistoric past at Dinosaur Park, home of Astrodon Johnstoni, Maryland’s state dinosaur.
The park is a unique site in Laurel, Maryland, featuring a rare deposit of fossils from the Early Cretaceous period, about 110 million years ago. Here, paleontologists have unearthed fossilized bones of several kinds of dinosaurs and early mammals, and fossils of trees and early flowering plants.
A garden helps to bring the prehistoric past alive with plants and trees similar to those of dinosaur times. Interpretive signs describe Maryland’s dinosaurs and prehistoric environment, and the industrial and African American history of the area. The signs are just outside the fenced-in fossil area which is only accessible during open house hours or by appointment.
History of Dinosaur Park
English scientist Sir Richard Owen coined the term “dinosaur” in 1842 to describe the ancient reptiles that roamed the Earth from 230 to 65 million years ago. Since then, the discovery of dinosaur bones has captured the public’s interest and fueled our imaginations! Though most people associate dinosaur finds with the western United States, significant finds of dinosaur bones and early plant life have been found here at Dinosaur Park making it one of the most important dinosaur sites east of the Mississippi River.
Before the discovery of dinosaur bones, the clays of the Muirkirk Deposit were a source of siderite, or iron ore, and iron furnaces operated in the area as early as the 1700s. The most prominent furnace was the Muirkirk Ironworks located a half mile south of Dinosaur Park and operated from the mid-1800s until the 1920s. African American miners discovered the first dinosaur bones in 1858 in open pit mines near the park.
Among the first scientists to become interested in the Muirkirk Deposit was State Geologist Phillip Thomas Tyson. He brought some of the “strange bones” discovered in the iron mines of the Muirkirk Deposit to a meeting of the Maryland Academy of Sciences in 1859. There they were identified as dinosaur teeth! Academy member and dentist Christopher Johnson named the dinosaur Astrodon for the starburst pattern in a cross section in the teeth. The species name johnstoni was later added to reflect Johnston’s role in identifying Maryland’s first dinosaur, Astrodon johnstoni.
Other scientists interested in the dinosaur finds in Maryland include Professor O.C Marsh of Yale University. In the winter of 1887-88 Professor Marsh sent John Bell Hatcher to collect dinosaur bones from iron mines in Maryland. Hatcher collected at the Muirkirk Deposit and recovered hundreds of bones and teeth, including those of turtles and crocodiles. One specimen was a small sauropod named Pleurocoelus. Some scientists believe Pleurocoelus to be a juvenile Astrodon. Collection of dinosaur bones in Maryland continued in the 1890s by Arthur Bagnold Bibbins whose findings were added to the collections of the Smithsonian Institution. Fossil collecting at the Muirkirk Deposit essentially stopped when the iron industry died out in the early twentieth century and was not revived until the 1980s.
Following the demise of the iron industry in the 1920s, the Muirkirk Deposit was mined for clay to make bricks and pigments for paint. Over the years, many more bones, teeth, and other fossils were recovered in the iron bearing clays of the Muirkirk Deposit, now preserved as Dinosaur Park.
Astrodon johnstoni, Maryland’s State Dinosaur
Astrodon johnstoni was the first dinosaur found in Maryland. Astrodon was a long necked plant-eating dinosaur and may have been a type of sauropod called a brachiosaur or titanosaur. Like all dinosaurs, Astrodon johnstoni walked erect with legs situated under its body (unlike lizards, which have sprawling legs that stick out to the side). Dinosaurs were reptiles and reproduced by laying eggs. Astrodon was an extremely large reptile. Scientists estimate that an adult Astrodon was at least 60 feet long and weighed several tons. In fact, a six-foot long, 220-pound femur (thighbone) was uncovered at the Muirkirk Deposit in the 1990s confirming Astrodon’s enormous size. In May of 1998 the Maryland State Assembly named Astrodon johnstoni the Maryland State Dinosaur. Please click here for more information about dinosaurs and plants that existed in Maryland during the Early Cretaceous Period.
Why Preserve Dinosaur Park?
The fossil bearing clay of the Muirkirk Deposit at Dinosaur Park is very rare. Hardly anywhere else on the east coast of the United States is there an exposed layer of fossils with dinosaur bones and plant fossils available for scientists to study. Dinosaur bones and teeth, and other fossils enhance our knowledge about prehistoric life and help to explain how plants and animals evolve over time. Dinosaur Park was established for three reasons
Come visit Dinosaur Park and walk the same ground the dinosaurs did millions of years ago and experience the excitement of observing and discovering secrets of Maryland’s prehistoric past! You might just make an important discovery!
For information about school programs and group tours please call 301-627-7755. For general information call 301-627-1286, TTY 301-699-2544.