Park History

Although dinosaur discoveries are often associated with the western United States, significant fossils of dinosaurs and other prehistoric animals are also known from the east coast. In the 1800s and early 1900s, the Arundel clays in Prince George’s County were mined for siderite, or iron ore. Iron furnaces located throughout the region melted down siderite to produce iron used in construction and manufacturing. In 1858, African American miners working in open pit mines were the first to discover dinosaur fossils in Maryland.

The group of advanced prehistoric reptiles known as dinosaurs was first recognized in 1842 by British anatomist Richard Owen based on very fragmentary fossils found in England. However, it was not until more complete dinosaur fossils were found in the United States, including in Prince George’s County, that scientists were able to reconstruct the true life appearance and diversity of these extinct animals.

Among the first scientists to explore the Muirkirk deposit in Prince George’s County was geologist Phillip Thomas Tyson. He brought some of the strange bones discovered in the iron mines to a meeting of the Maryland Academy of Sciences in 1859, where his colleagues identified them as dinosaurs. Famous 19th-century paleontologist Othneil Charles Marsh of Yale University was also interested in Maryland fossils. In the winter of 1887, he sent fossil collector John Bell Hatcher to search the iron mines. Hatcher recovered hundreds of fossils, including the remains of ancient turtles, crocodiles, and several dinosaur species. Fossil collecting at the Muirkirk deposit essentially stopped when the iron industry died out in the early twentieth century, but it was revived in the 1980s by paleontologists Peter Kranz and Tom Lipka.

Fossil discoveries continue to happen at Dinosaur Park today. Since October 2009, the Maryland-National Capital Park and Planning Commission has protected the site from development and unrestricted collecting. Dinosaur Park serves as an outdoor laboratory where the public can work alongside paleontologists to help uncover the past. Hundreds of fossils discovered by visitors have been collected and cataloged to date, enhancing our knowledge about the ancient ecosystem that once existed here. Perhaps, you will make an important discovery on your next visit!