Astrodon johnstoni DinosaurThe dinosaurs of the Potomac Group are the best known, most abundant, and first ones found in the State. In 1859, only about 17 years after the name “dinosaur” had been coined, Philip Tyson, the State Agricultural Chemist, made available to Dr. Christopher Johnston, a local physician, a strange tooth that he had found in a mine “near Bladensburg”.
Nearly 140 years after its discovery as Maryland’s first known dinosaur, Astrodon johnstoni has been officially named the Maryland State Dinosaur . In 1998, the Maryland General Assembly passed House Bill 1170 and Senate Bill 520 by wide margins. The designation becomes effective October 1, 1998. In the forefront of efforts to get Astrodon named State Dinosaur was Dr. Peter Kranz, local paleontologist, dinosaur hunter and educator.