Meet Astrodon johnstoni

Meet Astrodon johnstoni. The Maryland State Dinosaur. , Astrodon was a member of the group of long necked, plant-eating dinosaurs called sauropods. When fully grown, it may have exceeded 60 feet in length and weighed 20 tons., Astrodon was discovered in 1858, right here in Prince George's County. It was the first dinosaur found in Maryland and one of the first dinosaurs to be scientifically described., In 1998, The Maryland General Assembly named Astrodon the Maryland State Dinosaur. Astrodon joins other iconic state symbols like the Blue Crab, Black-Eyed Susan and Baltimore Oriole., Putting the Bones Together , Astrodon is the most completely known Maryland dinosaur. Most Astrodon fossils come from horse-sized juveniles, but a few bones including a 6-foot femur (thigh-bone), confirm that the adults were truly gigantic., All Astrodon bones discovered so far are shown here., Johnston's Star Tooth , In 1858, geologist Phillip Tyson brougth some fossil teeth recovered in a Prince George's county iron mine to the Maryland Academy of Sciences. Academy member (and dentist) Christopher Johnston recognized the teeth as similar to those of the dinosaurs that had recently been discovered in Europe. Johnston named the animal Astrodon, meaning star tooth, because the teeth have a starburst shape in cross section., Leading 19th century naturalist Joseph Leidy published this drawing of the original Astrodon teeth in 1865., Growing Up Dinosaur , Elephants and other big modern mammals invest lots of time and energy into one baby at a time. Auropods were different. They laid dozens of eggs and then abandoned them to their fate. Each baby was unlikely to survive to adulthood, but there were so many that some of them made it. Because they were not burdoned by the need to give live birth, sauropods could grow bigger and faster than elephants., How do We Know? , Like most dinosaurs, Astrodon is known only from isolated, often fragmentary bones. Fortunately, Maryland fossils do not exist in a vacuum. We can compare Astrodon fossils to more completely known relatives. Scientists' reconstructions of Astrodon are based in part on the remnants of Brachiosaurus from Colorado and Giraffatitan from Tanzania.