Astrodon (meaning "star-tooth") was a long-necked plant-eating dinosaur, a relation of "Brachiosaurus". The sauropod was about 30 feet (9 m) long. It lived during the Lower Cretaceous period, about 130 million to 120 million years ago. "Astrodon" is known from teeth and scattered bones found in Maryland. Astrodon is the state dinosaur of Maryland. "Astrodon" was named by Johnston in 1859. The type species is "A. johnstoni". "Astrodon" may be the same as "Pleurocoelus".