|The "Capitalsaurus" discovery site, located in Garfield Park at the 100th block of F Street, SE, and named "Capitalsaurus Court" on January 28, 2000. Photo by Nicholas Clark from Wikimedia Commons.|
In January 1898, the centrum of a caudal vertebra from a theropod dinosaur was discovered by J. K. Murphy underneath the streets of the district during an excavation for a sewer line. It was presumably recovered from the Arundel Formation, which made it Aptian in age. This Early Cretaceous fossil (USNM 3049) was given to the Smithsonian Institution, where it remains today.
Although only a fragment of the animal was found, it was still described as its own species and given the name Creosaurus potens by Lull in 1911. This name is more than likely invalid, which means that the name "Capitalsaurus" really has no basis, as it has never been used in the technical literature. Despite this fact, "Capitalsaurus" was still named the official dinosaur of the District of Columbia, and January 28 was designated "Capitalsaurus"Day in 2001 by Mayor Anthony Williams.
Regardless of the taxonomic standing of this particular specimen, I'm certainly not going to pass up an opportunity to celebrate a paleontological holiday, so happy "Capitalsaurus" Day, everyone!
Lull, R. S. 1911. Maryland Geological Survey Stratigraphic Series: Lower Cretaceous; 173-178.