Artist Impression Of Guanlong Wucaii

BEIJING, CHINA - FEBRUARY 13: This artist drawing, which was released by the Institute of Vertebrate Paleontology and Paleoanthropology (IVPP), shows Guanlong Wucaii. A team of scientists led by James M. Clark, Ronald B. Weintraub Associate Professor of Biology at The George Washington University, and Xu Xing of the IVPP in Beijing, have discovered a new genus and species of dinosaur that is the oldest known and most primitive tyrannosauroid. The new basal tyrannosauroid, named Guanlong wucaii, sheds light on the early evolution and geographical distribution of coelurosaurs, small theropod dinosaurs that include the closest relatives of birds. (Drawing by Zhongda Zhang/IVPP via Getty Images)