Guanlong

Guanlong (冠龍) is a genus of extinct proceratosaurid tyrannosauroid dinosaur from the Late Jurassic of China. The taxon was first described in 2006 by Xu Xing et al., who found it to represent a new taxon related to Tyrannosaurus. The name is derived from Chinese, translating as "crown dragon". Two individuals are currently known, a partially complete adult and a nearly complete juvenile. These specimens come from the Oxfordian stage of the Chinese Shishugou Formation. Guanlong was discovered in the Dzungaria area of China by a joint expedition by scientists from the Institute of Vertebrate Paleontology and Paleoanthropology and George Washington University, and named by Xu Xing and others in 2006. Guanlong comes from the Chinese words for "crown", 冠, and "dragon", 龍, referring to the crest. The specific epithet (五彩), wucaii (Hanyu Pinyin: wǔcǎi), means "multicoloured" and refers to the colours of rock of the Wucaiwan (五彩灣, "5-colored bay", "multicolored bay"), the multi-hued badlands where the creature was found. At present, Guanlong is known from two specimens, one discovered on top of the other, with three other individual theropod dinosaurs, in the Shishugou Formation. The holotype (IVPP V14531) is a reasonably complete, partially articulated adult skeleton, and was the one on top. Another, immature specimen, the paratype IVPP V14532, is known from fully articulated and nearly complete remains. It was presumed to have been trampled, after death, by the adult. The crest on the skull of the immature specimen is notably smaller and restricted to the forward portion of the snout, while the adult has a larger and more extensive crest. The crests of both specimens are thin, delicate structures that likely served as display organs, possibly for events like mating. Guanlong was a relatively small theropod, reaching in length and in body mass. Its fossils were found in the Shishugou Formation dating to about 160 million years ago, in the Oxfordian stage of the Late Jurassic period, 92 million years before its well-known relative Tyrannosaurus.