Guanlong

Guanlong was a small, early tyrannosaur that lived approximately 160 million years ago in what is now northwestern China. Despite being an ancestor of the mighty Tyrannosaurus rex, Guanlong was a modest predator standing only about waist-high to a human. Its most striking feature was a large, fragile crest running along the top of its skull — so thin and delicate it couldn't have been used for combat, suggesting it was purely for display or species recognition.

This dinosaur was a nimble, bipedal carnivore with relatively long arms tipped with three-fingered hands — quite different from the stubby two-fingered arms that would later evolve in its giant descendants. Guanlong likely hunted small prey in the lush Jurassic forests and lakesides of the Shishugou Formation, an ecosystem that also harbored early mammals, pterosaurs, and other theropods.

Guanlong was described in 2006 by renowned Chinese paleontologist Xu Xing and colleagues, based on two remarkably complete specimens discovered in the Junggar Basin of Xinjiang, China. The fossils include an adult found lying atop a juvenile in a death assemblage, possibly victims of a muddy trap. This dramatic discovery gave scientists rare insight into how these animals grew.

The name Guanlong means 'crowned dragon,' referring to its elaborate head crest, while the species name 'wucaii' honors the colorful Wucaiwan locality where it was found — the name meaning 'five colors' in Chinese.