Guanlong

Guanlong was an early member of the tyrannosauroid lineage that roamed north-western China during the Late Jurassic period, roughly 160 million years ago. Reaching about three metres in length, it was an agile, bipedal carnivore with three-fingered grasping arms and slender hind legs. Its most striking anatomical feature was a prominent, wafer-thin crest running along the midline of its snout. Highly fragile and filled with pneumatic cavities, this crest would have broken easily in combat, pointing towards a role in sexual display or species recognition rather than defence. Two specimens were famously found trapped one atop the other in deep mud pits created by the footsteps of sauropods. Guanlong demonstrates that the earliest relatives of Tyrannosaurus rex were swift, crested hunters that occupied middle predator niches long before conquering the apex role.

It possessed a remarkably large, delicate, air-filled bony crest running along the top of its snout.

Where and when

Guanlong lived in the Late Jurassic, from 161 to 159 million years ago (Oxfordian age). Its remains come from China, in the Shishugou Formation.

The numbers

Length 3.1 m (estimates run from 3 to 3.2 m). Mass about 84 kg. Hip height about 1 m. That is 1.8 human-lengths, or 0.28 of a double-decker bus. These are estimates from near-complete skeleton; fields marked estimated by the site are length, mass, hip height.

Compare Guanlong with a bus Place on the timeline