Yutyrannus

Yutyrannus is an extraordinary tyrannosauroid theropod discovered in Liaoning Province, China, dating to the Early Cretaceous period. Known from three exquisitely preserved skeletons representing both adults and juveniles, it holds the record as the largest animal known to possess direct, fossilised evidence of feathers. These simple, filamentous down-like structures reached up to twenty centimetres in length, probably providing thermal insulation in the cool, temperate climate of the ancient Yixian ecosystem. Reaching around nine metres in length and over a tonne in weight, Yutyrannus was the undisputed top predator of its environment. Its skull was ornamented with a distinctive, wavy midline crest, used perhaps for display or species recognition. Its discovery definitively proved that even large-bodied predatory dinosaurs could be generously clad in plumage.

It is the largest known animal with direct fossil evidence of feathers.

Where and when

Yutyrannus lived in the Early Cretaceous, from 125 to 124 million years ago (Aptian age). Its remains come from China, in the Yixian Formation.

The numbers

Length 8.8 m (estimates run from 8.5 to 9 m). Mass about 1.3 t. Hip height about 2.7 m. That is 5.2 human-lengths, or 0.79 of a double-decker bus. These are estimates from near-complete skeleton; fields marked estimated by the site are length, mass, hip height.

Compare Yutyrannus with a bus Place on the timeline