Yutyrannus

A feathered giant

Yutyrannus was a large, meat-eating relative of Tyrannosaurus, notable for something most tyrannosaurs never show in the fossil record: long, filament-like feathers covering large parts of its body. It grew to about 9 meters, or roughly 30 feet, in length, and may have weighed around 1,400 kilograms, making it one of the largest feathered dinosaurs known. Its skull carried a low bony crest running along the snout, and like other early tyrannosauroids it had three fingers on each hand rather than the two seen in later, larger members of the group.

Its world

Yutyrannus lived during the Early Cretaceous, between about 126 and 120 million years ago, in what is now northeastern China. All known fossils come from a single region, preserved in the Yixian Formation, a rock unit famous for capturing fine details like feathers. It shared this world with the small horned Psittacosaurus, the feathered Sinosauropteryx and Caudipteryx, the raptor Sinornithosaurus, and the early tyrannosauroid Dilong.

How it was found

Xu and his colleagues named Yutyrannus in 2012, based on multiple skeletons found together that preserved patches of feathers. Among dinosaurs with direct fossil evidence of feathers, Yutyrannus is by far the largest yet found, showing that feathered body coverings were not limited to small dinosaurs. Its closest relatives, including Guanlong, Proceratosaurus, and Sinotyrannus, form the family Proceratosauridae, an early branch of the tyrannosauroid line that appeared long before giants such as Tyrannosaurus.