Scientists unearth the grandaddy of Tyrannosaurus rex
By Mark Henderson
A small, crested dinosaur that may be the ancestor of Tyrannosaurus rex has been discovered in China, scientists said yesterday.
Guanlong wucaii, the “crowned dragon of the five-coloured rocks”, lived in the late Jurassic period about 160 million years ago, making it the earliest known forerunner of the tyrannosaurs, which had been considered the oldest member of the dinosaur family.
The newly identified dinosaur was much smaller than its later relative, growing to about three metres (10ft) from head to tail. The largest known tyrannosaur specimens were significantly bigger, reaching up to 13m (42ft) in length. Guanlong wucaii, however, boasts several anatomical features that clearly mark it out as a primitive tyrannosauroid — the group that includes Tyrannosarus rex and other great predators of the later Cretaceous period, such as Giganotosaurus and Gorgosaurus. Tyrannosaurus lived between 85 million and 65 million years ago.
Two skeletons belonging to the creature, one almost intact, were unearthed by a team led by Xing Xu, one of the world’s most successful fossil hunters, of the Institute of Vertebrate Palaeontology and Paleoanthropology in Beijing. Details of the finds are published today in the journal Nature.
The discovery, in the Wucaiwan area of the Junggar Basin in the Xinjiang province, offers new insights into the evolution of the tyrannosauroids, fleshing out the “tyrant king’s” family tree.
It has the characteristic enlarged skull, powerful hind legs, stubby forelimbs and blade-like teeth of the group. Guanlong wucaii is also remarkable as it has a large, spectacular crest on its skull. The feature has surprised scientists, as it is highly fragile and would have been a considerable handicap to a predatory species.
Dr Xing said that the likeliest explanation for the crown was as an ornament used in sexual signalling. He likened it to the elaborate tail of peacocks.
First Jurassic dromaeosaurs and now a Jurassic tyrannosaur. *swoons*