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Last Updated: Friday September 18 2009 13:49 GMT

Mini T Rex ancestor discovered

The skull of Raptorex kriegsteini is dwarfed by the skull of a full-sized T Rex (Photo: Paul Soreno)

Tiny T Rex relative uncovered

A 3m-long dinosaur skeleton unearthed in China was an early mini-version of the Tyrannosaurus Rex, say scientists.

The new Raptorex kriegsteini species, was around 60 million years before the T Rex and was tiny compared to its later cousin, weighing only 65kg.

But experts think it could be the missing link between the T Rex and earlier species of dinosaur.

The skeleton suggests the T Rex's big head, small forearms and huge back legs were inherited from the Raptorex.

It's also led them to believe the body type of dinosaurs has hardly changed over the years, except in size.

Quiz
The Raptorex skeleton

Over the past 10 years, fossils from earlier dinosaur species have been found in rocks between 100 and 176 million years old in Europe, North America and China.

The findings have confirmed that the Tyrannosaur family of dinosaurs comes from small-armed and long-bodied predecessors.

But, until now, there's been little evidence of a direct link between those dinosaurs and the huge T Rex.

Tiny T Rex relative is unearthed

Lead researcher Dr Paul Soreno, from the University of Chicago, said: "It's as close to the proverbial missing link on a lineage as we might ever got for T Rex.

"From the teeth to the enlarged jaw muscles, the enlarged head, the small forelimbs, the lanky, running, long hind-limbs with the compressed foot for hunting prey: we see this all, to our great surprise, in an animal that is basically the body weight of a human or 1/90th the size that ultimately this lineage would reach in T Rex at the end of the Cretaceous [period]."