MEET the sixth member of the Tyrannosaurus family -- the 11 metre long "little" cousin of T-Rex.
A new dinosaur species closely resembling the famous predator has been discovered in China by an Irish biologist.
Dr David Hone, a lecturer at UCD's School of Biology and Environmental Science, headed an international team of scientists -- including one of the world's foremost palentologists -- who recently identified the new dinosaur.
Their findings will be published today in the scientific journal "Cretaceous Research".
The new dinosaur was named 'Zhuchengtyrannus magnus', after the area in Shangong province in eastern China where the remains were found.
Based on the partial skull and jawbones found, scientists believe the creature would have measured 11 metres long, stood four metres high and weighed almost six tonnes -- comparable in size to the infamous T-Rex.
It is also believed to be one of the largest predatory carnivores ever identified by scientists.
Along with the T-Rex and the Asian Tarbosaurus, the new species joins an elite club of gigantic dinosaurs called tyrannosaurines that are believed to have roamed throughout North America and eastern Asia during the late Cretaceous Period between 65 and 99 million years ago.
They were gargantuan beasts characterised by huge bone-crushing jaws, small arms and two-fingered hands.
"With only some skull and jawbones to work with, it is difficult to precisely gauge the overall size of this animal," said Dr Hone (32).
"But the bones we have are just a few centimetres smaller than the equivalent ones in the largest T-Rex specimen. So there is no doubt that Zhuchengtyrannus was a huge tyrannosaurine."
He said that the new dinosaur can be distinguished from other tyrannosaurines by a combination of unique features in the skull.
"We named the new genus Zhuchengtyrannus magnus -- which means the 'Tyrant from Zhucheng' -- because the bones were found in the city of Zhucheng," he added.
The quarry in which the new species was found has proved to be a treasure trove of dinosaur bones, and boasts one of the world's largest concentrations of dinosaur fossils in the world.
This is due to its location on a large flood plain where many dinosaur bodies were washed together and fossilised.
Professor Xu Xing of the Beijing Institute of Vertebrate Paleontology and Paleoanthropology, who was a key researcher on the team, is alone credited with identifying 30 new dinosaur species.
But finding a new species of tyrannosaurine was truly special, Dr Hone said.
"There's was only five of them and this is now the sixth."
And the fact it was found at all was a bit of a fluke.
Builders were pouring a foundation for a fossil museum at the site when "they found a big bit of teeth sticking out of the ground," he said.
The building work was halted and excavations turned up a dinosaur's partial skull, as well as the partial skull of another species and various bones.
"It's a shame there's not more of it," he said.
"We've probably got half a skeleton there but we can't prove it."