More than 7,600 dinosaur bones have been found in China, a discovery that could help establish why they died out. The find at Zhucheng, in Shandong province, has become known as "Dinosaur City" as a result of bones uncovered there since the 1960s. It is thought to be the biggest in the world and includes the remains of the predator Tyrannosaurus rex and what is thought to be the largest "duck-billed" dinosaur.

Researchers from the Academy of Sciences had unearthed the bones during a dig that began in March. Many of the finds have been dated to the late Cretaceous period when most dinosaurs died out and it is hoped they could shed new light on one of the abiding questions of evolutionary science.

Professor Zhao Xijin, the palaeontologist in charge of the excavations, said: "This group of fossilised dinosaurs is currently the largest ever discovered in the world... in terms of area. The discoveries are expected to contribute to research on the mystery of dinosaur extinction."

The fossil field was found during exploratory mining work. A single pit several hundred metres in length yielded about 3,000 bones.

Paul Barrett, from the Natural History Museum in London, said the claim that the discovery was the "world's largest" was credible.

It is thought the presence of so many bones in a relatively small area could be significant and help scientists work out what caused their sudden disappearance worldwide.

More bones are expected to be uncovered and a paper is expected to be published in a scientific journal this year. Meanwhile, officials in Shandong will work on creating a fossil park that will be open for visitors.