A Chinese scientist has failed in his attempt to stop an auction house in the United States from selling a rare fossilized dinosaur nest he believes may have been smuggled out of China.

The unusually well-preserved 65 million-year-old nest containing fossilized eggs was sold yesterday for US$420,000 by Los Angeles auction house Bonhams & Butterfields.

Prior to the sale, Xing Lida, a dinosaur expert at the Chinese Academy of Sciences, appealed to Bonhams to halt the fossil's auction.

US media reported that the nest - believed to have belonged to a raptor - was unearthed in south China's Guangdong Province in 1984.

The nest contains 22 unhatched eggs arranged in a circular pattern. Embryonic remains were discovered in 19 eggs, and one egg was removed for study. Some eggs were so well-preserved that the embryo curled inside was still visible.

Bonhams has refused to reveal the identity of the buyer.

Earlier reports said the original collector had hoped the fossil would be bought by a museum. But experts warned that, due to current high interest among private collectors and financial constraints facing museums, the fossil would most likely fall into private hands.

"I am worried about the fossil's fate," Xing said.

"The well-preserved dinosaur embryos are rare, and many Chinese scientists have seen such fossils only in pictures. The fossil will lose its scientific value in the hands of private collectors."

Gerald Grellet-Tinner, a dinosaur expert at the South Dakota School of Mines and Technology, told reporters that the fossilized nest was a "bonanza" that could tell scientists a great deal about dinosaur growth and development.

He argued the nest should be housed in a museum in China, where it was discovered, and not in private hands.

The theft and smuggling of fossils is a serious problem in China. Smugglers have often broken fossils to make them easier to conceal and carry.

Xing said that apart from a few local regulations China has no laws to protect fossils. He said he and fellow Chinese experts are urging the authorities to draft new laws to increase fossil protection.