Beijing, Nov 22 (IANS): Chinese archaeologists have found molecular evidence of the protein keratin in a bird fossil from the Cretaceous Period 130 million years ago, which may provide clues about the colour of feathered dinosaurs and early birds.

The research paper by experts with the Nanjing Institute of Geology and Palaeontology was published by America's Proceedings of the National Academy of Sciences on Tuesday, Xinhua news agency reported.

Pan Yanhong, a leading researcher with the programme, said they discovered the molecular structure of a protein that determines feather colour in the bird fossil.

According to the study, these molecular structures are preserved in fossils and are consistent with modern feathers.

Researchers hope the study will lead to hypotheses about dinosaur colour, behaviour, habitat and physiology.

It was the oldest molecular evidence found in bird fossils. Previously, the molecular structure of the protein had only been found in fossils dating back some 80 million years.

The bird that experts used in the research is one of the earliest fossils found in China.

The Cretaceous bird, named Eoconfuciusornis, was discovered in north China's Hebei province in 2008.