Scientists do research on the plateau in Tibet. (Photo/Courtesy of Nanjing Institute of Geology and Palaeontology of Chinese Academy of Sciences)

The cold and dry plateau of Tibet in Southwest China used to be a warm and humid rainforest 40 million years ago, scientists from China, India and the UK recently discovered, saying that it offers critical evidence of the plateau's ancient environment.

The scientists found a Tibet amber and proved it was the fossil resin of an ancient dipterocarpaceae, the representative plant of Asian rainforests, which is key to proving the existence of Tibet's ancient rainforests, according to a release provided by the Nanjing Institute of Geology and Palaeontology of Chinese Academy of Sciences, which participated in the research, to the Global Times on Thursday.

The Tibet amber, originally located less than 1,300 meters above sea level, is derived from the representative plant of Asian rainforests, said Wang Bo, researcher of the Nanjing Institute of Geology and Palaeontology and program instructor.

Wang's team worked with their counterparts from Britain and India.

At that time, Tibet had a relatively low sea level and so the forest formed because of warm steam from the Indian Ocean, Wang said.

He explained that the Tibet forest resembles Xishuangbanna in Southwest China's Yunnan Province, one of the most famous rainforests in China, which experiences close to tropical climate.