Ancient biotic group discovered in Guiyang

A lobster fossil fragment found in the biotic group in Guiyang [Photo/Dongjing news]

According to China University of Geosciences in Wuhan, Central China's Hubei province, professor Song Haijun and his team found a biotic group that can be dated back to 250.8 million years ago in Guiyang, capital of Southwest China's Guizhou province.

The research was published in Science magazine on Feb 10. Guiyang's biotic group is the oldest known Mesozoic special buried fossil pool, and came into existence only about 1 million years after the most catastrophic Permian-Triassic extinction.

The reviewers of the Science believe that the discovery can provide a better understanding of the manner and speed at which life recovered after the largest known extinction.

Song said that the discovery started from a field survey in the spring of 2015, when his student Dai Xu found a very strange lobster fossil fragment in a piece of black shale, which caught the attention of the team and led to the discovery of more fossils.

To figure out the precise age and biological features of the biotic group found in Guiyang, Song and his team carried out a large amount of geological work in the area and conducted systematic research into paleontology, biostratigraphy, chronostratigraphy, sedimentology, and sedimentary geochemistry.

Song and his team have tentatively clarified the main features, stratigraphic distribution, burial age and burial environment of the biotic group.

So far, 40 different species of animals and coprolites were found in the biotic group, indicating that the food web and ecological structure were relatively complex and complete at that time.

"This discovery shows that the ecological reconstruction after the Permian-Triassic extinction was faster than we thought," said Song. It helps scientists better understand the evolutionary relationship between organisms and the environment under extreme climatic conditions.