A Mesozoic fossil lagerstätte from 250.8 million years ago shows a modern-type marine ecosystem

years ago shows a modern-type marine ecosystem

Xu Dai1,2, Joshua H. F. L. Davies3 , Zhiwei Yuan1 , Arnaud Brayard2 , Maria Ovtcharova4 ,

Guanghui Xu5,6, Xiaokang Liu1 , Christopher P. A. Smith2 , Carrie E. Schweitzer7 ,

Mingtao Li8 , Morgann G. Perrot3,9, Shouyi Jiang1 , Luyi Miao1 , Yiran Cao1 , Jia Yan1 , Ruoyu Bai10,

Fengyu Wang1 , Wei Guo1 , Huyue Song1 , Li Tian1 , Jacopo Dal Corso1 , Yuting Liu1 ,

Daoliang Chu1 , Haijun Song1 *

Finely preserved fossil assemblages (lagerstätten) provide crucial insights into evolutionary

innovations in deep time. We report an exceptionally preserved Early Triassic fossil assemblage,

the Guiyang Biota, from the Daye Formation near Guiyang, South China. High-precision uranium-lead

dating shows that the age of the Guiyang Biota is 250.83 +0.07/–0.06 million years ago. This

is only 1.08 ± 0.08 million years after the severe Permian-Triassic mass extinction, and this

assemblage therefore represents the oldest known Mesozoic lagerstätte found so far. The

Guiyang Biota comprises at least 12 classes and 19 orders, including diverse fish fauna and

malacostracans, revealing a trophically complex marine ecosystem. Therefore, this assemblage

demonstrates the rapid rise of modern-type marine ecosystems after the Permian-Triassic

mass extinction.