Marine biodiversity patterns changed rapidly during the Permian-Triassic mass extinction, altering the latitudinal diversity gradient for 5 million years, according to a study. Species richness increases from the poles to the tropics, a pattern referred to as the latitudinal diversity gradient. The relative influence of factors driving the pattern is unclear. Haijun Song and colleagues explored the mechanisms that control biodiversity patterns, focusing on the Permian-Triassic mass extinction event, which occurred around 252 million years ago. The authors report that marine biodiversity patterns changed rapidly during the mass extinction. The authors analyzed biogeographic distributions using a database of 52,318 records of marine fossils and their locations from the late Permian to the Late Triassic. The latitudinal diversity gradient flattened rapidly at the start of the Triassic, representing a loss of biodiversity in the tropics and an increase in diversity toward the poles. The authors ascribe the loss to extinction due to intense global warming and reduction of oxygen in the ocean--conditions that existed from the tropics to the poles. The curve remained flat for around 5 million years until it gradually began to resemble modern biodiversity patterns. According to the authors, the results support the idea that extreme climate events combined with anthropogenic effects are likely to harm biodiversity in modern ecosystems.
Article #19-18953: "Flat latitudinal diversity gradient caused by the Permian-Triassic mass extinction," by Haijun Song et al.
MEDIA CONTACT: Haijun Song, China University of Geosciences, Wuhan, CHINA; e-mail: haijunsong@cug.edu.cn
###
Proceedings of the National Academy of Sciences