The ups and downs of biodiversity after mass extinction

The climate after the largest mass extinction to date 252 million years ago was initially cool, later very warm and then cool again. Thanks to the cooler temperatures, the diversity of marine fauna increased significantly, as paleontologists have been able to reconstruct. The warmer climate, combined with a high CO2 content in the atmosphere, initially led to new short-lived species. In the longer term, however, this climate change had a negative impact on biodiversity and caused species extinction. It was previously assumed that fauna and flora recovered only slowly after the huge extinction of species at the end of the Permian period 252 million years ago. According to doctrine, complex ecological communities did not typically reappear until the Middle Triassic, 247 million years ago. Now a Swiss team led by palaeontologist Hugo Bucher from the University of Zurich has shown that marine animal groups such as ammonoids and conodonts (microfossils) reached their first peak three to four million years earlier, i.e. in the Lower Triassic.