A study examines factors leading to the end-Permian mass extinction on land. The greatest mass extinction on Earth occurred at the end of the Permian period, approximately 252 million years ago. However, there are few quantitative investigations of the extinction's impact on land animals. Pia Viglietti and colleagues analyzed 588 fossil land vertebrate specimens from the Karoo Basin, South Africa. The fossils spanned approximately 4 million years, encompassing the time of the end-Permian extinction. The authors categorized species occurrences into 13 rock unit bins, each representing an average time-interval of 300,000 years. High extinction rates initially co-occurred with low origination rates, leading to overall ecosystem instability and rapid turnover of short-lived species. High extinction rates continued for approximately 1 million years, up to the extinction peak near the boundary between the Permian and Triassic periods. The long duration of terrestrial extinction contrasts with the shorter extinction event recorded in ocean ecosystems. While overall species richness remained low, the ancient mammal relative Lystrosaurus was abundant and experienced population peaks both before and after the identified acme of the end-Permian extinction. The findings suggest that the success of Lystrosaurus was not fostered by ecological expansion following the extinction of other species, as hypothesized previously, but rather via advantageous environmental changes resulting from climate fluctuations, according to the authors.
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Article #20-17045: "Evidence from South Africa for a protracted end-Permian extinction on land," by Pia A. Viglietti et al.
MEDIA CONTACT: Pia A. Viglietti, Field Museum of Natural History, Chicago, IL; tel: 773-782-7211; email: < pviglietti@fieldmuseum.org >; Roger B. J. Benson, University of Oxford, UNITED KINGDOM; email: < roger.benson@earth.ox.ac.uk >; Kenneth D. Angielczyk, Field Museum of Natural History, CHICAGO, IL; email: < kangielczyk@fieldmuseum.org >
Proceedings of the National Academy of Sciences