As growing numbers of species in the modern world face extinction because of global climate change, habitat destruction, and over-exploitation, scientists have turned to the fossil record to understand how mass extinctions in the past proceeded, and how species and ecosystems recovered in the aftermath of such events.
Much work so far suggests that the survivors of mass extinctions often are presented with new ecological opportunities because the loss of many species in their communities allows them to evolve new lifestyles and new anatomical features as they fill the roles vacated by the victims.
However, it turns out that not all survivors respond in the same way, and some may not be able to exploit fully the new opportunities arising after a mass extinction. A team of researchers from the University of Lincoln, the Field Museum of Natural History in Chicago, the Museum für Naturkunde in Berlin, and the University of Bristol examined how a group of ancient relatives of mammals called anomodonts responded in the aftermath of the largest mass extinction in Earth history. Their work, published this week in Proceedings of the Royal Society B and titled “Decoupling of morphological disparity and taxic diversity during the adaptive radiation of anomodont therapsids”, shows that anomodonts remained anatomically conservative even as the number of species rebounded during the recovery.
Plot of number of species and anatomical diversity of anomodonts through time. From left to right, the four anomodont skulls belong to Suminia getmanovi (Late Permian of Russia), Compsodon helmoedi (Late Permian of Zambia), Lystrosaurus murrayi (Early Triassic of South Africa) and Kannemeyeria simocephalus (Middle Triassic of South Africa). Photo credits: Suminia, Diane Scott and Robert Reisz (University of Toronto, Mississauga, Canada); Compsodon, Lystrosaurus and Kannemeyeria, Kenneth Angielczyk (Field Museum of Natural History, Chicago, USA).
Read more at: Phys.org