The recovery of marine fauna after the mass extinction of the Permian-Triassic, approximately 252,000,000 years ago, there was much faster than specialists believedAccording to an article published in the Science Magazine.
The thing is. although until now it was expected that, as a consequence of the practically non-existent biodiversity survivorbiotic recovery had been very slow, calculating that it took a few 8,000,000 yearsA recent study states that his recovery took much less time.
To carry out the study, the team scientists investigator led xu daifrom the School of Earth Sciences of the University of Geosciences of China, explored the so-called Guiyang Biota, a set of marine fossils from the lower Triassic that is perfectly preserved in the Daye Formationlocated in south china.
“This set, dating from 250.8 million years ago, represents one of the lagerstätte —term used to designate those paleontological sites with a great wealth of fossils— of the Mesozoic oldest known and proportional an unprecedented snapshot of a marine ecosystem just a million years after the great extinctionón”, explained the scientist in an interview with SYNC.
“Not alone causing a grave decline in diversitybut also triggered the transition from the evolutionary fauna of the Paleozoic to the modern. The Guiyang Biota tells us that this transition occurred nimbly. A million years in geological history is fast,” Dai added.
Furthermore, while the scientists found several Triassic biotas dating from about 3,000,000 years after the great extinction occurred, the Guiyang Biota has shown to have a much closer antiquity to that event, which represents a highly diversified and ecologically complex marine ecosystem.
“We obtained its numerical age using the high-precision U-Pb dating technique. in zircon grains found in the fossil interval. This rapid recovery of the fauna in the Early Triassic is shown with poorly diversified fossil assemblages and dominated by one or two taxa, which are called opportunistic taxa”said the study leader.
“To date, we have found 40 species representing at least 19 orders, from predators very large, such as the coelacanth, one meter long, to very small organisms, such as foraminifera. the main evolutionary change It would have been that they are more diversified in the modern oceans, except for the ammonoidsthey had bad luck and became extinct at the end of the CretaceousTogether with the non-avian dinosaursDai recounted.
From now on, Dai and his team of collaborators will try to investigate not the origin of the cause of the mass extinction of marine fauna, but also its terrible consequencessome of which are still a great mystery for science.
“Our research refutes the stepped trophological recovery model, try the rapid emergence of the type marine ecosystemand downgrades the trophic dead zone hypothesis by filling, at least partially, the gap of vertebrates fossils paleotrophic from the Early Triassic,” Dai concluded.
