The recovery of life from the devastating end-Permian mass extinction, which peaked about 252.3 million years ago, was an important period of evolution. Whether biodiversity had to rebuild from near annihilation or from refugia is a matter of conjecture but recovery heralded the development of recognizably modern ecosystems. Paleontologists have now discovered an exceptionally preserved fossil assemblage in the Daye Formation near Guiyang, China. Named Guiyang Biota, the assemblage is dated to 250.83 million years ago (nearly one million years after the extinction event) and presents examples of diverse fishes, ammonoids, bivalves, protists, and malacostracan arthropods.
The end-Permian mass extinction, also known as the Permian-Triassic extinction event and the Great Dying, is the most severe extinction event in the past 540 million years.
This catastrophe, which peaked about 252.3 million years ago, killed off nearly 96% of all marine species and 70% of terrestrial vertebrate species on the planet over the course of thousands of years
Massive eruptions in a volcanic system called the Siberian Traps are thought to have played an important role, but the causational trigger and its feedbacks are yet to be fully understood.
The recovery of marine life following the extinction and during the Early Triassic epoch is widely considered to be a major period of evolutionary changes that laid the foundation for the ecosystems that dominate oceans today.
However, due to the relative scarcity of marine fossils dating back to this critical period, the evolution of marine biota in the wake of the mass extinction is poorly understood.
“The fossils of the Guizhou region reveal an ocean ecosystem with diverse species making up a complex food chain that includes plant life, bony fish, ray-finned fish, crabs, lobsters, shrimp, and mollusks,” said Dr. Morgann Perrot, a paleontologist at the Université du Québec à Montréal.
“We discovered 12 classes of organisms and…
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