Beijing, Bolong.id – The results of research by Chinese scientists reveal the process of development of marine animals since the mass extinction 250 million years ago.
Reported from People’s Daily Online, Tuesday (07/02/23), the research was published Friday (3/2/2023) in the journal Science. Depicts a collection of preserved fossils excavated in Guiyang, southwest China’s Guizhou Province.
The assemblage represents the oldest known lagerstatte, or sedimentary deposit that exhibits superbly preserved fossils, and demonstrates the rapid increase in robust, modern-type marine ecosystems.
The Great Dying occurred about 252 million years ago and is believed to be the most severe extinction event on Earth.
It wiped out more than 80 percent of marine species, taking the worst toll on sessile organisms in the oceans and making room for organisms to move.
But how quickly new ecosystems with complete pyramid structures, including predators and prey, emerge on stage is poorly understood due to the dearth of well-preserved fossils, according to the study.
A group of paleontologists led by Song Haijun of China University of Geosciences, Wuhan, discovered the rarely seen fossilized lobster fragments in early 2015, before they began their eight-year excavation project.
Their ongoing fieldwork has uncovered an unprecedented portrait of ancient animals comprising at least 12 classes and 19 orders, uncovering complex marine ecosystems including a wide variety of fish and crab-like animals.
The new assemblage includes several representative species ranging from 100-micron primary consumers to meter-long predatory fish, as well as abundant dung fossils, which made up the complex food chains and complete ecological structures of the time.
The scientists used high-precision U-Pb dating and revealed that, despite the harsh marine environment, this ecosystem emerged only about 1 million years after a severe extinction event, earlier than previously believed.
This fills a three million year gap in complex marine fauna, according to the study.
“Although the Guiyang Biota has still not been completely sampled, this highlights that the slow and gradual recovery model is not applicable to the period after this mass extinction,” said Song.
The period after the Great Death is often described as an extremely hot world where tropical life was driven to the poles, but new findings from the Guiyang Biota hint at a cooling gap in the tropics without lethal heat, and this gap supported the growth of marine systems in that region, according to the study. .
This study “provides us with new insights into the rate and nature of life recovery after this largest mass extinction,” said one of the paper’s reviewers.
“In the future, Guiyang Biota will surely be able to provide more surprises to provide clues about the origins of modern marine ecosystems,” said Song, the paper’s corresponding author.
