Rise of the bottom feeders! Worms and shrimp were the first animals to recover after the “Great Dying” mass extinction that nearly wiped out life on Earth 252 million years ago, the study finds
- Animals feeding on organic matter on the seafloor recovered first after the Great Dying
- That’s the finding of a new study by researchers from China, the US and the UK
- The Great Dying mass extinction event occurred on Earth 252 million years ago
- However, life recovered, and shrimp and worms were among the first to recover
According to a new study, worms and shrimp were among the first animals to recover after the ‘Great Dying’ mass extinction that nearly wiped out life on Earth 252 million years ago.
Researchers said reservoir feeders — creatures that feed on organic matter that settled at the bottom of the ocean — were the first to recover in terms of population numbers and biodiversity.
The mass extinction event at the end of the Permian wiped out 90 percent of species on Earth, and it took millions of years for biodiversity to return to pre-extinction levels.
But by studying trails and caves on the South China seabed, the international team of researchers was able to piece together the revival of marine life by pinpointing exactly what animal activity was happening and when.
Shrimp and worms were among the first animals to recover after the “Great Dying” mass extinction that nearly wiped out life on Earth 252 million years ago, according to a study. This graphic shows what the oceans might have looked like before (A) and after (BF) the extinction
TIMETABLE WHEN ANIMALS BEGAN TO RECOVER AFTER THE ‘GREAT DYING’
Deposit feeders, including shrimp and worms, were the first to recover after the Great Dying. They did this about 251 million years ago.
Next came the recovery of suspension feeders, which snack on organic matter suspended in water.
Corals came back even later.
About 3 million years after the reservoir feeders’ recovery – about 248 million years ago – the soft-bodied sediment dwellers also returned to pre-extinction levels.
Professor Michael Benton of the University of Bristol’s School of Earth Sciences said: “The late Permian mass extinction and early Triassic recovery of life are very well documented across southern China.
“We were able to look at trace fossils from 26 sections of the entire series of events, representing seven million crucial years, and showing details at 400 sampling sites, we finally reconstructed the recovery stages of all animals including benthos, nekton, etc. as well as these soft-bodied, ocean-burrowing animals.” ‘
Recovery from suspension feeders, which snack on organic matter suspended in water, followed much later than depot feeders, according to the study.
Corals came back even later, while it took about 3 million years for soft-bodied sedimentary dwellers to return to pre-extinction levels.
The study examined a large number of ichnofossils, or trace fossils – which are not actual animal remains, but are remains of animal activity.
dr Xueqian Feng of the China University of Geosciences in Wuhan said: “Trace fossils such as trails and caves mainly document soft-bodied animals in the sea.
“Most of these soft-bodied animals had no or poor skeletons.
“There are some amazing places in southern China where we find large numbers of beautifully preserved trace fossils, and the details can show the behavior of ecosystem engineering in fauna as well as their feedback effects on skeletal animal biodiversity.”
Researchers said reservoir feeders like shrimp (pictured) — creatures that feed on organic matter that settled on the ocean floor — were the first to recover in terms of population numbers and biodiversity
Professor Zhong-Qiang Chen, who led the study, said: “The trace fossils show us when and where soft-bodied, burrowing animals flourished in this early Triassic greenhouse world.
“For example, elevated temperatures and widespread anoxia coincided with low levels of behavioral and ecological differences across the Permian-Triassic boundary, and it took about 3 million years for the ecological recovery of soft-bodied animals to return to pre-level levels equated to extinction.”
Alison Cribb, a University of Southern California collaborator on the study, added: “The first animals to recover were reservoir feeders like worms and shrimp.
“Recovery of suspension feeders such as brachiopods, bryozoans, and many bivalves took much longer.
“Perhaps the sediment promoters messed up the seabed in such a way that the water was polluted with silt, the mud being thrown up meant the suspension feeds couldn’t settle properly on the seabed, or the muddy water produced by these sediment promoters just clogged.” the filter structures of suspension feeders and prohibited them from feeding efficiently.’
Climate change, global warming, declining oxygen levels, and increasing ocean acidification are thought to be the primary causes of the “Great Dying” mass extinction.
The study was published in the journal Science Advances.
WHAT WAS THE PERMIAN MASS EXTINCTION KNOWN AS “THE GREAT EXTINCTION” WHICH KILLED 9 OUT OF EVERY 10 SPECIES?
About 248 million years ago the Permian ended and the Triassic began on Earth.
The border between these two geological epochs marks the Permian mass extinction, nicknamed “The Great Dying”.
Almost all life on earth was wiped out in this cataclysmic event.
Scientists believe that around 95 percent of all marine life perished during the mass extinction, and less than a third of life on land survived the event.
Overall, it is believed that 90 percent of all life has been wiped out.
All life on Earth today descends from the approximately 10 percent of animals, plants, and microbes that survived the Permian mass extinction event.
It was previously thought that a huge eruption blanketed the Earth in thick smog and blocked the sun’s rays from reaching the planet’s surface.
However, new evidence suggests that a massive volcanic eruption lasting nearly a million years released a vast reservoir of deadly chemicals into the atmosphere that have been stripping the Earth of its ozone layer.
This wiped out the only protection earthlings had against the sun’s deadly UV rays.
This high-energy form of radiation can severely damage living organisms and skyrocket the death toll.