Nearly a hundred new animal species survived a mass extinction event half a billion years ago They were found in a small quarry Chinascientists reported on Wednesday.
The treasure trove of fossils provides a rare glimpse into a cataclysmic event that abruptly ended the largest burst of life in our planet’s history.
Han Zeng of the Chinese Academy of Sciences told AFP the site where the fossils were found in southern China’s Hunan province was “extraordinary”.
“We collected more than 50,000 fossil specimens from a single quarry measuring 12 meters high, 30 meters long and eight meters wide,” added the lead author of one. new study in the journal Nature.
In that small space, the Chinese team discovered more than 150 different species—91 of which are new to science—between 2021 and 2024.
Han described the “wonderful experience when we realized those animals were right there on the rock.”
“Many fossils show soft parts, including gills, guts, eyes and even nerves,” he added.
Han Zeng/Handout via REUTERS 
Among the species found were ancient relatives of worms, sponges and jellyfish.
They also found many arthropods—a family that includes modern-day crabs and insects—including spiny, stalk-eyed creatures. radiodonts who were the apex predator of the time.
The discovery is particularly exciting for scientists because of the time in which these rare animals lived.
Evolution’s big bang
Life originated on Earth more than 3.5 billion years ago, but it was only a layer of mud for much of our planet’s history.
Then he came Cambrian explosion, known as the “big bang” of evolution, approximately 540 million years ago. Suddenly, most of the major groups of animals alive today—including the vertebrates that would eventually include humans—evolved and began to populate the world’s oceans.
This explosion of life is thought to have been fueled by the rise of oxygen in the Earth’s atmosphere.
However, it ended abruptly 513 million years ago when half of all animals died out. This mass extinction, known as the Sinsk event, is thought to have been caused by a drop in oxygen levels.
The animals from the Chinese quarry, dated to about 512 million years ago, are the first major discovery of soft-bodied fossils that lived directly after the Sinsk event, Han explained.
This means that the fossils – discovered in the county called Huayuan biota – “open a new window on what happened”, he added.
“We were surprised”
Michael Lee, an evolutionary biologist at the South Australian Museum who was not involved in the research, said, “The new fossils from China demonstrate that the Sinsk event affected shallow water forms most severely.”
Called deep water fish selacanto it also survived the mass extinction that wiped out all dinosaurs that didn’t evolve into birds, he noted.
“The deep ocean is one of the most stable environments over geological time, similar to how it protects a house’s cellar from daily and seasonal changes, and has less temperature fluctuations than an attic,” Lee told AFP.
There he said his team was also surprised to find some of the animals from the quarry in Canada as well Burgess Shale site, dating back to the beginning of the Cambrian explosion.
This suggests that these animals were able to travel halfway around the world at this early stage, he added.
“We were surprised to find that the Huayuan biota shared several animals with the Burgess Shale, including the arthropods Helmetia and Surusicaris previously known only from the Burgess Shale.” Zeng told Reuters. “Because larval stages are common in modern marine invertebrates, the best explanation for these shared taxa is that early animal larvae were able to be dispersed by ocean currents from early Cambrian animal times.”
The Sinsk event is not considered among the most famous “Big Five” mass extinctions in our planet’s history.
Han said there is evidence of 18 or more mass extinctions in the last 540 million years, and called for more attention to be paid to the extremely destructive events.
Scientists have long debated whether dinosaurs were on the decline the asteroid hit the Earth 66 million years ago, causing a mass extinction. Recent research suggests that they were dinosaur populations it is still growing in North America before the asteroid hit.
A research group in 2019 found that the steroid attack had sparked a chaotic day of fires, earthquakes and tsunamis, leading to a prolonged period of global cooling.