Nav: Home

Discovery of a new mass extinction

September 16, 2020

It's not often a new mass extinction is identified; after all, such events were so devastating they really stand out in the fossil record. In a new paper, published today in Science Advances, an international team has identified a major extinction of life 233 million years ago that triggered the dinosaur takeover of the world. The crisis has been called the Carnian Pluvial Episode.

The team of 17 researchers, led by Jacopo Dal Corso of the China University of Geosciences at Wuhan and Mike Benton of the University of Bristol's School of Earth Sciences, reviewed all the geological and palaeontological evidence and determined what had happened.

The cause was most likely massive volcanic eruptions in the Wrangellia Province of western Canada, where huge volumes of volcanic basalt was poured out and forms much of the western coast of North America.

"The eruptions peaked in the Carnian," says Jacopo Dal Corso. "I was studying the geochemical signature of the eruptions a few years ago and identified some massive effects on the atmosphere worldwide. The eruptions were so huge, they pumped vast amounts of greenhouse gases like carbon dioxide, and there were spikes of global warming". The warming was associated with increased rainfall, and this had been detected back in the 1980s by geologists Mike Simms and Alastair Ruffell as a humid episode lasting about 1 million years in all. The climate change caused major biodiversity loss in the ocean and on land, but just after the extinction event new groups took over, forming more modern-like ecosystems. The shifts in climate encouraged growth of plant life, and the expansion of modern conifer forests.

"The new floras probably provided slim pickings for the surviving herbivorous reptiles," said Professor Mike Benton. "I had noted a floral switch and ecological catastrophe among the herbivores back in 1983 when I completed my PhD. We now know that dinosaurs originated some 20 million years before this event, but they remained quite rare and unimportant until the Carnian Pluvial Episode hit. It was the sudden arid conditions after the humid episode that gave dinosaurs their chance."

It wasn't just dinosaurs, but also many modern groups of plants and animals also appeared at this time, including some of the first turtles, crocodiles, lizards, and the first mammals.

The Carnian Pluvial Episode also had an impact on ocean life. It marks the start of modern-style coral reefs, as well as many of the modern groups of plankton, suggesting profound changes in the ocean chemistry and carbonate cycle.

"So far, palaeontologists had identified five "big" mass extinctions in the past 500 million yeas of the history of life," says Jacopo Dal Corso. "Each of these had a profound effect on the evolution of the Earth and of life. We have identified another great extinction event, and it evidently had a major role in helping to reset life on land and in the oceans, marking the origins of modern ecosystems."

Paper: 'Extinction and dawn of the modern world in the Carnian (Late Triassic)' by J. Dal Corso and 16 others in Science Advances 6, eaba0099.
-end-


University of Bristol

Related Dinosaurs Articles:

Some dinosaurs could fly before they were birds
New research using the most comprehensive study of feathered dinosaurs and early birds has revised the evolutionary relationships of dinosaurs at the origin of birds.
Tracking Australia's gigantic carnivorous dinosaurs
North America had the T. rex, South America had the Giganotosaurus and Africa the Spinosaurus - now evidence shows Australia had gigantic predatory dinosaurs.
Ancient crocodiles walked on two legs like dinosaurs
An international research team has been stunned to discover that some species of ancient crocodiles walked on their two hind legs like dinosaurs and measured over three metres in length.
Finding a genus home for Alaska's dinosaurs
A re-analysis of dinosaur skulls from northern Alaska suggests they belong to a genus Edmontosaurus, and not to the genus recently proposed by scientists in 2015.
Can we really tell male and female dinosaurs apart?
Scientists worldwide have long debated our ability to identify male and female dinosaurs.
In death of dinosaurs, it was all about the asteroid -- not volcanoes
Volcanic activity did not play a direct role in the mass extinction event that killed the dinosaurs, according to an international, Yale-led team of researchers.
Discriminating diets of meat-eating dinosaurs
A big problem with dinosaurs is that there seem to be too many meat-eaters.
Jurassic dinosaurs trotted between Africa and Europe
Dinosaur footprints found in several European countries, very similar to others in Morocco, suggest that they could have been dispersed between the two continents by land masses separated by a shallow sea more than 145 million years ago.
In the shadow of the dinosaurs
Research published this Wednesday in Scientific Reports describes Clevosaurus hadroprodon, a new reptile species from Rio Grande do Sul state in southern Brazil.
When the dinosaurs died, lichens thrived
When the asteroid hit, dinosaurs weren't the only ones that suffered.
More Dinosaurs News and Dinosaurs Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Listen Again: The Power Of Spaces
How do spaces shape the human experience? In what ways do our rooms, homes, and buildings give us meaning and purpose? This hour, TED speakers explore the power of the spaces we make and inhabit. Guests include architect Michael Murphy, musician David Byrne, artist Es Devlin, and architect Siamak Hariri.
Now Playing: Science for the People

#576 Science Communication in Creative Places
When you think of science communication, you might think of TED talks or museum talks or video talks, or... people giving lectures. It's a lot of people talking. But there's more to sci comm than that. This week host Bethany Brookshire talks to three people who have looked at science communication in places you might not expect it. We'll speak with Mauna Dasari, a graduate student at Notre Dame, about making mammals into a March Madness match. We'll talk with Sarah Garner, director of the Pathologists Assistant Program at Tulane University School of Medicine, who takes pathology instruction out of...
Now Playing: Radiolab

What If?
There's plenty of speculation about what Donald Trump might do in the wake of the election. Would he dispute the results if he loses? Would he simply refuse to leave office, or even try to use the military to maintain control? Last summer, Rosa Brooks got together a team of experts and political operatives from both sides of the aisle to ask a slightly different question. Rather than arguing about whether he'd do those things, they dug into what exactly would happen if he did. Part war game part choose your own adventure, Rosa's Transition Integrity Project doesn't give us any predictions, and it isn't a referendum on Trump. Instead, it's a deeply illuminating stress test on our laws, our institutions, and on the commitment to democracy written into the constitution. This episode was reported by Bethel Habte, with help from Tracie Hunte, and produced by Bethel Habte. Jeremy Bloom provided original music. Support Radiolab by becoming a member today at Radiolab.org/donate.     You can read The Transition Integrity Project's report here.