New simulations add to growing evidence that an asteroid strike, rather than the Deccan Traps eruptions, caused the end-Cretaceous extinction.
For decades, scientists have gone back and forth about whether massive volcanic eruptions or an asteroid impact — or maybe both — caused a mass extinction that saw the demise of all nonbird dinosaurs about 66 million years ago.
Now, geologic evidence and data on dinosaur habitats, combined with climate and ecological simulations, suggest it wasn’t the volcanism. Instead, a decades-long cold winter triggered by the giant impact wiped out dinosaur habitats and made it impossible for the creatures to survive, researchers report June 29 in Proceedings of the National Academy of Sciences.
In a plot twist, volcanism at the Deccan Traps, in what is now India, may have actually ameliorated the negative effects of the long winter, warming the planet quicker than would have occurred otherwise and allowing mammals room to thrive, the researchers say.
“It’s a complete change in the narrative of Deccan volcanism … [which] may well have been the benevolent hero of the time,” says Alexander Farnsworth, a paleoclimatologist at the University of Bristol in England.
Belgian and Dutch palaeontologists have discovered that the marine life in our regions recovered exceptionally quickly after the meteorite impact that heralded the end of the dinosaurs.
The impact of a meteorite of up to 10 kilometres in diameter on the Mexican peninsula of Yucatan 66 million years ago caused worldwide environmental disasters with tsunamis, a nuclear winter, acid rain and sudden climate changes. The result: one of the biggest biodiversity crises ever. Three quarters of the animal kingdom and half of all plant species were wiped off the map.
However, the consequences of the meteorite impact were not equally dramatic everywhere. A new study by Belgian and Dutch palaeontologists from KU Leuven, the Royal Belgian Institute of Natural Sciences and the Maastricht Natural History Museum shows that life in the subtropical sea that covered Limburg survived the environmental disasters very well.
The former Curfs-Ankerpoort limestone quarry, 5 kilometres east of Maastricht, is one of the few places in the world where one can study the direct effects of the meteorite impact on the marine fauna in detail. The team collected some 1,400 fossils of gastropods and bivalves in limestone layers that date from just before and just after the meteorite impact. 'We found that the diversity of the gastropods from the two periods is very similar, as if these animals had hardly suffered from the environmental disasters', says Johan Vellekoop of the KU Leuven. The Limburg marine fauna was probably already able to survive with smaller supplies of food during the Cretaceous. When the meteorite set in motion a chain reaction of environmental disasters, a large part of the local fauna survived this difficult period, after which the ecosystem here recovered relatively quickly,' says Vellekoop.
The new research shows that the local consequences of global environmental disasters depend very much on the conditions in place prior to the disaster. Life in the Limburg Cretaceous Sea proved exceptionally resilient', concludes Vellekoop.
The study was published in the journal Palaeontology.
[NEWS] Five sci-tech links: dinosaurs, phages, algae, space development, interstellar travel
[NEWS] Five sci-tech links: dinosaurs, phages, algae, space development, interstellar travel
MacLean’s notes the controversy surrounding claims of a remarkable find of fossils dating from the very moment, nearly, of the Chixculub impact 66 million years ago.
Wired looks at how genetically manipulated phages can be used to treat infectious diseases untreatable by antibiotics.
Universe Today notes the usefulness of algae in life-support systems for long-duration crewed missions.
[NEWS] Five sci-tech links: Chixculub archive, male pill, Garfield phones, Nova Scotia, ETI wars
[NEWS] Five sci-tech links: Chixculub archive, male pill, Garfield phones, Nova Scotia, ETI wars
Journalist Douglas Preston U>writes in The New Yorker about a potentially amazing site in North Dakota, a rich fossil bed that may well have been formed in the first hour after the Chixculub asteroid impact that ended the Cretaceous.
Arielle Pardes writes at WIRED about how a potential lack of demand among men might hinder the sale of male contraceptives.
