Dinosaur-killing asteroid also triggered a global warming that lasted 100,000 years


Dinosaur-killing asteroid also triggered a global warming that lasted 100,000 years

Researchers has revealed that dinosaurs were not the only casualty of the catastrophic asteroid event 66 million years ago.

"The avian family tree tells you about the hierarchical relationships among bird species", Berv explained.

Field says that the study came to be little by little, and that it took some time to gather all the information.

It began with analysis of how bird ecology had changed over evolutionary history. The aftereffects of the Chicxulub impact remain debated, with some scientists advocating that soot within the atmosphere blocked out the sun sufficiently to drive global cooling; others suggest that carbon released from the Earth's crust into the atmosphere upon the asteroid's impact, as well as carbon from wildfires, had a warming effect.

"Today, birds are the most diverse and globally widespread group of terrestrial vertebrate animals - there are almost 11,000 living species", Field said in a statement.

Tyler Lyson, a paleontologist at the Denver Museum of Nature and Science, helped write that study.

But it's also incredibly important to study what happened during the fifth mass extinction because many scientists believe we're entering the sixth mass extinction.

The scientists found that there was a spike in the amount of fern spores after the asteroid hit. Ferns are normally amongst the quickest plants to return after natural catastrophes. "To date, there's really been no good empirical estimates on what temperature is doing following the impact, in terms of hundreds of thousands of years", says Page Quinton, a geologist at the State University of NY at Potsdam. None of these birds survived, which the authors surmise was because their habitat had entirely vanished.

Most of the large terrestrial animals in Mesozoic died immediately after the impact, "but marine animals and those that could hide in underground lakes or that could remain underwater for longer periods could have survived". The trees, then, must have been lost.

MacLeod's team now want to look at fossil samples from other parts of the world and check for similar patterns. "We know that the diversity of bird communities is impacted by the availability of forests - when forests are cut down in favor of, for example, palm oil monoculture, bird diversity is slashed".

"This is a tantalizing new hypothesis that provides a suitable explanation for the extinction of arboreal groups of archaic birds at the end of the Cretaceous", he says. "It took a lot longer for some bird species to evolve the shorter legs and grasping feet needed to perch and nest in trees". "The same can not be said of all explanations for why dinosaurs go extinct". Forest fires broke out all over the world. Field and his colleagues also hope to fill in gaps in the fossil record for birds, which is sparse in the first few million years following the impact.

He says he's excited to share this information with visitors because it answers questions about the past and sheds new light on the future.

Their fossils expose that the ground-dwelling birds had long, strong legs, like those of a kiwi or an emu, absolutely nothing like the fragile legs of setting down birds.



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