Posted on 10/24/2019 8:04:31 PM PDT by BenLurkin
More than three-quarters of species on Earth died out. But life came back, and land mammals began to expand from being small creatures into the wide array of forms we see today—including us.
So the new find taps into "the origin of the modern world," said Tyler Lyson, an author of a paper reporting the fossil finds Thursday in the journal Science. The fossils were recovered from an area of steep bluffs covering about 10 square miles (17 square kilometers) near Colorado Springs, starting three years ago.
Scientists have previously found little evidence about what happened in the aftermath of the meteorite crash, especially on land, said Jin Meng of the American Museum of Natural History in New York. The new work, he said in an email, appears to provide "the best record on Earth to date."
The study reports on hundreds of mammal fossils representing 16 species and more than 6,000 plant fossils. Researchers also analyzed thousands of pollen grains to see what plants were alive at various times. Analysis of leaves indicated several warming periods during the period.
(Excerpt) Read more at phys.org ...
Its source Science article says the legume family appeared abruptly and dramatically in the Americas after the Impact. That supports the concept that opening up of the plant ecosphere allowed new plant food sources for land aminals which further speeded up animal diversification after the Impact.
“Analysis of leaves indicated several warming periods during the period.”
Gee...YA THINK???
It’s interesting that they don’t state WHY the Earth was in a “warming period” or “warming periods”...
In fact, of the 10 “related articles” I scanned, NONE of them used the words “cold” or “freeze” at ALL.
Why do they avoid discussing the deep FREEZE which is well established to have occurred after the Chicxulub impact?
The million dollar question is how long the planet was in a deep freeze; they don’t know, they just “theorize” since none of their computer models can predict modern climate...let alone recreate historical or ancient climate.
From one of the ‘related articles’:
“The K-Pg extinction wiped out around 60 percent of the marine species around Antarctica, and 75 percent of species around the world. Victims of the extinction included the dinosaurs and the ammonites. It was caused by the impact of a 10 km asteroid on the Yucatán Peninsula, Mexico, and occurred during a time period when the Earth was experiencing environmental instability from a major volcanic episode. Rapid climate change, global darkness, and the collapse of food chains affected life all over the globe.”
“Global darkness” was the only reference I found.
Why? (rhetorical)
Consider the lowly(and disgusting) cockroach. That thing has been crawling around this planet for some 450 million years. A big hunk of rock from space? Meh!
I think what they mean is 10 miles square. That would be closer to 17 km square.
None of your business. Let them have a little privacy and dignity. :^)
That would work.
Let alone the fact that currently it happens every 124k, and it happened at closer intervals the further back you go in the timeline.
Or the source of my having been riled: The fact that we’re in a ‘warming period’ now in spite of our existence...
When in fact we have actually been in a cooling period for the last 8k...
I would guess a matter of days.
Chicxulub was a shallow water strike and the surrounding sea formed a wall around the white hot crater as it attempted to flood in. It was like a 120 mile wide rocket nozzle jetting vaporized seawater and any entrained atmosphere into space. As the crater was quenched, the force of the boiling reduced, and the remaining flood of sea water and air steam-cleaned half the planet.
It was a bad day.
Add to that atmospheric pressure drop an injection of sulfur an oxides of nitrogen into the now thinned atmosphere, and smoke for continent wide fires caused by red hot ejecta falling back to earth.
For you or me, it would be like moving from sea level to Leadville CO, nearly two miles above sea level. Add gale or hurricane force winds blowing towards the crater and ultimately space, everything around you is burning, choking smoke, sulfuric vapor, and soon murky darkness as the flames die down. We’d gasp for breath at every step, have burns on most of our bodies, anything we could eat would be ash, everywhere we step is scorching hot.
A very bad day.
On land nothing larger than a house cat survived. I suspect all the surviving animals were burrow dwellers or buried egg nesters, animals already used to enduring lower oxygen content than their larger peers. The thinned atmosphere was a final insult to the bigger surface dwellers.
Very good analysis of the cause and effect results.
Thank you.
I am a firm believer that we try too hard to blame just one variable with these things when it could actually be many different factors and variables that in total combination caused the end effect. I try not too, but I sometimes get pulled back into the box.
I had never put much thought into this event to realize all the different factor variables that may have come together in the total as a combination, such as species that were already adapted to low oxygen environments.
You just did that very well, thank you, it pulled me back out of the box and raised a lot of curiosities for me to look into further. :)
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