Natural History (13.8 billion years BC – 3.3 million BC)

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Time_Traveller
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Re: Natural History (13.8 billion years BC – 3.3 million BC)

Post by Time_Traveller »

City-sized asteroids smacked ancient Earth 10 times more often than thought
2 days ago

Image

Asteroids the size of cities, like the one that wiped out the dinosaurs, slammed into the ancient Earth way more often than previously thought, a new study has found.

Approximately every 15 million years, our evolving planet would get a hit by a piece of rock about the size of a city, or even a bigger province, scientists with the new study said in a statement. The research was presented at the Goldschmidt geochemistry conference last week.

This violent period, which took place between 2.5 and 3.5 billion years ago, saw the planet in upheaval on a regular basis, with the chemistry near its surface undergoing dramatic changes that can be traced in the rocks in the ground even today, the researchers said.

In the study, Simone Marchi a principal scientist with the Southwest Research Institute in Boulder, Colorado and colleagues looked at the presence of the so-called spherules, small bubbles of vaporized rock that were thrown up to space by every asteroid impact, but then solidified and fell back to Earth, forming a thin layer that geologists see in the bedrock today.
https://www.space.com/ancient-earth-hit ... oids-often
“People assume that time is a strict progression of cause to effect, but *actually* from a non-linear, non-subjective viewpoint - it's more like a big ball of wibbly wobbly... time-y wimey... stuff.” - Steven Moffat
weatheriscool
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Re: Natural History (13.8 billion years BC – 3.3 million BC)

Post by weatheriscool »

Megaripples may be evidence of giant tsunami resulting from Chicxulub impact
https://phys.org/news/2021-07-megarippl ... lting.html
by Bob Yirka , Phys.org
A pair of geophysicists from the University of Louisiana at Lafayette working with two independent researchers has found what they believe might be evidence of a massive tsunami created by the Chicxulub asteroid impact. In their paper published in the journal Earth and Planetary Science Letters, the group describes their study of seismic data for a site in Louisiana and what they found.

Most scientists agree that approximately 66 million years ago, a large asteroid struck the Earth near what is now the Yucatan peninsula. It is also believed that the impact was so violent that it covered the globe with dust for several years, leading to the demise of the dinosaurs. Some in the field have suggested that the collision also resulted in the creation of a massive tsunami. In this new effort, the researchers reasoned that this tsunami would have made its way across what is now the Gulf of Mexico to the shores of North America. They suggest such a massive collision would have created a wave up to a mile high as it made its way onshore. If so, they further reasoned, there should be evidence of unique geographical formations—the kind that are known to be created by modern tsunamis.

To search for evidence of possible formations, the researchers studied the terrain at a place where the tsunami would have struck and then chose what they believed to be a good place to look more closely: inland Louisiana. To find the evidence they were looking for, the team obtained seismic data from a petroleum firm that allowed them to look at soil at depths up to 1,500 meters below the surface. They found evidence of what they describe as megaripples—huge fossilized ripples that would have been created by a massive influx of water, which then receded. The researchers then studied the ripples to learn more about the direction of the flow of water that had created them, and found they pointed straight to the Chicxulub asteroid impact site. The researchers suggest their find adds yet another piece to the emerging picture of the Chicxulub asteroid impact event.
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Re: Natural History (13.8 billion years BC – 3.3 million BC)

Post by Time_Traveller »

'Jurassic Pompeii' yields thousands of 'squiggly wiggly' fossils
14 hours ago

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"If they could squeal, I'm sure they would have done."

Palaeontologist Tim Ewin is standing in a quarry, recalling the calamity that's written in the rocks under his mud-caked boots.

"They tried to protect themselves, adopting the stress position of pulling their arms in," he continues. "But it was all in vain; you can see where their arms got snagged open, right up to the crown. They were pushed into the sediment and buried alive."

There's a little smile creeping across Tim's face, and he's got reason to be happy.

The misfortune that struck this place 167 million years ago has delivered to him an extraordinary collection of fossil animals in what is unquestionably one of the most important Jurassic dig sites ever discovered in the UK.
https://www.bbc.co.uk/news/science-environment-57853537
“People assume that time is a strict progression of cause to effect, but *actually* from a non-linear, non-subjective viewpoint - it's more like a big ball of wibbly wobbly... time-y wimey... stuff.” - Steven Moffat
weatheriscool
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Re: Natural History (13.8 billion years BC – 3.3 million BC)

Post by weatheriscool »

Newly-hatched pterosaurs may have been able to fly
https://phys.org/news/2021-07-newly-hat ... saurs.html
by University of Portsmouth
Newly-hatched pterosaurs may have been able to fly but their flying abilities may have been different from adult pterosaurs, according to a new study.

Pterosaurs were a group of flying reptiles that lived during the Triassic, Jurassic and Cretaceous Periods (228 to 66 million years ago). Due to the rarity of fossilized pterosaur eggs and embryos, and difficulties distinguishing between hatchlings and small adults, it has been unclear whether newly-hatched pterosaurs were able to fly.

Researchers from the Universities of Portsmouth and Bristol, along with paleontologist Darren Naish, found that hatchling humerus bones were stronger than those of many adult pterosaurs, indicating that they would have been strong enough for flight.
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Re: Natural History (13.8 billion years BC – 3.3 million BC)

Post by weatheriscool »

Icy waters of 'Snowball Earth' may have spurred early organisms to grow bigger
https://phys.org/news/2021-07-icy-snowb ... early.html
by Daniel Strain, University of Colorado at Boulder

A new study from CU Boulder finds that hundreds of millions of years ago, small single-celled organisms may have evolved into larger multicellular life forms to better propel themselves through icy waters.

The research was led by paleobiologist Carl Simpson and appears today in the journal The American Naturalist. It hones in on a question that's central to the history of the planet: How did life on Earth, which started off teeny-tiny, get so big?

"Once organisms get big, they have a clear ecological advantage because the physics around how they capture food become totally different," said Simpson, assistant professor in the Department of Geological Sciences and the CU Museum of Natural History. "But the hard part for researchers has been explaining how they got big in the first place."

In his latest study, Simpson draws on a series of mathematical equations to argue that this all-important shift may have come down to hydrodynamics—or the pursuit of a more efficient backstroke.
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Re: Natural History (13.8 billion years BC – 3.3 million BC)

Post by caltrek »

Mysterious Oxygen Burst Was Tied to Earth's Biggest Mass Extinction, Scientists Say
by David Nield
August 4, 2021

https://www.sciencealert.com/ocean-oxyg ... tion-event

Introduction:
(Science Alert)The Permian-Triassic extinction event that happened some 252 million years ago is the worst extinction event our planet has ever seen. It wiped out around 90 percent of marine species and some 70 percent of vertebrate species on land, and was so severe that it's often called the Great Dying.

There are still lots of unanswered questions about the event, from its overall timescale to its causes, but a new study offers some intriguing extra detail on the calamity: a sudden spike in oxygen levels in the world's oceans at the same time as this widespread extinction was happening.

The researchers behind the study think that the sudden burst of oceanic oxygenation occurred around the start of the Great Dying, and was spread across tens of thousands of years, before oxygen levels then began to steadily drop again.

"For the geological record, that's practically instantaneous," says Earth scientist Sean Newby from Florida State University (FSU).

"And then you can of course compare that to modern, human-induced climate change, where we're having huge, rapid changes in fractions of the time compared to this mass extinction."
caltrek's comment: If I recall correctly, the notion that an increase in oxygen levels can be tied to a mass extinction event has been discussed by scientists for decades. James Lovelock is an example of one such scientist.
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Re: Natural History (13.8 billion years BC – 3.3 million BC)

Post by caltrek »

Scientists Discover Fossils of ‘Real Life Dragon’ in Australia
by Jon Parton
August 9, 2021

https://www.courthousenews.com/scientis ... australia/

Introduction:
(Courthouse News) — Scientists discovered the fossils of the largest flying reptile in Australia, a massive pterosaur with a 22-foot wingspan that made its home in the outback of Queensland.

“It’s the closest thing we have to a real life dragon,” said Tim Richards of the University of Queensland.

Richards and a team of researchers made the discovery while examining a fossil of the pterosaur’s jaw that was found in Northwest Queensland.

“The new pterosaur, which we named Thapunngaka shawi, would have been a fearsome beast, with a spear-like mouth and a wingspan around seven meters [22 feet],” Richards said in a statement. “It was essentially just a skull with a long neck, bolted on a pair of long wings.

“This thing would have been quite savage. It would have cast a great shadow over some quivering little dinosaur that wouldn’t have heard it until it was too late.”
Image
Artist’s impression of the fearsome Thapunngaka shawi.
Credit: Tim Richards
weatheriscool
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Re: Natural History (13.8 billion years BC – 3.3 million BC)

Post by weatheriscool »

Shark diversity unaffected when the dinosaurs were wiped out
https://phys.org/news/2021-08-shark-div ... saurs.html
by Public Library of Science

A global catastrophe 66 million years ago led to the extinction of all non-avian dinosaurs, and large marine reptiles like mosasaurs and plesiosaurs. But what happened to the sharks? According to a study of sharks' teeth publishing August 10th in the open-access journal PLOS Biology by Mohamad Bazzi of Uppsala University and colleagues, shark-tooth diversity remained relatively constant across the mass extinction event at the end of the Cretaceous.

The researchers analyzed the morphology of 1239 fossil shark teeth, including species in eight existing orders and one now-extinct order. The teeth span a 27-million-year period from the late Cretaceous 83.6 million years ago to the early Paleogene 56 million years ago, across the so-called K-Pg boundary that brought the age of the dinosaurs to an end.

The scientists found that shark dental diversity was already declining prior to the K-Pg boundary, but remained relatively constant during the mass-extinction event itself. Some groups of apex predators, particularly those with triangular blade-like teeth, did suffer selective extinctions during the period studied, which may have been linked to the extinction of their prey species.
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Yuli Ban
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Re: Natural History (13.8 billion years BC – 3.3 million BC)

Post by Yuli Ban »

weatheriscool wrote: Tue Aug 10, 2021 6:06 pm Shark diversity unaffected when the dinosaurs were wiped out
https://phys.org/news/2021-08-shark-div ... saurs.html
by Public Library of Science

A global catastrophe 66 million years ago led to the extinction of all non-avian dinosaurs, and large marine reptiles like mosasaurs and plesiosaurs. But what happened to the sharks? According to a study of sharks' teeth publishing August 10th in the open-access journal PLOS Biology by Mohamad Bazzi of Uppsala University and colleagues, shark-tooth diversity remained relatively constant across the mass extinction event at the end of the Cretaceous.

The researchers analyzed the morphology of 1239 fossil shark teeth, including species in eight existing orders and one now-extinct order. The teeth span a 27-million-year period from the late Cretaceous 83.6 million years ago to the early Paleogene 56 million years ago, across the so-called K-Pg boundary that brought the age of the dinosaurs to an end.

The scientists found that shark dental diversity was already declining prior to the K-Pg boundary, but remained relatively constant during the mass-extinction event itself. Some groups of apex predators, particularly those with triangular blade-like teeth, did suffer selective extinctions during the period studied, which may have been linked to the extinction of their prey species.
It something that tends to take me off guard every time I hear it: just how ancient sharks are. They're among the first large scale life forms on Earth!
And remember my friend, future events such as these will affect you in the future
caltrek
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Re: Natural History (13.8 billion years BC – 3.3 million BC)

Post by caltrek »

Ancient Australian Volcanic Rock May Hold the Secret to Life on Earth
by Tara Yarlagadda
August 9, 2021

https://www.inverse.com/science/volcano ... -of-oxygen

Extract:
(Inverse) THE PILBARA REGION OF WESTERN AUSTRALIA offers stunningly strange vistas of volcanic rock and granite domes that feel reminiscent of an ancient world — and for a good reason.

These arid mineral-rich lands support Australia’s mining and crude oil industries, but they also reveal remarkable geological secrets about ancient Earth long before humans roamed the planet.

According to new research, the Pilbara Craton — one of the few crusts remaining on Earth from the Archaean era 2.7 to 3.6 billion years ago — could help us understand the emergence of Earth’s most essential ingredient for life: oxygen.

WHY IT MATTERS — Most research on oxygen during the ancient Archaean era has focused on the Great Oxygenation Event, which occurred roughly 2.4 billion years ago. This event brought oxygen to early Earth’s oceans and atmosphere, creating the conditions for life to eventually flourish.

But previous research has shown that a brief, so-called “whiff” of oxygen emerged on Earth roughly 2.5 billion years ago, which meant that there was oxygen on Earth for 500 million years before the Great Oxygenation Event.
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