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

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

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Discovery of the oldest plant fossils on the African continent
https://phys.org/news/2021-06-discovery ... inent.html
by Cyril Prestianni, University de Liege
The analysis of very old plant fossils discovered in South Africa and dating from the Lower Devonian period documents the transition from barren continents to the green planet we know today. Cyrille Prestianni, a palaeobotanist at the EDDy Lab at the University of Liège (Belgium), participated in this study, the results of which have just been published in the journal Scientific Reports.

The greening of continents—or terrestrialisation—is undoubtedly one of the most important processes that our planet has undergone. For most of the Earth's history, the continents were devoid of macroscopic life, but from the Ordovician period (480 million years ago) green algae gradually adapted to life outside the aquatic environment. The conquest of land by plants was a very long process during which plants gradually acquired the ability to stand upright, breathe in the air or disperse their spores. Plant fossils that document these key transitions are very rare. In 2015, during the expansion of the Mpofu Dam (South Africa), researchers discovered numerous plant fossils in geological strata dated to the Lower Devonian (420—410 million years ago), making this a truly exceptional discovery.
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caltrek
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Re: Natural History (13.8 billion years BC – 3.3 million BC)

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A volcanic eruption 39 million years ago buried a forest in Peru – now the petrified trees are revealing South America’s primeval history

https://theconversation.com/a-volcanic- ... 160160/url

Introduction:
In the hills outside the small village of Sexi, Peru, a fossil forest holds secrets about South America’s past millions of years ago.

When we first visited these petrified trees more than 20 years ago, not much was known about their age or how they came to be preserved. We started by dating the rocks and studying the volcanic processes that preserved the fossils. From there, we began to piece together the story of the forest, starting from the day 39 million years ago when a volcano erupted in northern Peru.

Ash rained down on the forest that day, stripping leaves from the trees. Then flows of ashy material moved through, breaking off the trees and carrying them like logs in a river to the area where they were buried and preserved. Millions of years later, after the modern-day Andes rose and carried the fossils with them, the rocks were exposed to the forces of erosion, and the fossil woods and leaves again saw the light of day.

This petrified forest, El Bosque Perificado Piedra Chamana, is the first fossil forest from the South American tropics to be studied in detail. It is helping paleontologists like us to understand the history of the megadiverse forests of the New World tropics and the past climates and environments of South America.
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Re: Natural History (13.8 billion years BC – 3.3 million BC)

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Giant rhino that once roamed China may be ‘largest land mammal’ that ever lived
Friday 18 Jun 2021

Image

A giant rhino dug up in China could be ‘the largest land mammal’ that ever lived, say scientists.

The colossal creature was more than 26 feet long, over 16 foot tall and weighed 24 tonnes.

It was four times the size of an African elephant – the biggest animal that walks the Earth today.

The hornless herbivore roamed Asia 26.5 million years ago – browsing the forests for leaves, soft plants and shrubs.

It resembled an overgrown tapir – and has been named Paraceratherium linxiaense. The bizarre animal had a slender skull, short trunk and an unusually long and muscular neck.
https://metro.co.uk/2021/06/18/giant-rh ... -14792600/
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Re: Natural History (13.8 billion years BC – 3.3 million BC)

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The 27.5-million-year cycle of geological activity
https://phys.org/news/2021-06-million-y ... gical.html
by New York University

Geologic activity on Earth appears to follow a 27.5-million-year cycle, giving the planet a 'pulse,' according to a new study published in the journal Geoscience Frontiers.

"Many geologists believe that geological events are random over time. But our study provides statistical evidence for a common cycle, suggesting that these geologic events are correlated and not random," said Michael Rampino, a geologist and professor in New York University's Department of Biology, as well as the study's lead author.

Over the past five decades, researchers have proposed cycles of major geological events—including volcanic activity and mass extinctions on land and sea—ranging from roughly 26 to 36 million years. But early work on these correlations in the geological record was hampered by limitations in the age-dating of geologic events, which prevented scientists from conducting quantitative investigations.
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Re: Natural History (13.8 billion years BC – 3.3 million BC)

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Geochemical study confirms cause of end-Permian mass extinction event

by Heather Tate, Northern Arizona University
https://phys.org/news/2021-06-geochemic ... event.html
The most severe mass extinction event in the past 540 million years eliminated more than 90 percent of Earth's marine species and 75 percent of terrestrial species. Although scientists had previously hypothesized that the end-Permian mass extinction, which took place 251 million years ago, was triggered by voluminous volcanic eruptions in a region of what is now Siberia, they were not able to explain the mechanism by which the eruptions resulted in the extinction of so many different species, both in the oceans and on land.

Associate professor Laura Wasylenki of Northern Arizona University's School of Earth and Sustainability and Department of Chemistry and Biochemistry is co-author on a new paper in Nature Communications entitled, "Nickel isotopes link Siberian Traps aerosol particles to the end-Permian mass extinction," in collaboration with Chinese, Canadian and Swiss scientists. The paper presents the results of nickel isotope analyses performed in Wasylenki's lab on Late Permian sedimentary rocks collected in Arctic Canada. The samples have the lightest nickel isotope ratios ever measured in sedimentary rocks, and the only plausible explanation is that the nickel was sourced from the volcanic terrain, very likely carried by aerosol particles and deposited in the ocean, where it dramatically changed the chemistry of seawater and severely disrupted the marine ecosystem.
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Re: Natural History (13.8 billion years BC – 3.3 million BC)

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Earth has a ‘pulse’ every 27.5 million years that brings eruptions and mass extinctions
Mon, 21 June 2021

Disastrous events including volcanic eruptions and mass extinctions seem to occur regularly – dictated by a “pulse” that beats every 27.5 million years, a new study found.

Researchers used improved radio-isotope dating technology to precisely pinpoint disasters including sea level rises and volcanic outbursts.

They found that such events are “not random” and appear to be linked to a recurring cycle of major geological events.

The last cycle was 7 million years ago, meaning it should be another 20 million years until another round of such events.

Michael Rampino, a geologist and professor in New York University's Department of Biology, said, "Many geologists believe that geological events are random over time. But our study provides statistical evidence for a common cycle, suggesting that these geologic events are correlated and not random.”
https://uk.news.yahoo.com/pulse-extinct ... 48847.html
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weatheriscool
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Re: Natural History (13.8 billion years BC – 3.3 million BC)

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Tiny ancient bird from China shares skull features with Tyrannosaurus rex
https://phys.org/news/2021-06-tiny-anci ... skull.html
by Chinese Academy of Sciences

Researchers from the Institute of Vertebrate Paleontology and Paleoanthropology (IVPP) of the Chinese Academy of Sciences have discovered a 120-million-year-old partial fossil skeleton of a tiny extinct bird that fits in the palm of the hand and preserves a unique skull with a mix of dinosaurian and bird features.

The two-centimeter-long (0.75 inch) skull of the fossil shares many structural and functional features with the gigantic Tyrannosaurus rex, indicating that early birds kept many features of their dinosaurian ancestors and their skulls functioned much like those of dinosaurs rather than living birds.

Their findings were published in Nature Communications on June 23.

The bird was deposited 120 million years ago in a shallow lake in what is today Liaoning Province in northeastern China.
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Re: Natural History (13.8 billion years BC – 3.3 million BC)

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weatheriscool
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Dinosaurs were in decline before the end, according to new study

https://phys.org/news/2021-06-dinosaurs-decline.html

by University of Bristol

The death of the dinosaurs 66 million years ago was caused by the impact of a huge asteroid on the Earth. However, palaeontologists have continued to debate whether they were already in decline or not before the impact.

In a new study, published today in the journal Nature Communications, an international team of scientists, which includes the University of Bristol, show that they were already in decline for as much as ten million years before the final death blow.

Lead author, Fabien Condamine, a CNRS researcher from the Institut des Sciences de l'Evolution de Montpellier (France), said: "We looked at the six most abundant dinosaur families through the whole of the Cretaceous, spanning from 150 to 66 million years ago, and found that they were all evolving and expanding and clearly being successful.

"Then, 76 million years ago, they show a sudden downturn. Their rates of extinction rose and in some cases the rate of origin of new species dropped off."
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Re: Natural History (13.8 billion years BC – 3.3 million BC)

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'Icelandia': Is Iceland the tip of a vast, sunken continent?
June 30, 2021

Academics believe they have identified a remarkable geological secret: A sunken continent hidden under Iceland and the surrounding ocean,which they have dubbed "Icelandia."

An international team of geologists, led by Gillian Foulger, Emeritus Professor of Geophysics in the Department of Earth Sciences at Durham University (UK), believe the sunken continent could stretch from Greenland all the way to Europe.

It is believed to cover an area of ~600,000 km2 but when adjoining areas west of Britain are included in a "Greater Icelandia," the entire area could be ~1,000,000 km2 in size.

If proven, it means that the giant supercontinent of Pangaea, which is thought to have broken up over 50 million years ago, has in fact not fully broken up.

This new theory challenges long-held scientific ideas around the extent of oceanic and continental crust in the North Atlantic region, and how volcanic islands, like Iceland, formed.
https://phys.org/news/2021-06-icelandia ... inent.html
"We all have our time machines, don't we. Those that take us back are memories...And those that carry us forward, are dreams."

-H.G Wells.
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