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

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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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Early Earth was Pummeled 10x More Than Previously Estimated
by Andy Tomaswick
October 28, 2021

https://www.universetoday.com/153118/ea ... ore-153118

Introduction:
(Universe Today) It’s no secret that Earth was bombarded with plenty of meteors for billions of years during the solar system’s early formation. Estimates vary on how much material impacted the planet, but it had a considerable effect on the planet’s atmosphere and the evolution of life. Now, a new study from a team led by researchers at the Southwest Research Institute puts the number at almost ten times the number of previously estimated impacts. That much of a difference could dramatically change how geologists and planetary scientists view the early Earth.

Early on, the solar system was much more populated with space rocks. Those space rocks were known to hit Earth, and speculation abounds about what happened when they did so. Earth eventually partially cleaned out its orbital path, culminating in the period called the Late Heavy Bombardment.

While the destructive power of that time period has been well documented, large asteroids continued to impact the Earth consistently for billions of years. When they did so, they formed “impact spherules” of molten rock that were thrown into the air, solidified, and then landed back on the Earth’s surface. They became distinct sand-grain-sized spherical components of the geological layers laid down when their impact happened.

There are multiple spherule layers in the geologic record, showing that impacts large enough to create sky-bound ejecta were common. More have been found recently, leading researchers to examine whether the newfound abundance of these spherule layers was accounted for in simulations of early asteroid bombardment.

It turns out they weren’t – current bombardment models resulted in about ten times fewer spherule layers that have been found in the geological record. Consequently, that implies up to ten times more major asteroid impacts in that time period than models had predicted
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Re: Natural History (13.8 billion years BC – 3.3 million BC)

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The oldest mineralized sponges in the world found in Ciudad Real
https://phys.org/news/2021-11-oldest-mi ... iudad.html
by Universidad Complutense de Madrid

An international and multidisciplinary piece of research involving the participation of Universidad Complutense de Madrid (UCM) concludes with the discovery of the mineralised fossil remains of the oldest sponges in the world—530 million years old—in phosphate deposits in Fontanarejo (Ciudad Real).

These deposits were described for the first time some 50 years ago, but had not been studied in detail until now. Spicules were discovered among the fossil remains—units of silicon that make up the skeleton—of two types of sponges: hexactinillida and demosponges.

"It should be noted that some of the spicules are structured; in other words, connected to others, practically conserving the same position as the original organism", highlights Pablo Suárez, a researcher at the Department of Geodynamics, Stratigraphy and Paleontology at UCM, and one of the authors of the study published in Geological Magazine.

The sponges can have two types of skeleton: mineralised (as in the case of the sponges in Castile-La Mancha), composed of structured spicules or non-mineralised (formed of organic molecules that degrade).
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Re: Natural History (13.8 billion years BC – 3.3 million BC)

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

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^^^We used to have so-called "Dragonflies" that were fairly common to our local area. They were not all that much smaller than a bird, but not as large as the comparison shown above to a human.
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Re: Natural History (13.8 billion years BC – 3.3 million BC)

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

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New dinosaur species from Chile had a unique slashing tail
https://phys.org/news/2021-12-dinosaur- ... shing.html
by Seth Borenstein
Fossils found in Chile are from a strange-looking dog-sized dinosaur species that had a unique slashing tail weapon, scientists reported Wednesday.

Some dinosaurs had spiked tails they could use as stabbing weapons and others had tails with clubs. The new species, described in a study in the journal Nature, has something never seen before on any animal: seven pairs of "blades" laid out sideways like a slicing weapon used by ancient Aztec warriors, said lead author Alex Vargas.

"It's a really unusual weapon," said Vargas, a University of Chile paleontologist. "Books on prehistoric animals for kids need to update and put this weird tail in there. ... It just looks crazy."

The plant-eating critter had a combination of traits from different species that initially sent paleontologists down the wrong path. The back end, including its tail weapon, seemed similar to a stegosaurus, so the researchers named it stegouros elengassen.
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Re: Natural History (13.8 billion years BC – 3.3 million BC)

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

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Study pinpoints timing of Chicxulub asteroid impact
https://phys.org/news/2021-12-chicxulub ... mpact.html
by Florida Atlantic University
A groundbreaking study led by researchers at Florida Atlantic University and an international team of scientists conclusively confirms the time year of the catastrophic Chicxulub asteroid, responsible for the extinction of dinosaurs and 75 percent of life on Earth 66 million years ago. Springtime, the season of new beginnings, ended the 165-million-year reign of dinosaurs and changed the course of evolution on Earth.

Results of the study, published in the journal Scientific Reports, greatly enhances the ability to trace the first stages of damage to life on Earth. FAU's Robert DePalma, senior author and an adjunct professor in the Department of Geosciences, Charles E. Schmidt College of Science, and a doctoral student at the University of Manchester; and Anton Oleinik, Ph.D., second author and an associate professor, FAU's Department of Geosciences, contribute to a major scientific advancement in the ability to understand the massive impact that brought an end to the dinosaurs.

"Time of year plays an important role in many biological functions such as reproduction, feeding strategies, host-parasite interactions, seasonal dormancy, and breeding patterns," said DePalma. "Hence, it is no surprise that the time of year for a global-scale hazard can play a big role in how harshly it impacts life. The seasonal timing of the Chicxulub impact has therefore been a critical question for the story of the end-Cretaceous extinction. Until now, the answer to that question has remained unclear."
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Re: Natural History (13.8 billion years BC – 3.3 million BC)

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Sauropod dinosaurs were restricted to warmer regions of Earth
https://phys.org/news/2021-12-sauropod- ... gions.html
by University College London

Giant, long-necked sauropods, thought to include the largest land animals ever to have existed, preferred to live in warmer, more tropical regions on Earth, suggesting they may have had a different physiology from other dinosaurs, according to a new study led by researchers at UCL and the University of Vigo.

The study, published in the journal Current Biology, investigated the enigma of why sauropod fossils are only found at lower latitudes, while fossils of other main dinosaur types seem ubiquitously present, with many located in the polar regions.

The researchers analyzed the fossil record across the Mesozoic era (the time of the dinosaurs), lasting from around 230 to 66 million years ago, looking at occurrences of fossils of the three main dinosaur types: sauropods, which include the Brontosaurus and the Diplodocus, theropods ("lizard-hipped"), which include velociraptors and Tyrannosaurus rex, and ornithischians ("bird-hipped") such as the Triceratops.
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Re: Natural History (13.8 billion years BC – 3.3 million BC)

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How Did Life Arise?
by Tara Yarlagadda
December 14, 2021

https://www.inverse.com/science/hydrogen-powered-life
(Inverse) WHAT IF... you discovered the origins of all life on Earth, including humans?

It’s a mystery that’s puzzled, frustrated, and fascinated generations of scientists, philosophers, and spiritualists, from Plato to Charles Darwin.

Today’s scientists believe the answer may lie with LUCA — the last universal common ancestor of all life on our planet. This single-cell microorganism, which likely resembled bacteria, is theorized to have lived 4 billion years ago, arising from chemical processes inside Earth’s ancient hydrothermal vents. But scientists have long struggled to understand the biochemical processes — the energy itself — that gave rise to LUCA. Until now.

THE DISCOVERY — In a study published Monday in the journal Frontiers in Microbiology, researchers present what they describe as the fuel driving the metabolic processes that gave rise to LUCA
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