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First ever evidence of a comet striking Earth raining down a shock wave of fire destroying life at ground

First ever evidence of a comet striking Earth raining down a shock wave of fire destroying life at ground | Amazing Science | Scoop.it

The first ever evidence of a comet entering Earth’s atmosphere and exploding, raining down a shock wave of fire which obliterated every life form in its path, has been discovered by a team of South African scientists and international collaborators. The discovery has not only provided the first definitive proof of a comet striking Earth, millions of years ago, but it could also help us to unlock, in the future, the secrets of the formation of our solar system.


“Comets always visit our skies – they’re these dirty snowballs of ice mixed with dust – but never before in history has material from a comet ever been found on Earth,” says Professor David Block of Wits University.

 

The comet entered Earth’s atmosphere above Egypt about 28 million years ago. As it entered the atmosphere, it exploded, heating up the sand beneath it to a temperature of about 2 000 degrees Celsius, and resulting in the formation of a huge amount of yellow silica glass which lies scattered over a 6 000 square kilometer area in the Sahara. A magnificent specimen of the glass, polished by ancient jewellers, is found in Tutankhamun's brooch with its striking yellow-brown scarab.

 

The research, which will be published in Earth and Planetary Science Letters, was conducted by a collaboration of geoscientists, physicists  and astronomers including Block, lead author Professor Jan Kramers of the University of Johannesburg, Dr Marco Andreoli of the South African Nuclear Energy Corporation, and Chris Harris of the University of Cape Town.  

 

At the centre of the attention of this team was a mysterious black pebble found years earlier by an Egyptian geologist in the area of the silica glass. After conducting highly sophisticated chemical analyses on this pebble, the authors came to the inescapable conclusion that it represented the very first known hand specimen of a comet nucleus, rather than simply an unusual type of meteorite.

 

Kramers describes this as a moment of career defining elation. “It’s a typical scientific euphoria when you eliminate all other options and come to the realisation of what it must be,” he said. 

 

The impact of the explosion also produced microscopic diamonds. “Diamonds are produced from carbon bearing material. Normally they form deep in the earth, where the pressure is high, but you can also generate very high pressure with shock. Part of the comet impacted and the shock of the impact produced the diamonds,” says Kramers.

 

The team have named the diamond-bearing pebble “Hypatia” in honour of the first well known female mathematician, astronomer and philosopher, Hypatia of Alexandria. “NASA and ESA (European Space Agency) spend billions of dollars collecting a few micrograms of comet material and bringing it back to Earth, and now we’ve got a radical new approach of studying this material, without spending billions of dollars collecting it,” says Kramers.


The study of Hypatia has grown into an international collaborative research programme, coordinated by Andreoli, which involves a growing number of scientists drawn from a variety of disciplines. Dr Mario di Martino of Turin's Astrophysical Observatory has led several expeditions to the desert glass area.

 

“Comets contain the very secrets to unlocking the formation of our solar system and this discovery gives us an unprecedented opportunity to study comet material first hand,” says Block.

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Ancient oxygen discovery - 700 million years earlier - shakes up history of life on Earth

Ancient oxygen discovery - 700 million years earlier - shakes up history of life on Earth | Amazing Science | Scoop.it

Oxygen appeared in the Earth’s atmosphere up to 700 million years earlier than thought, according to a study led by a B.C. scientist, suggesting that revisions need to be made to current theories about how life evolved on Earth.

Up until now, scientists thought photosynthesis — the ability of living things such as algae and plants to harvest energy from the sun  — first evolved in single-celled organisms about 2.7 billion years ago.

 

Because oxygen is produced during photosynthesis, early photosynthetic organisms are thought to have given rise to the Great Oxygenation Event, also known as the Great Oxidation Event, about 2.3 billion years ago.

The incident was thought to be the first time the atmosphere began accumulating significant amounts of oxygen. That is significant because complex multicellular organisms such as humans require an oxygen-rich atmosphere to survive.

 

The new study led by biogeochemist Sean Crowe has found surprising evidence that as far back as three billion year ago, there were levels of oxygen in the atmosphere too high to have been produced without living organisms.

 

Crowe, an assistant professor in the department of Microbiology and Immunology and the department of Earth, Ocean and Atmospheric Sciences at the University of British Columbia, said people have detected traces of oxygen before in samples older than 2.3 billion years, but the signals were never strong enough to make a conclusion. That is partly because most ancient samples analyzed were marine sediments from the bottom of the ocean, which aren’t in direct contact with the atmosphere, and therefore don’t show very strong oxygen signals at the best of times.


However, researchers in South Africa recently discovered an ancient land-based soil sample called a paleosol that dated back three billion years.

Crowe, in collaboration with colleagues at the University of Southern Denmark, where he was previously a postdoctoral researcher, decided to test the samples for oxygen. The researchers employed a new, more sensitive technique that involves looking for forms of chromium that only occur following reaction with oxygen.

 

Given the age of the samples, Crowe didn’t expect to find any oxygen. So he was surprised when the tests showed “low but appreciable concentrations.”

 “Initially we thought we must have done something wrong or there was something wrong with the samples,” Crowe said.

 

To verify the results, researchers tested marine samples that were about the same age. Using the new chromium technique, they too showed a positive signal for oxygen.

 

“We were very excited,” Crowe said. “Immediately we knew there was oxygen in the atmosphere well before we understood it to be.”

 

The oxygen levels detected in the samples were only a 10,000th of present day levels of 20 per cent of the atmosphere, and a 200th to a 500th of the levels that immediately followed the Great Oxygenation Event.


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Wesley M Leonhardt's comment, October 1, 2013 5:34 PM
The earth's history will always be a mystery, and this article proves it. We have always been taught that the first oxygen on earth came from single celled organisms doing photosynthesis. This new study shows evidence of oxygen existing before these singled celled organisms. Using a soil sample called a paleosol, they discovered proof of oxygen in the soil billions of years ago. Even though oxygen levels were not as high as they are today, it still is a huge scientific discovery that will affect the learning of people in the future.
Wesley M Leonhardt's comment, October 1, 2013 5:39 PM
I feel like this will really affect the scientific thought of the evolution of the earth. The order of evolution will have to be reworked (yay for Adam and Eve!). I do believe that the earth will always have mysteries that we cant solve, but we can always try to solve them.
Wesley M Leonhardt's comment, October 1, 2013 5:41 PM
Chung, Emily. "Ancient Oxygen Discovery Shakes up History of Life on Earth - Technology & Science - CBC News." CBCnews. CBC/Radio Canada, 25 Sept. 2013. Web. 01 Oct. 2013. <http://www.cbc.ca/news/technology/ancient-oxygen-discovery-shakes-up-history-of-life-on-earth-1.1867976>.
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Dinosaurs = Birds: First Dinosaur Feathers Found in Ancient Amber

Dinosaurs = Birds: First Dinosaur Feathers Found in Ancient Amber | Amazing Science | Scoop.it
Paleontologists have figured out what ancient dino feathers and fuzz looked like, including color.

 

Instead of digging through rocks and rubble to find fossils, a group of Canadian paleontologists decided to dig through museums’ amber collections instead. Their unique approach paid off when they discovered feathers and never-before-seen structures, which they think are something called dinofuzz.


The researchers combed through thousands of minuscule amber nuggets from nearly 80 million years ago. Among them they found 11 M&M-sized globules with traces of ancient feathers and fuzz. A number resembled modern feathers—some fit for flying and others designed to dive. And unlike fossils, the amber preserved colors too: white, gray, red and brown.

 

But a few hollow hair-like structures stumped researchers. The unidentifiable filaments weren’t plant fibers, fungus or fur, so the researchers surmise that they are protofeathers (thought to be the evolutionary precursors to feathers). The collection is among the first to reveal all major evolutionary stages of feather development in non-avian dinosaurs and birds.


The unusual find suggests a wide array of plumed creatures populated the time period—sporting everything from seemingly modern feathers to their filament-like forebears—and that even by this early date, feathers had become specialized, for example, for diving underwater.

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The largest fish that ever lived

The largest fish that ever lived | Amazing Science | Scoop.it

An international team of scientists has uncovered the remains of the world's largest fish. The 50ft Leedsichthys problematicus swam the oceans of the Jurassic era more than 160m years ago, sweeping up shoals of plankton through giant, mesh-covered gills. Leedsichthys was eventually wiped out by the same catastrophe that killed the dinosaurs 66m years ago.

 

The discovery by the team – led by Professor Jeff Liston of the National Museums of Scotland – is intriguing because it reveals that just as dinosaurs on land were going through major changes which saw the appearance of animals of vast dimensions – creatures that included Diplodocus, Apatosaurus and Brachiosaurus – reptiles in the sea had also started to grow to vast proportions in the Jurassic.

 

"The process is known as gigantism," said Liston. "It was known about in land animals at the time but we had no way of knowing if a parallel process occurred in the oceans. We now know that it did – though the reason for appearance of these gigantic beasts, both on land and in the water, is not clear at present."

 

Pieces of Leedsichthys fossils were first found by the British collector Alfred Leeds in 1889. Similar remains were subsequently found at other sites, from northern Germany to Normandy, Mexico and the Atacama desert in Chile. However, knowledge of the fish remained sketchy because of the poor quality of these finds. Leedsichthys had a skeleton that was mostly made of cartilage and which does not fossilise easily. This paucity of evidence and lack of clarity about its dimensions led to the fish being given its second name: problematicus.

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165-million-year-old proto-mammal shows that traits like hair and fur originated well before the rise of mammals

165-million-year-old proto-mammal shows that traits like hair and fur originated well before the rise of mammals | Amazing Science | Scoop.it

A newly discovered fossil reveals the evolutionary adaptations of a 165-million-year-old proto-mammal, providing evidence that traits such as hair and fur originated well before the rise of the first true mammals. The biological features of this ancient mammalian relative, named Megaconus mammaliaformis, were described by scientists from the University of Chicago in the Aug 8, 2013 issue of Nature.

 

"We finally have a glimpse of what may be the ancestral condition of all mammals, by looking at what is preserved in Megaconus. It allows us to piece together poorly understood details of the critical transition of modern mammals from pre-mammalian ancestors," said Zhe-Xi Luo, professor of organismal biology and anatomy at the University of Chicago.

 

Discovered in Inner Mongolia, China, Megaconus is one of the best-preserved fossils of the mammaliaform groups, which are long-extinct relatives to modern mammals. Dated to be around 165 million years old,Megaconus co-existed with feathered dinosaurs in the Jurassic era, nearly 100 million years before Tyrannosaurus Rex roamed Earth.

 

Preserved in the fossil is a clear halo of guard hairs and underfur residue, making Megaconus only the second known pre-mammalian fossil with fur. It was found with sparse hairs around its abdomen, leading the team to hypothesize that it had a naked abdomen.

 

On its heels, Megaconus possessed a long keratinous spur, which was possibly poisonous. Similar to spurs found on modern egg-laying mammals, such as male platypuses, the spur is evidence that this fossil was most likely a male member of its species.

 

"Megaconus confirms that many modern mammalian biological functions related to skin and integument had already evolved before the rise of modern mammals," said Luo, who was also part of the team that first discovered evidence of hair in pre-mammalian species in 2006 (Science, 331: 1123-1127, DOI:10.1126/science.1123026).

 

A terrestrial animal about the size of a large ground squirrel, Megaconuswas likely an omnivore, possessing clearly mammalian dental features and jaw hinge. Its molars had elaborate rows of cusps for chewing on plants, and some of its anterior teeth possessed large cusps that allowed it to eat insects and worms, perhaps even other small vertebrates. It had teeth with high crowns and fused roots similar to more modern, but unrelated, mammalian species such as rodents. Its high-crowned teeth also appeared to be slow growing like modern placental mammals.

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Anela Leilani Kaiawe's curator insight, September 25, 2013 6:34 AM

this is a test run

Olivia Haltom's curator insight, December 6, 2013 6:44 AM

i think this is interesting because its talking anout an extinct animal from 165 million years ago.

Sydney Bolyard's curator insight, December 6, 2013 8:21 AM

This article reveals new found information stating that scientists have discovered a fossil of an animal (resembling a small squirrel), which leads to further discovery of evolution. The primary of form of evolution scientist are interested in are the adaptations of fur. Later in the article, it describes the hypothesis that scientists have formed as to what this newly discovered mammal's characteristics were likely to be. Any new discorvery of species is facinating because you figure how old the earth is and how long people have been around, and we are still finding new organisms.

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Ancient life, potentially millions of years old and barely alive, found 100 feet beneath ocean floor

Ancient life, potentially millions of years old and barely alive, found 100 feet beneath ocean floor | Amazing Science | Scoop.it
Researchers have found bacteria beneath the Pacific floor that may be thousands or millions of years old, their metabolism so slow that they’re basically in a state of suspended animation.

 

Call it survival of the slowest: Extraordinarily old, bizarrely low-key bacteria have been found in sediments 100 feet below the sea floor of the Pacific Ocean, far removed from sunlight, fresh nutrients and what humans would consider anything interesting to do.

 

Some of these organisms, scientists say, could be at least 1,000 years old. Or maybe millions of years. Their strategy for staying alive is to be barely alive at all. Their metabolism is dialed down to almost nothing, an adaptive advantage in a place with so few resources. The bacteria that survive are the ones that can satisfy themselves with minute traces of oxygen and a parsimonious diet of organic material laid down millions of years ago.

 

Such buried bacteria have been found before, but a new study, published Thursdayonline by the journal Science, has provided the clearest look at their glacial pace of existence. The conclusion, in short, is that microbes can putter along at extremely low rates of oxygen respiration, their numbers limited only by the paucity of energy available in the buried sediment.

 

“These organisms live so slowly that when we look at it at our own time scale, it’s like suspended animation,” said Danish scientist Hans Roy, a biologist at Aarhus University and the lead author of the study. “The main lesson here is that we need to stop looking at life at our own time scale.”

An ancillary message is that human beings should not be too chauvinistic about what constitutes, or characterizes, a living thing.

 

There are a lot more nuances to nature than scientists realized just a few decades ago.

 

The ingenuity of life gives hope to researchers looking for evidence of life beyond Earth. Extraterrestrial life could conceivably be detected by robotic probes, for example, in the Martian subsurface, or in an ice-
covered ocean on a cold moon farther out in the solar system.

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Researchers Sequence Partial Genome of 700,000 Year Old Horse

Researchers Sequence Partial Genome of 700,000 Year Old Horse | Amazing Science | Scoop.it

Genetic scientists have sequenced and analyzed short pieces of DNA preserved in bones from an early Middle Pleistocene horse that had been kept frozen for the last 700,000 years in permafrost at Thistle Creek, Yukon, Canada.

 

Unlike the small Ice Age horse fossils that are common across the unglaciated areas of the Yukon, Alaska and Siberia that date to the last 100,000 years, the Thistle Creek horse fossil found by Dr. Duane Froese from the University of Alberta was at least the size of a modern horse.

 

The scientists had dated the permafrost at the site from volcanic ashes in the deposits and knew that it was about 700,000 years old – representing some of the oldest known ice in the northern hemisphere. They also knew the fossil was similarly old.

 

They them extracted collagen from the fossil and found it had preserved blood proteins and that short fragments of ancient DNA were present within the bone.

 

The DNA showed that the horse fell outside the diversity of all modern and ancient horse DNA ever sequenced consistent with its geologic age. After several years of work, a draft genome of the horse was assembled and is providing new insight into the evolution of horses.

 

The study, reported in the journal Nature, showed that the horse fell within a line that includes all modern horses and the last remaining truly wild horses, the Przewalski’s Horse from the Mongolian steppes.

 

The 700,000-year-old horse genome – along with the genome of a 43,000-year-old horse Equus lambei, six present-day horses and a donkey – has allowed the team to estimate how fast mutations accumulate through time. In addition, the new genomes revealed episodes of severe demographic fluctuations in horse populations in phase with major climatic changes.

 

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Bizarre 500-Million-Year-Old Creature Unearthed

Bizarre 500-Million-Year-Old Creature Unearthed | Amazing Science | Scoop.it

A new fossilized, cigar-shaped creature that lived about 520 million years ago has been unearthed in Morocco.

 

The newfound species, Helicocystis moroccoensis, has "characteristics that place it as the most primitive echinoderm that has fivefold symmetry," said study co-author Andrew Smith, a paleontologist at the Natural History Museum in London, referring to the group of animals that includes starfish and sea urchins. Modern echinoderms typically have five-point symmetry, such as the five arms of the starfish or the sand dollar's distinctive pattern.

 

The primitive sea creature, described today (June 25) in the journal Proceedings of the Royal Society B, could even change its body shape from slender to stumpy. Researchers say it is a transitional animal that could help explain how early echinoderms evolved their unique body plans, Smith said.

 

H. moroccoensis, named after the country where it was found, had a cylindrical body that extended up to 1.6 inches (4 centimeters) long. The echinoderm's mouth was on the top of its body, and it sported a cup made of checkered plates with a small stem at its base. It had a latticelike skeleton made of calcite.

 

"It's a cigar-shaped beast, and it was able to expand and contract that cigar shape," Smith told LiveScience. "Sometimes it could be short and fat, and sometimes it could be long and thin."

 

The tiny sea creatures changed shape using a spiraling arrangement of five ambulacra, or grooves coming from the mouth that opened and closed to capture bits of food floating in the water.

 

The newly discovered species is the oldest known echinoderm with five ambulacra, and could shed light on how echinoderms evolved their unique body plans, Smith said.

 

H. moroccoensis was also found in sediments containing several other bizarre echinoderms, many of which had wacky body plans, ranging from completely asymmetrical to bilaterally symmetrical. That wide variety suggests the creatures were going through a period of dramatic diversification around that time period, Smith said.

 

"The important thing about the whole fauna is that there is already, by this time, a remarkable diversity in body form," Smith said. "And yet this is only 10 [million] to 15 million years after the calcite skeleton evolved."

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Russian scientists find frozen blood in mammoth carcass, boosting their chances of cloning

Russian scientists find frozen blood in mammoth carcass, boosting their chances of cloning | Amazing Science | Scoop.it

Russian scientists claimed Wednesday they have discovered blood in the carcass of a woolly mammoth, adding that the rare find could boost their chances of cloning the prehistoric animal. An expedition led by Russian scientists earlier this month uncovered the well-preserved carcass of a female mammoth on a remote island in the Arctic Ocean.

 

Semyon Grigoryev, the head of the expedition, said the animal died at the age of around 60 some 10,000 to 15,000 years ago, and that it was the first time that an old female had been found.

 

But what was more surprising was that the carcass was so well preserved that it still had blood and muscle tissue. "When we broke the ice beneath her stomach, the blood flowed out from there, it was very dark," Grigoryev, who is a scientist at the Yakutsk-based Northeastern Federal University, told AFP.

 

"This is the most astonishing case in my entire life. How was it possible for it to remain in liquid form? And the muscle tissue is also red, the colour of fresh meat," he added. Grigoryev said that the lower part of the carcass was very well preserved as it ended up in a pool of water that later froze over. The upper part of the body including the back and the head are believed to have been eaten by predators, he added.

 

"The forelegs and the stomach are well preserved, while the hind part has become a skeleton." The discovery, Grigoryev said, gives new hope to researchers in their quest to bring the woolly mammoth back to life.

 

"This find gives us a really good chance of finding live cells which can help us implement this project to clone a mammoth," he said. "Previous mammoths just have not had such well-preserved tissue."

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Ahmed Atef's comment, May 31, 2013 2:47 AM
i can do this cloning ;)
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52 million years ago, a rain forest grew on Antarctica

52 million years ago, a rain forest grew on Antarctica | Amazing Science | Scoop.it

Drilling of the seabed off Antarctica has revealed that rain forest grew on the frozen continent 52 million years ago, scientists said Thursday, warning it could be ice-free again within decades. The study of sediment cores drilled from the ocean floor off Antarctica's east coast revealed fossil pollens that had come from a "near-tropical" forest covering the continent in the Eocene period, 34-56 million years ago. Kevin Welsh, an Australian scientist who traveled on the 2010 expedition, said analysis of temperature-sensitive molecules in the cores had showed it was "very warm" 52 million years ago, measuring about 68 degrees F.

 

"There were forests existing on the land, there wouldn't have been any ice, it would have been very warm," Welsh said. "It's quite surprising, because obviously our image of Antarctica is that it's very cold and full of ice." Welsh said higher levels of carbon dioxide in the atmosphere were thought to be the major driver of the heat and ice-free conditions on Antarctica, with CO2 estimates of anywhere between 990 to "a couple of thousand" parts per million. CO2 is presently estimated at about 395ppm, and Welsh said the most extreme predictions by the Intergovernmental Panel on Climate Change would see ice again receding on Antarctica "by the end of the century.""It's difficult to say, because that's really controlled by people's and governments' actions," said Welsh, a paleoclimatologist from the University of Queensland.

 

"It really depends on how emissions go in the future." Welsh described the findings as "very significant" in understanding future climate change, particularly given how important Antarctica and the "very large" volume of water stored on its surface would be for the entire planet."It shows that if we go through periods of higher CO2 in the atmosphere, it's very likely that there will be dramatic changes on these very important areas of the globe where ice currently exists," he said.

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Jason, Charlie's curator insight, October 3, 2013 10:33 AM

This is represents the area and geography Antarctica.  This article explains that Antarctica had a rain forest grow in that part of the 34-56 million years ago.  Scientists say that this is an extraordinary find and that this could possibly happen in the next couple of decades.

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Velociraptor spider discovered in Oregon cave is so distinct it is placed its own family

Velociraptor spider discovered in Oregon cave is so distinct it is placed its own family | Amazing Science | Scoop.it

Scouring the caves of Southwest Oregon, scientists have made the incredible discovery of a fearsome apex predator with massive, sickle claws. No, it's not the Velociraptor fromJurassic Park: it's a large spider that is so unique scientists were forced to create a new taxonomic family for it. This is the first new spider family to be discovered in North America in over 130 years.

"This is something completely new," lead author of a paper on the species, Charles Griswold with the California Academy of Sciences, told SFGate. "It's a historic event."

The discoverers, who published their description paper in the open-access journalZoo Keyshave named thenew speciesTrogloraptor, which translates loosely to "cave robber," and they have dubbed a new spider family—Trogloraptoridae—to accommodate what they believe is a primitive spider. The full species name is Trogloraptor marchingtoniafter one of its discoverers.

 

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Dinosaurs Sat on Nests Like Birds, Pores in Egg Shells Reveal

Dinosaurs Sat on Nests Like Birds, Pores in Egg Shells Reveal | Amazing Science | Scoop.it

Dinosaurs laid eggs, of that there is no doubt. But what scientists haven't been as clear on is whether they brooded over their eggs like birds or buried them like crocodiles.

 

Now, a new study finds that at least one dino took a birdlike approach to hatching eggs. Troodon was a small, meat-eatingdinosaur that grew to be about 8 feet (2.4 meters) long. Thedinosaurs date back to the Late Cretaceous, about 75 million years ago, and they apparently incubated their eggs much like modern birds.

 

Most birds sit on their eggs to warm them, but crocodiles and their relatives completely bury their nests. The difference between the two shows up in the eggshells: Croc eggs have many pores to allow for air and water exchange, lest the eggs suffocate in their closed, humid nests. Bird eggs exposed to the air have fewer pores, because their eggs would be more in danger of drying out.

 

University of Calgary dinosaur researcher Darla Zelenitsky and Montana State University paleontologist David Varricchio studied Troodon egg clutches from Canada and Montana, examining the fossilized shells for signs of burial. They compared the porosity of the eggshells with that of eggshells from modern-day crocodiles, birds that nest by burying their eggs in mounds, and birds that nest by brooding, or sitting on their eggs. 

They found that porosity varied across the dino eggshell, suggesting the dinosaur laid its eggs almost vertically in sand or mud, but didn't bury the eggs completely. The adult would have had direct contact with the upper portions of these partially buried eggs, Varricchio said.

 

"There are similarities with a peculiar nester among birds called the Egyptian plover that broods its eggs while they're partially buried in sandy substrate of the nest," Varricchio said in a statement.

 

The plover, a wading bird, nests by laying its eggs in warm sand and then sitting on the nest with a wet belly, cooling the eggs from above.

The findings demonstrate that birdlike behavior evolved in theropods, the caste of bipedal dinosaurs related to today's birds, Zelenitsky said in a statement. The researchers reported their findings in the spring issue of the journal Paleobiology.

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Oldest dinosaur embryo fossils discovered in China

Oldest dinosaur embryo fossils discovered in China | Amazing Science | Scoop.it
Nesting site yields earliest known organic remains of a terrestrial vertebrate.

 

Palaeontologists working in China have unearthed the earliest collection of fossilized dinosaur embryos to date. The trove includes remains from many individuals at different developmental stages, providing a unique opportunity to investigate the embryonic development of a prehistoric species.

 

Robert Reisz, a palaeontologist at the University of Toronto in Mississauga, Canada, and his colleagues discovered the sauropodomorph fossils in a bone bed in Lufeng County that dates to the Early Jurassic period, 197 million to 190 million years ago. The site contained eggshells and more than 200 disarticulated bones — the oldest known traces of budding dinosaurs, the researchers report in Nature.

 

“Most of our record of dinosaur embryos is concentrated in the Late Cretaceous period,” says David Evans, curator of vertebrate palaeontology at the Royal Ontario Museum in Toronto. “This [study] takes a detailed record of dinosaur embryology and pushes it back over 100 million years.”

But it is not just the age of the fossils that is notable, the researchers say. Spectroscopic analysis of bone-tissue samples from the Chinese nesting site revealed the oldest organic material ever seen in a terrestrial vertebrate. That was surprising because the fossilized femur bones were delicate and porous, which made them vulnerable to the corrosive effects of weathering and groundwater, says Reisz.

 

“That suggests to us that other dinosaur fossils might have organic remains,” he says. “We just haven’t looked at them in the right ways.” 

Reisz thinks that the complex proteins his team detected in that organic material are preserved collagen. Because collagen composition varies across species, further analyses could help researchers to compare the sauropodomorph fossils with those of other creatures. They include the mighty sauropods, close relatives — and perhaps descendants — of early sauropodomorphs that weighed in at about 100,000 kilograms each, making them the largest animals ever to roam Earth.

 

The researchers think that the Lufeng dinosaurs are sauropodomorphs because they are similar in many ways to intact embryonic skeletons of Massospondylus, a sauropodomorph that Reisz unearthed in South Africa in 20052. But their analysis does identify key differences between the two fossil finds. The Lufeng embryos were less developmentally advanced than the Massospondylus embryos, and they seem to be examples of a different genus, Lufengosaurus.

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New fossils push the origin of flowering plants back by 100 million years to the early Triassic era

New fossils push the origin of flowering plants back by 100 million years to the early Triassic era | Amazing Science | Scoop.it
Drilling cores from Switzerland have revealed the oldest known fossils of the direct ancestors of flowering plants.

 

Flowering plants evolved from extinct plants related to conifers, ginkgos, cycads, and seed ferns. The oldest known fossils from flowering plants are pollen grains. These are small, robust and numerous and therefore fossilize more easily than leaves and flowers.

An uninterrupted sequence of fossilized pollen from flowers begins in the Early Cretaceous, approximately 140 million years ago, and it is generally assumed that flowering plants first evolved around that time. But the present study documents flowering plant-like pollen that is 100 million years older, implying that flowering plants may have originated in the Early Triassic (between 252 to 247 million years ago) or even earlier.

 

Many studies have tried to estimate the age of flowering plants from molecular data, but so far no consensus has been reached. Depending on dataset and method, these estimates range from the Triassic to the Cretaceous. Molecular estimates typically need to be "anchored" in fossil evidence, but extremely old fossils were not available for flowering plants. "That is why the present finding of flower-like pollen from the Triassic is significant," says Prof. Peter Hochuli, University of Zurich.

 

Peter Hochuli and Susanne Feist-Burkhardt from Paleontological Institute and Museum, University of Zürich, studied two drilling cores from Weiach and Leuggern, northern Switzerland, and found pollen grains that resemble fossil pollen from the earliest known flowering plants. With Confocal Laser Scanning Microscopy, they obtained high-resolution images across three dimensions of six different types of pollen.

 

In a previous study from 2004, Hochuli and Feist-Burkhardt documented different, but clearly related flowering-plant-like pollen from the Middle Triassic in cores from the Barents Sea, south of Spitsbergen. The samples from the present study were found 3000 km south of the previous site. "We believe that even highly cautious scientists will now be convinced that flowering plants evolved long before the Cretaceous," say Hochuli.

 

What might these primitive flowering plants have looked like? In the Middle Triassic, both the Barents Sea and Switzerland lay in the subtropics, but the area of Switzerland was much drier than the region of the Barents Sea. This implies that these plants occurred a broad ecological range. The pollen's structure suggests that the plants were pollinated by insects: most likely beetles, as bees would not evolve for another 100 million years.

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Paleoclimatology: Three Major Rivers Existed in the Sahara 100,000 Years Ago

Paleoclimatology: Three Major Rivers Existed in the Sahara 100,000 Years Ago | Amazing Science | Scoop.it

Simulating paleoclimates in the Sahara region, a team of researchers from Germany and United Kingdom has found evidence of three major river systems that likely existed in North Africa about 130,000 – 100,000 years ago, but are now largely buried by dune systems in the desert. The image shows Irharhar, Sahabi and Kufrah rivers systems in the Sahara region. The green points show the location of archaeological sites in the region.

 

When flowing, these rivers – Irharhar, Sahabi and Kufrah – likely provided fertile habitats for animals and vegetation, creating ‘green corridors’ across the region. At least one river system is estimated to have been 100 km wide and largely perennial.

 

The Irharhar river, westernmost of the three identified, may represent a likely route of human migration across the region. In addition to rivers, new simulations predict massive lagoons and wetlands in northeast Libya, some of which span over 70,000-square kilometers.

 

“It’s exciting to think that 100,000 years ago there were three huge rivers forcing their way across a 1,000 km of the Sahara desert to the Mediterranean and that our ancestors could have walked alongside them,” said Dr Tom Coulthard of the University of Hull, UK, who is a lead author of the study published in the journal PLoS ONE.

 

Previous studies have shown that people traveled across the Saharan mountains toward more fertile Mediterranean regions, but when, where and how they did so is a subject of debate. Existing evidence supports the possibilities of a single trans-Saharan migration, many migrations along one route, or multiple migrations along several different routes.

 

The existence of ‘green corridors’ that provided water and food resources were likely critical to these events, but their location and the amount of water they carried is not known. The simulations provided in this study aim to quantify the probability that these routes may have been viable for human migration across the region.

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Dinosaur-killing asteroid was a twin

Dinosaur-killing asteroid was a twin | Amazing Science | Scoop.it

Asteroids 2, dinosaurs 0. The infamous space rock that slammed into Earth and helped wipe it clean of large dinosaurs may have been a binary – two asteroids orbiting each other.

 

The dino-killing asteroid is usually thought of as a single rock with a diameter of 7 to 10 kilometres, but it may really have been two widely separated rocks with that combined diameter.

 

The surprise conclusion comes from a re-evaluation of the proportion of asteroid craters on Earth that were formed from binary impacts. It could also spell bad news for those hoping to protect our world from catastrophic collisions in future.

 

Earth bears the scars of twin-asteroid impacts: the Clearwater Lakes near Hudson Bay in Canada, for instance, are really twin craters that formed about 290 million years ago. Examples like Clearwater are rare, though. Just 1 in 50 of craters on Earth come in such pairs.

 

That is a puzzle because counts of the rocks zooming around in the vicinity of Earth suggest binaries are far more common. "It's been known for 15 years that about 15 per cent of near-Earth asteroids are binary," says Katarina Miljković at the Institute of Earth Physics in Paris, France. All else being equal, 15 per cent of Earth's impact craters should be the result of twin impacts. Why does the real figure appear so much lower?

 

Miljković and her colleagues have found an explanation. They ran computer simulations of binary asteroids hitting Earth and found that they often form a single crater.

 

This makes sense, given that a crater can be 10 times the diameter of the asteroid that made it. The team found that only unusual cases involving two small, widely separated asteroids are guaranteed to form a pair of distinct craters. The researchers' simulations confirmed that such binary asteroids are rare enough to explain why paired craters account for only 2 per cent of all Earth's craters.

 

An obvious implication is that binary asteroids hit Earth more often than the crater record appears to suggest – with ramifications for efforts to prevent future impacts.

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Amazing Science: Paleontology Postings

Amazing Science: Paleontology Postings | Amazing Science | Scoop.it

Paleontology is the scientific study of prehistoric life and includes the study of fossils to determine organisms' evolution and interactions with each other and their environments. Paleontology lies on the border between biology and geology, and shares with archaeology a border that is difficult to define. It now uses techniques drawn from a wide range of sciences, including biochemistry, mathematics and engineering. Use of all these techniques has enabled paleontologists to discover much of the evolutionary history of life, almost all the way back to when Earth became capable of supporting life, about 3,800 million years ago.

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New evidence surfaces that cosmic impact caused Younger Dryas extinctions 12,900 years ago

New evidence surfaces that cosmic impact caused Younger Dryas extinctions 12,900 years ago | Amazing Science | Scoop.it

A period of rapid, intense cooling, known as the Younger Dryas, took place about 13,000 years ago. Scientists think this sudden change in climate caused the extinction of many large mammals, such as the mammoth, and was the reason for the disappearance of North America's Clovis people. According to one hypothesis, a cosmic impact caused the climate to cool. Using data from the Greenland ice core, Michail Petaev and his colleagues at Harvard University have found what appears to be evidence of this impact.

Measurements of oxygen isotopes in the Greenland ice core show that around 13,000 years ago an episode of rapid cooling, which lasted about 1,000 years, occurred. During this time, many megafauna became extinct and evidence of the Clovis people, one of the earliest human societies to inhabit the Americas, disappeared from the archeological record.

Now Petaev's team claims to have uncovered evidence of a cosmic impact at the Younger Dryas boundary. When examining samples from Greenland Ice Sheet Project 2 (GISP2), they found that platinum concentration increased by about 100 times approximately 12,900 years ago.

Platinum/iridium and platinum/aluminum ratios were very high, indicating that the platinum probably did not have a terrestrial source. While most volcanic rocks have high Pt/Ir ratios, their Pt/Al ratios are low. Mantle rocks have low levels of aluminum, but their Pt/Ir ratios are much lower than that measured in the ice core.

On the other hand, Pt/Ir and Pt/Al ratios in magmatic iron meteorites are very high, suggesting that the platinum found in the ice core came from a meteor.

Debris from a cosmic impact would have caused the climate to cool so quickly that species would have been unable to adapt, leading to their extinction. The Clovis people would not have been able to cope with the catastrophic changes to their environment.

 

The research lends support to recent claims that a sedimentary layer containing iridium grains and glass-like carbon with nanodiamonds, found at many northern hemisphere sites around the Younger Dryas boundary, is evidence of a meteor impact.

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39,000-year-old Frozen Woolly Mammoth on Display in Japan

A frozen woolly mammoth named Yuka goes on display in Japan. The female was found in Russia and was 10 years old when she died. Scientists have made several unsuccessful attempts to revive the species. But mammoth expert Norihisa Inuzuka says Yuka should provide more information about these creatures.

Norihisa Inuzuka, mammoth expert, saying (Japanese): "With this, we can dig deeper into the reasons why species became extinct and apply the lessons learnt to the human race which might be facing its own dangers of extinction. I think it can help us learn to reflect more deeply about our own existence."


What makes the carcass special is that it is extraordinarily well-preserved with presence of liquid blood in it along with pink flesh and fur. The blood, according to scientists, could be used to clone the animal.


"When we broke the ice beneath her stomach, the blood flowed out from there, it was very dark. This is the most astonishing case in my entire life. How was it possible for it to remain in liquid form? And the muscle tissue is also red, the colour of fresh meat," Semyon Grigoryev, the head of the expedition that found Yuki said.

 

Yuka's lower part is well-preserved as it ended up in a swamp before it froze, but its head along with back show signs of gnawing, Grigoryev added.

 

Mammoths are an extinct group of elephants that belong to the genus Mammuthus. Their ancestors had migrated from Africa about 3.5 million years back. The most famous of these ancient elephants is the woolly mammoth Mammuthus primigenius, which is a close cousin of the modern elephant. The woolly mammoth appeared in the northeastern Siberia around 400,000 years back and was well-adapted to cold with dense fur, short ears and a dense undercoat.

 

The exhibition runs from July 13th to September 16th.

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How oxygen came into existence on earth: Caltech researchers have found evidence of a precursor photosystem involving manganese that predates cyanobacteria

How oxygen came into existence on earth: Caltech researchers have found evidence of a precursor photosystem involving manganese that predates cyanobacteria | Amazing Science | Scoop.it

For most terrestrial life on Earth, oxygen is necessary for survival. But the planet's atmosphere did not always contain this life-sustaining substance, and one of science's greatest mysteries is how and when oxygenic photosynthesis—the process responsible for producing oxygen on Earth through the splitting of water molecules—first began. Now, a team led by geobiologists at the California Institute of Technology (Caltech) has found evidence of a precursor photosystem involving manganese that predates cyanobacteria, the first group of organisms to release oxygen into the environment via photosynthesis.  

 

The findings, outlined in the June 24, 2013, early edition of the Proceedings of the National Academy of Sciences (PNAS), strongly support the idea that manganese oxidation—which, despite the name, is a chemical reaction that does not have to involve oxygen—provided an evolutionary stepping-stone for the development of water-oxidizing photosynthesis in cyanobacteria.

 

"Water-oxidizing or water-splitting photosynthesis was invented by cyanobacteria approximately 2.4 billion years ago and then borrowed by other groups of organisms thereafter," explains Woodward Fischer, assistant professor of geobiology at Caltech and a coauthor of the study. "Algae borrowed this photosynthetic system from cyanobacteria, and plants are just a group of algae that took photosynthesis on land, so we think with this finding we're looking at the inception of the molecular machinery that would give rise to oxygen."

 

Photosynthesis is the process by which energy from the sun is used by plants and other organisms to split water and carbon dioxide molecules to make carbohydrates and oxygen. Manganese is required for water splitting to work, so when scientists began to wonder what evolutionary steps may have led up to an oxygenated atmosphere on Earth, they started to look for evidence of manganese-oxidizing photosynthesis prior to cyanobacteria. Since oxidation simply involves the transfer of electrons to increase the charge on an atom—and this can be accomplished using light or O2—it could have occurred before the rise of oxygen on this planet.

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3 Billion Year Old Plankton Microfossils Found in Australia

3 Billion Year Old Plankton Microfossils Found in Australia | Amazing Science | Scoop.it

Scientists have recently found oddly spindle-shaped microfossils in 3 billion year old rock in Australia.“It is surprising to have large, potentially complex fossils that far back,” said study lead author Prof Christopher House from Penn State University.

 

The microfossils are reported to be planktonic autotrophs who were approximately twenty to sixty microns in length– and freely floated through out the ocean producing energy, according to the study published in the journal Geology. The researchers looked at surrounding rocks (Farrel Quartzite) to determine the age of the fossils, and came up with their stable carbon isotope ratios.

 

The ratio of Carbon 13 (The component used to determine the age of life by measuring the half-lives of isotopes) was indicative of life. Life forms throughout life gather up more carbon 12 to incorporate into themselves which creates a certain signature of biological processes. Researchers looked at surrounding rock to determine if it was a fluke, and indeed the surrounding area was different from the microfossils.

 

“The spindles appear to be the same as those found in rocks from the Strelly Pool Formation in Western Australia and the Onverwacht Group in South Africa and Swaziland that are both 3.4 billion years old,” said co-author Dr Dorothy Oehler from Astromaterials Research and Exploration Science Directorate, NASA – Johnson Space Center.

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Green Sahara: research points to an abrupt climate shift in the Sahara 5,000 years ago

Green Sahara: research points to an abrupt climate shift in the Sahara 5,000 years ago | Amazing Science | Scoop.it

As recently as 5,000 years ago, the Sahara — today a vast desert in northern Africa, spanning more than 3.5 million square miles — was a verdant landscape, with sprawling vegetation and numerous lakes. Ancient cave paintings in the region depict hippos in watering holes, and roving herds of elephants and giraffes — a vibrant contrast with today’s barren, inhospitable terrain.


The Sahara’s “green” era, known as the African Humid Period, likely lasted from 11,000 to 5,000 years ago, and is thought to have ended abruptly, with the region drying back into desert within a span of one to two centuries. 

Now researchers at MIT, Columbia University and elsewhere have found that this abrupt climate change occurred nearly simultaneously across North Africa. The team traced the region’s wet and dry periods over the past 30,000 years by analyzing sediment samples off the coast of Africa. Such sediments are composed, in part, of dust blown from the continent over thousands of years: The more dust that accumulated in a given period, the drier the continent may have been.



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100-Million-Year-Old Spider Attack Preserved in Amber

100-Million-Year-Old Spider Attack Preserved in Amber | Amazing Science | Scoop.it

Looks like this 100-million-year old spider didn’t get to enjoy its final meal. Trapped in a piece of amber, the juvenile spider appears to be on the cusp of devouring a male wasp that was caught in its web. Such a grisly scene between spider and prey has never before been found in the fossil record.

 

The amazing snapshot shows an event that occurred in the Early Cretaceous period, about 97 to 110 million years ago, in the Hukawng Valley of Myanmar, “almost certainly with dinosaurs wandering nearby,” as the press release about this discovery reports. The spider is a social orb-weaver spider, formally known as "Geratonephila burmanica", and its victim is a wasp of the species Cascoscelio incassus. Both species are extinct today but the fossil suggests that insect behavior from the past is not too different from the present.

 

Related wasp species are known to parasitize spider eggs, so there is some poetic justice in the spider’s attack. “This was the wasp’s worst nightmare, and it never ended. The wasp was watching the spider just as it was about to be attacked, when tree resin flowed over and captured both of them,” said entomologist George Poinar Jr. of Oregon State University in the release.

 

This latest fossil doesn’t just capture the dramatic spider attack but also evidence of spider social life in the Early Cretaceous. Another spider, an adult male, is captured some distance away in the amber, co-habiting on the same web as the juvenile. Males of modern-day social orb-weavers are typically found living on female-constructed webs, where they assist in capturing insects and maintaining the web.

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Climate change, not human activity, led to megafauna extinction

Climate change, not human activity, led to megafauna extinction | Amazing Science | Scoop.it
Most species of gigantic animals that once roamed Australia had disappeared by the time people arrived, a major review of the available evidence has concluded.

 

The research challenges the claim that humans were primarily responsible for the demise of the megafauna in a proposed "extinction window" between 40,000 and 50,000 years ago, and points the finger instead at climate change.

 

An international team led by the University of New South Wales, and including researchers at the University of Queensland, the University of New England, and the University of Washington, carried out the study. It is published in the Proceedings of the National Academy of Sciences.

 

"The interpretation that humans drove the extinction rests on assumptions that increasingly have been shown to be incorrect. Humans may have played some role in the loss of those species that were still surviving when people arrived about 45,000 to 50,000 years ago -- but this also needs to be demonstrated," said Associate Professor Stephen Wroe, from UNSW, the lead author of the study.

 

"There has never been any direct evidence of humans preying on extinct megafauna in Sahul, or even of a tool-kit that was appropriate for big-game hunting," he said.

 

About 90 giant animal species once inhabited the continent of Sahul, which included mainland Australia, New Guinea and Tasmania.

 

"These leviathans included the largest marsupial that ever lived -- the rhinoceros-sized Diprotodon - and short-faced kangaroos so big we can't even be sure they could hop. Preying on them were goannas the size of large saltwater crocodiles with toxic saliva and bizarre but deadly marsupial lions with flick-blades on their thumbs and bolt cutters for teeth," said Associate Professor Wroe.

 

The review concludes there is only firm evidence for about 8 to 14 megafauna species still existing when Aboriginal people arrived. About 50 species, for example, are absent from the fossil record of the past 130,000 years.

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Marco Bertolini's curator insight, May 7, 2013 12:21 AM

Des scientifiques sont à présent certains qu'un changement climatique a détruit la mégafaune d'Australie.  Et non pas l'action humaine, comme on l'a longtemps cru.  Un avertissement ?

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Late-Holocene Bird Extinction Linked to Human Colonization

Late-Holocene Bird Extinction Linked to Human Colonization | Amazing Science | Scoop.it
A new research suggests that more than 1,000 bird species became extinct on Pacific islands following human colonization.

 

Scientists had long known extinction rates in the region were high but estimates varied from 800 to 2,000 bird species. The researchers led by Prof Tim Blackburn of the University of Tennessee studied the extinction rates of nonperching land birds on Pacific islands from 700 to 3,500 years ago. They used fossil records from 41 Pacific islands such as Hawaii and Fiji to run an analytical technique called the Bayesian mark-recapture method. This allowed them to model gaps in the fossil record for more than 300 Pacific islands and estimate the number of unknown extinct species.

 

“We used information on what species are currently on the islands and what species are in the fossil record to estimate the probability of finding a species in the fossil record,” said co-author Prof Alison Boyer, also from the University of Tennessee.

 

The team found that nearly 983, or two-thirds, of land bird populations disappeared between the years of the first human arrival and European colonization. Disappearances are linked to overhunting by people, forest clearance and introduced species.

 

“We calculate that human colonization of remote Pacific islands caused the global extinction of close to a thousand species of nonperching land birds alone,” Prof Boyer said. “However, it is likely there are more species that were affected by human presence. Sea bird and perching bird extinctions will add to this total.”

 

Species lost include several species of moa-nalos, large flightless waterfowl from Hawai’i, and the New Caledonian Sylviornis, a relative of the game birds but which weighed in at around 30 kg, three times as heavy as a swan.

 

The researchers found the extinction rates differed depending on island and species characteristics. For example, larger islands had lower rates of extinction because they had larger populations of each bird species. Islands with more rainfall also had lower extinction rates because they experienced less deforestation by settlers. Bird species that were flightless and large-bodied had a higher rate of extinction because they were easier and more profitable to hunt and their lower rates of population growth inhibited recovery from overhunting or habitat loss.

 

“Flightless species were 33 times more likely to go extinct than those that could fly,” Prof Boyer explained. “Also, species that only populated a single island were 24 more times likely to go extinct than widespread species.”

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Deborah Verran's comment, April 13, 2013 3:39 PM
This image of the moa is one of the birds that became extinct in New Zealand after colonization. The adult birds were taller than humans.