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Origin of birds as modified dinosaurs

Origin of birds as modified dinosaurs | Amazing Science |

Geneticist Arkhat Abzhanov on Archosaurs, paedomorphosis, and the evolution of birds

One of the biggest challenges in evolutionary biology is trying to understand the origin of true novelties. Some of these novelties, innovations in evolution, are also called key innovations because they allow a group of organisms to take over a whole ecological niche and expand well beyond their ancestors.

Birds are one of the most successful groups of animals on our planet. There are over ten thousand species, dozens of families and orders of birds, and they can be found almost anywhere on this planet.

To understand the evolution of birds, we need to look at the history of the entire lineage of Archosauria which began back in the Triassic era. About 250 million years ago, reptiles separated into two major groups. One group (called Squamata) stayed small eating mainly small prey such as insects. These are the ancestors of modern day lizards and snakes . The other group was large and consumed large prey. This group is called Archosauria and they tended to dominate the ecological systems in which they lived and occupied for hundreds of millions of years. Their close relatives today are crocodiles and birds. The Archosaurs also gave rise to Pterosaurs, the flying reptiles, which were highly successful during their time but died out.

Paedomorphosis is a phenomenon of evolution where a change in timing of developments can cause interesting morphological changes. Paedomorphosis can be seen when descendant adults resemble the juveniles of their own ancestors. There are actually two different ways to become paedomorphic. One of them is called neoteny. One famous example is salamanders like the axolotl. Even though the axolotl looks like a larva, it is actually a sexual mature adult salamander. That’s neoteny when your somatic development is retarded relative to your sexual development. You develop very slowly and at the time you are mature you still look like a larva.

The other way to become paedomorphic is called progenesis and that’s basically what all the birds are doing today. In progenesis your body is developing normally but you become sexual mature much-much faster. In modern-day songbirds it takes just a few weeks for them to become sexual mature. It takes only about two weeks for a robin to look like an adult, so, by the time it is ready to fly just off the nest it looks very similar to its adult parents.

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Hyoid bone analysis supports hypothesis that Neanderthals could talk

Hyoid bone analysis supports hypothesis that Neanderthals could talk | Amazing Science |

Could Neanderthals talk? The latest X-ray analysis conducted at the Elettra Sincrotrone Trieste research center (Italy) on the hyoid bone of a Neanderthal Man found in 1989 on the archaeological site of Kebara (Israel), strongly supports this hypothesis. The paper was published in the international journal Plos One, and presents the results of a comparison between the biomechanical properties of the Kebara hyoid and those of the same bone in Homo sapiens. The study was conducted by an international research team with members from Elettra, the University of Chieti and ICTP (Unesco) in Italy, the University of New England and of New South Wales in Australia, and the University of Toronto in Canada.

Scholars dealing with the question of complex language and its evolution, already had focused their attention on the hyoid bone. This is the only bone of the vocal tract and therefore the only part that can fossilize. The hyoid provides support to the larynx and serves as anchor for the tongue and other muscles needed - at least in Homo sapiens - in phonation. It is already known, from the study of external morphology, that the hyoid bones of Homo neanderthalensis and modern man don't differ significantly, as they have a different shape from that of other primates such as chimpanzees. "This observation," says Ruggero D'Anastasio, paleontologist at the University of Chieti, "while being compatible with the use of language by this species of Homo that lived between two hundred and thirty thousand years ago, is in no way sufficient. To be able to say something about the function of the hyoid bone, it was crucial to analyze its internal microstructure, which remodels in response to the mechanical stress to which the bone is subjected."

"Although we plan to analyze other hyoids to further increase the significance of the data," says D' Anastasio, "I believe that this work represents a decisive step forward supporting the hypothesis that the Neanderthals were using complex language. Our results confirm in fact that the hyoid bone of the two species had the same type of biomechanical usage. That this also corresponds to the same function—that is speech—it really seems the most reasonable conclusion. Our results, added to other evidence coming from paleontology, archaeology and paleogenetics, goes in the same direction. The use of pigments, the subdivision of residential areas into zones, the use of animal remains (for instance feathers) as personal ornament and other behaviors that can be interpreted as forms of complex comunication, were attributed before only to Homo sapiens, but recently they have been been confirmed also for the Neanderthals. All this adds up to conclude that our ancestors could actually talk."

"Maybe the Neanderthals could also sing and dance to the sound of music," adds Claudio Tuniz, physicist Claudio Tuniz of the Abdus Salam International Centre for Theoretical Physics in Trieste "as suggested by our recent studies on the flute made from the femur of a bear, found in Slovenia on a site that was frequented by Neanderthals 60 millennia ago."

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Giants of the sky: Argentavis

Giants of the sky: Argentavis | Amazing Science |

With a wingspan estimated at seven meters across,‭ ‬Argentavis was roughly twice the size of the largest flying bird today‭ (‬Wandering Albatross‭)‬,‭ ‬and only the long extinct pterosaurs could have rivaled and exceeded it for size.‭ ‬How such a large bird like Argentavis could fly has been the key area of study associated with this bird,‭ ‬something that has resulted in some interesting conclusions.‭ ‬The first is that the keel of the breastbone is quite small which suggests the main flight muscles were reduced when compared to other flying birds.‭ ‬This means that even though the wings were huge,‭ ‬Argentavis did not have the stamina to continuously flap them.‭ 

It’s most likely that as a result of these under developed muscles Argentavis relied upon prevailing wind currents to keep itself aloft with flapping only occurring during the take-off and landing phases.‭ ‬This would see Argentavis using its large wings to exploit a combination of thermal up draughts‭ ‬as well as dynamic soaring.‭ ‬Dynamic soaring is essentially where a flying creature uses the boundary between two air masses to pick up speed by cartwheeling into oncoming wind and using the wind speed to accelerate itself forward.‭ ‬Repeating this process further increases the speed of the bird and resulting effect of the next manoeuvre resulting in an extremely energy efficient form of flight,‭ ‬one that is now even used by human glider pilots to stay airborne longer.

Argentavis also seems to have relied more upon air currents for taking off as the immense size of its wings means that it could not flap them when outstretched without the tips hitting the ground.‭ ‬Instead Argentavis would have had an easier time just stretching out its wings and facing into the oncoming wind.

‬From this position Argentavis could run into the prevailing wind to get air moving across its wing surfaces and then use its legs to jump up into the air.‭ ‬This would be the most critical time for Argentavis as getting airborne is not the same as staying airborne‭ (‬ask any pilot‭)‬.‭ ‬However, if Argentavis had positioned itself to run down a slope it could have gotten itself airborne while increasing the distance between itself and the ground just by flying horizontally level.‭ ‬Argentavis could then flap its wings while it adjusted its course to take better advantage of the air currents.‭

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First ever comet material found originating from a comet that struck Earth 28 million years ago

First ever comet material found originating from a comet that struck Earth 28 million years ago | Amazing Science |
A team in South Africa has discovered the first definitive evidence of a comet strike on Earth some 28 million years ago.

A team in South Africa has discovered the first definitive evidence of a comet strike on Earth some 28 million years ago. It’s believed to have blown up over what is now Egypt, heating up the Sahara sand to a temperature of up to 2000 degrees Celcius, annihilating everything in its path.

“Comets are unique, comets are extraordinary because they carry very pristine material from our outer solar system and well beyond. So, you literally have a travelling chemical factory, which enters our Earth’s atmosphere and explodes. The comet explodes, it shatters glass, it creates glass – molten glass – there is this lake of fire which creates a blast area of 6,000 square kilometers,” says Professor David Block.

A specimen of the glass is on display in Johannesburg, together with an unusual rock collected in the Sahara 20 years ago. It is filled with microscopic black diamonds, believed to be part of a comet’s nucleus.

The core of a comet is made up of material formed at the same time as our own solar system four and a half billion years ago. Scientists hope this discovery could help unlock some of the secrets of the formation of our solar system.

NASA and ESA (European Space Agency) generally spend billions of dollars in designing spacecraft which can either send an impactor into the very nucleus of a comet. I think the incredible point about this discovery too is that you don’t need to go into space to collect the material, the material is right here,” said Professor Block.

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Dinosaur-Killing Comet Didn't Wipe Out Freshwater Species

Dinosaur-Killing Comet Didn't Wipe Out Freshwater Species | Amazing Science |

New research shows freshwater organisms fared better than others after the most recent extinction event.


The mass extinction event the scientists studied (also the most recent and most familiar) is known as the K-T event or, more recently, the K-Pg event. The disaster, which killed off at least 75 percent of all species on Earth, including all dinosaurs except for birds, was apparently triggered by a cosmic impact that occurred in what is now Mexico about 65 million years ago.


Past research suggested that while marine life was devastated by this mass extinction, freshwater organisms underwent relatively low extinction rates. Now investigators suggest the secret of their survival may have been all the variability experienced by freshwater life.


Water would have helped shelter life in rivers and lakes, as well as the seas and oceans, from the initial blast of heat from the cosmic impact. However, the giant extraterrestrial collision set fire to Earth's surface, darkening the sky with dust and ash that cooled the planet. The resulting "impact winter" and its lack of sunlight would have crippled both freshwater and marine food chains by killing off microscopic photosynthetic organisms known as phytoplankton that are at the base of the marine and freshwater food chains.


Intriguingly, while marine communities were devastated by the mass extinction, losing 50 percent of their species, geophysicist Douglas Robertson at the University of Colorado at Boulder and his colleagues looked at a database of western North America fossils and discovered freshwater ones there survived relatively unscathed, losing only about 10 percent of their species.


The researchers note that freshwater organisms, unlike marine life, are used to annual freezes that ice over inland waters, severely limiting their oxygen supplies. As such, freshwater communities might have better endured the low oxygen levels in the wake of the death of photosynthetic life following an impact winter. 

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Siats meekerorum: Large predatory dinosaur fossils found similar in size with T. rex

Siats meekerorum: Large predatory dinosaur fossils found similar in size with T. rex | Amazing Science |
Paleontologists announced today the discovery of a new predatory dinosaur that lived in what is modern-day Utah around 100 million years ago.


“This dinosaur was a colossal predator second only to the great Tyrannosaurus rex and perhaps Acrocanthosaurus in the North American fossil record,” said Dr Lindsay Zanno from the North Carolina Museum of Natural Sciences and the Field Museum of Natural History, the lead author on the paper published in the journal Nature Communications.

The prehistoric giant is named Siats meekerorum. The genus name, Siats, refers to a cannibalistic monster from the mythology of the Ute Native American people. Its specific name acknowledges the Meeker family for their support for early career paleontologists at the Field Museum.


Siats meekerorum was over 9 meters long and weighed more than 4 tons. Despite its large size, the dinosaur is not a close relative of Tyrannosaurus rex and other tyrannosaurs. Rather, it belongs to the carcharodontosaurian group of theropods, whose more famous members include giants like the Argentinean Giganotosaurus. Siats meekerorum belongs to a branch of the carcharodontosaurian family tree that was previously unknown in North America.


“We were thrilled to discover the first dinosaur of its kind in North America and add to mounting evidence that dinosaurs were widely dispersed across the globe 100 million years ago” said Dr Peter Makovicky of the Field Museum of Natural History, who is a co-author of the discovery paper.


Siats meekerorum comes from the middle of a 30-million-year gap in the fossil record of North American large predatory dinosaurs, during which the top predator role changed hands from carcharodontodsaurians in the Early Cretaceous to tyrannosaurs in the Late Cretaceous.

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Trapped seawater discovered near the Chesapeake Bay is up to 150 million years old

Trapped seawater discovered near the Chesapeake Bay is up to 150 million years old | Amazing Science |

Not only is the Chesapeake Bay so enormous it can be seen from space, it essentially came from outer space. An asteroid or huge chunk of ice slammed into Earth about 35 million years ago, splashing into the Early Cretaceous North Atlantic, sending tsunamis as far as the Blue Ridge Mountains and leaving a 56-mile-wide hole at the mouth of what is now the bay.


But a newly published research paper written by U.S. Geological Survey scientists shows that wasn’t the end of it. While drilling holes in southern Virginia to study the impact crater, the scientists discovered “the oldest large body of ancient seawater in the world,” a survivor of that long-gone sea, resting about a half-mile underground near the bay, according to the USGS.


“What we essentially discovered was trapped water that’s twice the salinity of modern seawater,” said Ward Sanford, a USGS hydrologist. “In our attempt to find out the origin, we found it was Early Cretaceous seawater. It’s really water that’s from the North Atlantic.”


The findings showing that the water is probably between 100 million and 150 million years old were published in the journal Nature.


The Chesapeake Bay Impact Crater was discovered in 1999 by a tandem of USGS and Virginia Department of Environmental Quality scientists.


They theorized that a huge rock or chunk of ice slammed into an ancient ocean, sending enormous pieces of debris skyward and forcing monster tsunamis hundreds of miles inland.


Over centuries, the crater became hidden under 400 to 1,200 feet of sand, silt and clay, hampering its discovery for decades. “It’s the largest crater discovered so far in the United States, and it’s one of only a few oceanic impact craters that have been documented worldwide,” USGS hydrologist David Powars said at the time.

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The truth about T. rex: Even the most well known dinosaur kept some secrets

The truth about T. rex: Even the most well known dinosaur kept some secrets | Amazing Science |

In late 1905, newspaper reporters gushed over the bones of a prehistoric monster that palaeontologists had unearthed in the badlands of Montana. When The New York Times described the new 'Tyrant saurian', the paper declared it “the most formidable fighting animal of which there is any record whatsoever”. In the century since, Tyrannosaurus rex has not loosened its grip on the imaginations of the public or palaeontologists.

Stretching more than 12 meters from snout to tail and sporting dozens of serrated teeth the size of rail spikes, the 66-million-year-old T. rex remains the ultimate example of a prehistoric predator — so much so that a media frenzy erupted this year over a paper debating whether T. rex predominantly hunted or scavenged its meals. This infuriated many palaeontologists, who say the matter was resolved long ago by ample evidence showing that T. rex could take down prey and dismantle carrion. What particularly vexed researchers was that this non-issue overshadowed other, more important questions about T. rex.

The dinosaur's evolutionary origins, for example, are still a mystery. Researchers are eagerly trying to determine how these kings of the Cretaceous period (which spanned from 145 million to 66 million years ago) arose from a line of tiny dinosaurs during the Jurassic period (201 million to 145 million years ago). There is also considerable debate about what T. rex was like as a juvenile, and whether palaeontologists have spent decades mistaking its young for a separate species. Even the basic appearance of T. rex is in dispute: many researchers argue that the giant was covered in fluff or fuzz rather than scales. And then there is the vexing question of why T. rex had such a massive head and legs but relatively puny arms.

In the first few decades after palaeontologist Henry Fairfield Osborn named and described T. rex, researchers viewed this giant dinosaur as the culmination of a trend towards bigger predators. In this view, T. rex was seen as the descendent of Allosaurus, a 9-meter-long predator that lived more than 80 million years earlier. These and other massive carnivorous dinosaurs were lumped together in a categorical wastebasket called the Carnosauria, with T. rex as the last and biggest of the ferocious family. But palaeontologists tore up that evolutionary tree when they started using a more rigorous form of analysis called cladistics in the 1990s. They re-examined relationships between dinosaur groups and found that T. rex had its roots in a lineage of small, fuzzy creatures that lived in the shadow of Allosaurus and other predators during the Jurassic period.


The view that emerged placed T. rex and its close relatives — together known as tyrannosaurids — as the top twig on a broader evolutionary bush called the Tyrannosauroidea, which emerged around 165 million years ago. Among the earliest known members of this group was Stokesosaurus clevelandi, a bipedal carnivore 2–3 meters long that lived about 150 million years ago. Little is known about this creature, but evidence from other early tyrannosauroids suggests that Stokesosaurus had a long, low skull and slender arms. Early tyrannosauroids were small, agile predators, but their size placed them low in the pecking order during the Jurassic. “They were more lapdogs than top predators,” says Brusatte.

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Gathering Gondwana: New Look at an Ancient Puzzle

Gathering Gondwana: New Look at an Ancient Puzzle | Amazing Science |
New study hopes to settle a debate over Gondwana's breakup.


Dinosaurs roamed, mammals started to flourish, the first birds and lizards evolved, and a massive supercontinent began to split apart on Earth about 180 million years ago. Yet, the details of the breakup of one of the largest landmasses in history have stumped scientists until now.


The breakup of the supercontinent Gondwana eventually formed the continents in the Southern Hemisphere. Exactly how this happened has been debated by geologists for years. Most theories say Gondwana broke into many different pieces, but new research suggests the large land mass simply split in two.


 Researcher Graeme Eagles of the University of London said he was suspicious of the theory that Gondwana had divided into many smaller continents because it was inconsistent with what is known about all other supercontinent breakups, including the breakup of Pangea into Gondwana and Laurasia.


Other continents in the geologic past, such as Rodinia, the oldest known continent, and Pangea, followed a pattern of splitting along tectonic lines into fewer, larger pieces, geologists think. Eagles wondered if a similar process could explain the breakup of Gondwana.


By studying data from where the continent first began to fracture, he determined that Gondwana split into eastern and western plates. Then, about 30 million years later, as crocodiles and sharks were evolving, the two plates split apart, and one continent became two.


Before it cracked into several landmasses, Gondwana included what are today Africa, South America, Australia, India and Antarctica. The big continents — Africa and South America — split off about 180 million to 170 million years ago. In recent years, researchers have debated what happened next, as the remaining continents rocketed apart. For example, different Gondwana reconstruction models had a 250-mile (400 kilometers) disagreement in the fit between Australia and Antarctica, an error that has a cascading effect in plate reconstructions, said Lloyd White, a geologist at Royal HollowayUniversity in Surrey, England.


With a series of computer models, the scientists tested various best fits for Australia, Antarctica and India against the compiled research data. The winner was an old-school approach, first published in the 1980s, White said. The big picture shows India, Australia and Antarctica were all joined about 165 million years ago. India started to pull away from Antarctica, first breaking away from both continents by about 100 million years ago. It zoomed north, eventually smashing into Asia. Australia and Antarctica opened up like a zipper from west to east between 85 million to 45 million years ago, White said. When the last "tooth" broke, south of Tasmania, Australia rocketed northward.

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Clawed fossil had spider-like brain: Best-preserved nervous system discovered in an ancient fossil

Clawed fossil had spider-like brain: Best-preserved nervous system discovered in an ancient fossil | Amazing Science |

Dating back 520 million years, the clawed spider-like fossil shows clear evidence of a brain and of nerve cords running through the creature's trunk. The specimen now confirms that the ancestors of spiders and scorpions were related, but branched off more than half-a-billion years ago. The "great appendage" arthropods, are an extinct group of joint-legged creatures with large claw-like appendages - or growths - protruding from their heads. The nervous system tends to be similar between major groups of animals, which helps palaeontologists work out how they are related, explained Greg Edgecombe from the Natural History Museum in London.

New to science, the fossil was recently discovered in South China and is part of the genus Alalcomenaeus. This group had segmented bodies equipped with about a dozen pairs of appendages which enabled the creatures to swim or crawl. It was placed in a CT scanner and compared with other arthropods in order to understand its evolution. The team then used 3D software to see structures not visible on the surface of the fossil.

The fossil belongs to an extinct group of marine arthropods known as megacheirans, Greek for "large claws". To infer the evolutionary relationships between species, the fields of palaeontology and neuroanatomy together.

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First Fossil of Blood-Filled Mosquito Discovered

First Fossil of Blood-Filled Mosquito Discovered | Amazing Science |

Through a series of events that scientists themselves admit was “extremely improbable,” a mosquito that feasted on the blood of Eocene animals some 46 million years ago managed to die and become trapped in sediment, but remain in tact, all while carrying a belly full of blood — its last meal.


The result, recently discovered in some oil shale from northwestern Montana, is the first fossil of a mosquito found still engorged with ancient blood. According to the lead researcher of the study, Smithsonian Institution paleontologist Dale Greenwalt, this is only the fifth instance of blood-eating, or hematophagy, by any insect to be revealed in the fossil record, and it’s the first in a mosquito with traces of blood that his team calls “incontrovertible.”

Most fossils of blood-eating insects that have been found are of midges, a kind of biting fly, trapped in amber, the team points out. But since mosquitoes typically prefer open habitats near water, rather than forests full of sap-bearing trees, finding preserved remains of mosquitoes has been rare. Given all of these factors, Greenwalt’s team writes, “it is not surprising that a fossil of a blood-engorged mosquito has not been described [before]; this despite the popular misconception of dinosaur DNA recovery from blood-engorged mosquitoes in amber popularized by the 1993 movie Jurassic Park.”

Since they bring that up, it’s worth pointing out that the mosquito fossil dates to the Middle Eocene, some 19 million years after non-avian dinosaurs went extinct. DNA molecules are too complex and fragile to survive fossilization, the team says, so it’s impossible to tell what kind of animal the Montana mosquito took its final meal from.

But among the discoveries that this find has made possible is that other large molecules — like those large enough to denote the presence of blood — can still survive fossilization.


The team decided to investigate the fossil more closely after noticing the insect’s dark, distended abdomen, appearing much like a modern mosquito after drinking a big blood meal. Tests of the abdomen revealed very high levels of iron ions, a mineral in which animal blood is rich.

So the team analyzed the sample using mass spectroscopy to get a more precise chemical makeup of the insect’s gut contents. They found telltale organic compounds that are the “fingerprints” of a substance called heme, the molecule that allows hemoglobin in blood to carry oxygen, and that gives blood its red color.


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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 |

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 |

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.

Wesley M Leonhardt's comment, October 1, 2013 8:34 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 8:39 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 8:41 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. <>.
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To bird or not to bird? The Archaeopteryx debate continues

To bird or not to bird? The Archaeopteryx debate continues | Amazing Science |

In 2012, the controversial case over whether or not Archaeopteryx lithographica, perhaps the most iconic dinosaur species of all time, was a bird was settled. Apparently. (free pdf) This was an important analysis for two reasons. Firstly, it countered a previous study showing that Archaeopteryx was more closely related to dinosaurs like Velociraptor and Deinonychus, and secondly used advanced, sort of non-traditional methods in palaeontology, called maximum likelihood and Bayesian analysis, to work out its relationships. None of this is news. It was extensively covered upon release way back, and also revisited recently with the discovery of Aurornis xuiwhich was found to be the most basal bird (i.e., that which was closest to the origin of the group, typically known as Avialae, or Aves).

Now a new study, from the December issue of a journal called Cladistics, has re-examined the data from the 2012 study, asking the question of whether or not the analyses they used even made sense to do in the first place. This is actually quite important. Maximum Likelihood and Bayesian analysis where designed with models in mind for describing the evolution of nucleotide data, that is genetic sequence data. Whether or not they can actually be used in fossil data, or that which is based purely on anatomy, is questionable, as anatomical features, or characters, evolve in a different manner to genetic data (e.g., there aren’t anytransversions or transitions). Given how often now these methods are used for genetic data, and to great effect, it’s a bit weird that it seems to have been largely overlooked by palaeontologists and scientists who use morphology to reconstruct evolutionary relationships.

Usually, palaeontologists use a method called parsimony analysis, which is a much simpler model for generating evolutionary trees. To use any of the programs below, download one of the nexus files from here (dinosaurs!), and run it with the program – worth a fiddle for a bit of science-ing!

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Extinct Giant Moa Bird Loses Weight, Strength, in New Study

Extinct Giant Moa Bird Loses Weight, Strength, in New Study | Amazing Science |
The giant moa may have been tall, but it was not as hefty or strong boned as previous research has suggested, according to a new analysis of a full-body skeleton.

The scientific name of the giant moa — Dinornis robustus — translates to "robust strange bird," and the species was the largest of at least nine moa bird species that roamed New Zealand's jungles and shrublands for thousands of years, until going extinct about 500 years ago, likely due to overhunting. The giant birds looked much like ostriches and emus do today; but their skeletal remains show they would have towered over their cousins, reaching about 12 feet (3.7 meters) tall, which is nearly double the height of modern ostriches.

Moa may have been hunted to extinction within a century of human arrival to New Zealand. Moa made such easy prey that by AD 1200 the hunting of Moa alone provided food surpluses sufficient to provide for the settling of large villages up to 3 hectares. These villages were permanent coastal encampments from which bands would set out on several week hunts to slaughter and carry back Moa. Over 300 Moa butchering sites are known, 117 on South Island which together account for some 100,000-500,000 Moa. With such abundance came a good deal of waste: as much as 50% of usable weight was discarded in the field. At around the same time as hunting was at it peak, the forests of South Island were burned off. The extraordinary abundance of food resources supported a population of as many as 10,000 people. However, by the late 1400s the Moa hunting society collapsed. By about A.D. 1400 all moa are generally thought to have become extinct, along with the Haast's Eagle which had relied on them for food. Recent research using carbon-14 dating of middens strongly suggests that this took less than a hundred years.

The kiwi were formerly regarded as the closest relatives of the moa, but comparisons of their DNA in a paper published in 2005 suggested moa were more closely related to the Australian emu and cassowary. However research published in 2010 found that the moa's closest cousins were not the emu and cassowary but smaller terrestrial South American birds called the tinamous which are able to fly.

The Dinornis seem to have had the most pronounced degree of sexual dimorphism, with females being up to 150% as tall and 280% as heavy as males. The females were so much bigger that they were classified as separate species until 2003.

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Chicxulub Dinosaur impact could have sent Earth life to Mars, study finds

Chicxulub Dinosaur impact could have sent Earth life to Mars, study finds | Amazing Science |

Panspermia - the idea that organisms can "hitchhike" around the solar system on comets and debris from meteor strikes - has long fascinated astronomersBut thanks to advances in computing, astrobiologists are now able to simulate these journeys and follow potential stowaways as they hitch around the Solar System.

In this new study, researchers first estimated the number of rocks bigger than 3m ejected from Earth by major impacts. Perhaps the most famous of these impacts was at Chicxulub in Mexico about 66 million years ago - when an object the size of a small city collided with Earth. The impact has been blamed for the mass extinction of the dinosaurs, triggering volcanic eruptions and wildfires which choked the planet with smoke and dust. It also launched about 70 billion kg of rock into space - 20,000kg of which could have reached Juper moon Europa. And the chances that a rock big enough to harbor life arrived are "better than 50/50", researchers estimate. Could Earthlings be swimming in the icy oceans of Europa?


Earth rocks big enough* to support life made it to:

  • Venus 26,000,000 rocks
  • Mercury 730,000
  • Mars 360,000
  • Jupiter 83,000
  • Saturn 14,000
  • Io 10
  • Europa 6
  • Titan 4
  • Callisto 1

*3m diameter or larger.


Three meters is the minimum they think necessary to shield microbes from the Sun's radiation over a journey lasting up to 10 million years. They then mapped the likely fate of these voyagers. Many simply hung around in Earth orbit, or were slowly drawn back down.

Others were pulled into the Sun, or sling-shotted out of the Solar System entirely. Yet a small but significant number made it all the way to alien worlds which might welcome life. About six rocks even made it as far as Europa, a satellite of Jupiter with a liquid ocean covered in an icy crust. But could living organisms actually survive these epic trips? 

"We find that rock capable of carrying life has likely transferred from both Earth and Mars to all of the terrestrial planets in the solar system and Jupiter," says lead author Rachel Worth, of Penn State University.

On Mars, there is little evidence of flowing water during the last 3.5bn years - the likeliest window for Earth life to arrive.

The first space travellers? Bacterial endospores can survive for millions of years. But what if the reverse trip took place? The early Martian atmosphere appears to have been warm and wet - prime conditions for the development of life.

And if Martian microbes ever did exist, transfer to Earth is "highly probable" due to the heavy traffic of meteorites between both planets.

"Billions have fallen on Earth from Mars since the dawn of our planetary system. It is even possible that life on Earth originated on Mars," says Ms. Worth. While her team are not the first to calculate that panspermia is possible, their 10-million-year simulation is the most extended yet, said astrobiologist Prof. Jay Melosh, of Purdue University. "The study strongly reinforces the conclusion that, once large impacts eject material from the surface of a planet such as the Earth or Mars, the ejected debris easily finds its way from one planet to another", he says.

"The Chicxulub impact itself might not have been a good candidate because it occurred in the ocean (50 to 500m deep water) and, while it might have ejected a few sea-surface creatures, like ammonites, into space, it would not likely have ejected solid rocks. "I sometimes joke that we might find ammonite shells on the Moon from that event.

"But other large impacts on the Earth may indeed have ejected rocks into interplanetary space." Another independent expert on panspermia, Mauricio Reyes-Ruiz of the National Autonomous University of Mexico, said the new findings were "very significant".

"The fact such different pathways exist for the interchange of material between Earth and bodies in the Solar System suggests that if life is ever found, it may very well turn out to be our very, very distant relatives," he said.

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The world’s oldest astronomers: Scientists use ancient trees to look back on the history of our local cosmos

The world’s oldest astronomers: Scientists use ancient trees to look back on the history of our local cosmos | Amazing Science |
Scientists in Japan use ancient trees to look back on the history of our local cosmos, and discover a mystery.


Since the invention of the telescope in the year 1608, mankind has collected information about our local cosmos. As it turns out, we’re not the only ones. Trees have been doing the same for millennia.


A group of physicists led by Nagoya University graduate student Fusa Miyake has begun using information stored in ancient Japanese cedars to gain the oldest firsthand accounts of the local universe. They have discovered, hidden within tree rings, clear evidence of some surprisingly high-energy events—possibly supernovae or solar flares—that occurred more than 1200 years ago.


On Japan’s Yakushima island, trees regularly live at least a thousand years, thriving under the tree equivalent of a low-carb diet in the form of a low-nutrition granite bedrock that encourages a slower pace of growth. Miyake and her team examined core samples from two trees on this small island. Back at Nagoya University, they studied the number and thickness of the tree’s rings not just to determine the age of the trees but also to gather information about the atmosphere they breathed.

When high-energy radiation from space enters Earth’s upper atmosphere, it interacts with naturally occurring atmospheric molecules to produce the isotope carbon-14. As trees are firmly plugged into the earth’s carbon cycle by photosynthesis, the carbon-14 ends up in each tree ring, creating an annual record etched into the flesh of the tree of the average carbon-14 level in Earth’s atmosphere.


Miyake and her colleagues had good reason to focus on the rings corresponding to 775 AD. A previous project called IntCal, which uses tree records of carbon-14 levels to calibrate carbon-14 dating, had seen a noticeable rise in carbon-14 levels toward the end of the 8th century.

The signal Miyake’s team found was far above anything seen in recent times, indicating that Earth had been bombarded by an extremely intense burst of radiation. The rings revealed that, over the course of one year, the atmospheric level of carbon-14 rose 1.2 percent: nearly 20 times the normal variation.


This massive flash of radiation could have been caused by a supernova; a gamma ray burst from a supremely rare galactic event such as a collision of two neutron stars; or a super solar flare at least 10 times the size of the largest observed flare.


Using their knowledge of earth sciences, biology and astronomy, Miyake’s team uncovered a smoking gun in a cosmological whodunit. Now all that remains is to identify who fired that gun.

Abel Farias's curator insight, December 2, 2013 5:38 PM

You can find history in any object. Whenever archeologists look for new fossils they are looking for a something that tells them a story. In this article they talk about how tree rings explain how the environment was during the life of the tree. I would use this article in Chemistry class during the Carbon Dating unit. It shows how recent day scientist used carbon dating to make a new discovery

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Did highly acidic rain cause the end-Permian mass extinction?

Did highly acidic rain cause the end-Permian mass extinction? | Amazing Science |

Rain as acidic as undiluted lemon juice may have played a part in killing off plants and organisms around the world during the most severe mass extinction in Earth’s history. 

About 252 million years ago, the end of the Permian period brought about a worldwide collapse known as the Great Dying, during which a vast majority of species went extinct.

The cause of such a massive extinction is a matter of scientific debate, centering on several potential causes, including an asteroid collision, similar to what likely killed off the dinosaurs 186 million years later; a gradual, global loss of oxygen in the oceans; and a cascade of environmental events triggered by massive volcanic eruptions in a region known today as the Siberian Traps. 

Now scientists at MIT and elsewhere have simulated this last possibility, creating global climate models of scenarios in which repeated bursts of volcanism spew gases, including sulfur, into the atmosphere. From their simulations, they found that sulfur emissions were significant enough to create widespread acid rain throughout the Northern Hemisphere, with pH levels reaching 2 — as acidic as undiluted lemon juice. They say such acidity may have been sufficient to disfigure plants and stunt their growth, contributing to their ultimate extinction.

“Imagine you’re a plant that’s growing happily in the latest Permian,” says Benjamin Black, a postdoc in MIT’s Department of Earth, Atmospheric and Planetary Sciences. “It’s been getting hotter and hotter, but perhaps your species has had time to adjust to that. But then quite suddenly, over the course of a few months, the rain begins to sizzle with sulfuric acid. It would be quite a shock if you were that plant.”

The group simulated 27 scenarios, each approximating the release of gases from a plausible volcanic episode, including medium eruptions, large eruptions, and magma erupted through explosive pipes in the Earth’s crust. The researchers included a wide range of gases in their simulations, based on estimates from chemical analyses and thermal modeling. They then tracked water in the atmosphere, and the interactions among various gases and aerosols, to calculate the pH of rain.

In addition to acid rain, the researchers modeled ozone depletion resulting from volcanic activity. While ozone depletion is more difficult to model than acid rain, their results suggest that a mix of gases released into the atmosphere may have destroyed 5 to 65 percent of the ozone layer, substantially increasing species’ exposure to ultraviolet radiation. The greatest ozone depletion occurred near the poles. 

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Fossilized insects prove: Mating technique has remained unchanged for 165 million years

Fossilized insects prove: Mating technique has remained unchanged for 165 million years | Amazing Science |

Permanently linked lovers suggest species' mating technique has remained unchanged for eons.


The moment the petite mort becomes a grand mort has been captured again. This pair of tiny insects — 15-millimetre-long froghoppers (Anthoscytina perpetua) from the Middle Jurassic — has now joined the ranks of animals fossilized at the moment of sexual intercourse.


Dong Ren, curator of insect fossils at the Capital Normal University in Beijing, and his colleagues scoured more than 1,200 fossilized froghopper specimens from Inner Mongolia and found only one pair of permanently linked lovers.

Although it will doubtless be scant consolation to these two individuals locked together belly to belly, they have become the oldest known fossil of copulating insects, reports Ren's team inPLoS ONE. And they suggest that froghoppers do not favour sexual experimentation: modern relatives of these ancient animals still mate using a similar choreography.


Or, as Ren and his team write, the animals’ “genitalic symmetry and mating position have remained static for over 165 million years”.

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First laser scan of a 40 meter-long skeleton of the vast Cretaceous Argentinosaurus dinosaur

First laser scan of a 40 meter-long skeleton of the vast Cretaceous Argentinosaurus dinosaur | Amazing Science |
One of the world’s largest dinosaurs has been digitally reconstructed by experts from The University of Manchester allowing it to take its first steps in over 94 million years.

The Manchester team, working with scientists in Argentina, were able to laser scan a 40 metre-long skeleton of the vast Cretaceous Argentinosaurus dinosaur. Then using an advanced computer modeling technique involving the equivalent of 30,000 desktop computers they recreated its walking and running movements and tested its locomotion ability tested for the very first time.

Dr. Bill Sellers, lead researcher on the project from the University’s Faculty of Life Sciences, said: “If you want to work out how dinosaurs walked, the best approach is computer simulation. This is the only way of bringing together all the different strands of information we have on this dinosaur, so we can reconstruct how it once moved.”


Dr. Lee Margetts, who also worked on the project, said: “We used the equivalent of 30,000 desktop computers to allow Argentinosaurus to take its first steps in over 94 million years.

“The new study clearly demonstrates the dinosaur was more than capable of strolling across the Cretaceous planes of what is now Patagonia, South America.”


The team of scientists included Dr. Rodolfo Coria from Carmen Funes Museum, Plaza Huincal, Argentina, who was behind the first physical reconstruction of this dinosaur that takes its name from the country where it was found. The dinosaur was so big it was named after a whole country.


Dr. Phil Manning, from Manchester who contributed to the paper, said: “It is frustrating there was so little of the original dinosaur fossilized, making any reconstruction difficult. The digitization of such vast dinosaur skeletons using laser scanners brings Walking with Dinosaurs to life…this is science not just animation.”

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Bees Underwent Massive Extinction When Dinosaurs Did

Bees Underwent Massive Extinction When Dinosaurs Did | Amazing Science |

For the first time ever, scientists have documented a widespread extinction of bees that occurred 65 million years ago, concurrent with the massive event that wiped out land dinosaurs and many flowering plants.

Previous studies have suggested a widespread extinction among flowering plants at the K-T boundary, and it’s long been assumed that the bees who depended upon those plants would have met the same fate. Yet unlike the dinosaurs, “there is a relatively poor fossil record of bees,” says Rehan, making the confirmation of such an extinction difficult.


Rehan and colleagues overcame the lack of fossil evidence for bees with a technique called molecular phylogenetics. Analyzing DNA sequences of four “tribes” of 230 species of carpenter bees from every continent except Antarctica for insight into evolutionary relationships, the researchers began to see patterns consistent with a mass extinction. Combining fossil records with the DNA analysis, the researchers could introduce time into the equation, learning not only how the bees are related but also how old they are.


“The data told us something major was happening in four different groups of bees at the same time,” says Rehan, of UNH’s College of Life Sciences and Agriculture. “And it happened to be the same time as the dinosaurs went extinct.”


While much of Rehan’s work involves behavioral observation of bees native to the northeast of North America, this research taps the computer-heavy bioinformatics side of her research, assembling genomic data to elucidate similarities and differences among the various species over time. Marrying observations from the field with genomic data, she says, paints a fuller picture of these bees’ behaviors over time.


“If you could tell their whole story, maybe people would care more about protecting them,” she says. Indeed, the findings of this study have important implications for today’s concern about the loss in diversity of bees, a pivotal species for agriculture and biodiversity.


“Understanding extinctions and the effects of declines in the past can help us understand the pollinator decline and the global crisis in pollinators today,” Rehan says.

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New Approach to Explaining Evolution’s Big Bang

New Approach to Explaining Evolution’s Big Bang | Amazing Science |

Scientists Still Trying to Explain Evolution's Big Bang Theory. One of the explanations is the "Great Uniformity", a worldwide stratigraphic feature marking a divide between continental crystalline basement rock and younger shallow marine sedimentary deposits. Occasionally — in the Grand Canyon, for example — it is exposed on Earth's surface to dramatic effect. Geologists have been debating the origins and the global impact of the Great Unconformity ever since the term was coined in 1869. Shanan Peters and Robert Gaines presented an analysis of stratigraphic and lithologic data from 830 locations in North America, together with petrologic and geochemical data. They find evidence that the formation of the Great Unconformity caused enhanced continental weathering and increased oceanic alkalinity and ionic strength in expanding shallow seas, which in turn triggered biomineralization and the Cambrian explosion of marine animals.

Via CarlaB
CarlaB's curator insight, September 19, 2013 8:53 PM

Natural Sciences!

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Early Humans—Not Climate Change—Decimated Africa’s Largest Carnivores

Early Humans—Not Climate Change—Decimated Africa’s Largest Carnivores | Amazing Science |

Millions of years ago Africa's large carnivores were much more diverse than they are today, both in terms of the number of species that existed and of the ecological roles they played.


Fossil analyses show that the decline began more than two million years ago, around the same time that early members of our genus, Homo, started eating more meat.


The timing suggests that competition with humans for access to prey may have driven large carnivores to extinction, potentially triggering a cascade of other ecological changes.

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120-million-year-old bird had not one but two tails

120-million-year-old bird had not one but two tails | Amazing Science |
A 120-million-year-old bird sported not one, but two tails, National Geographic reported.


The second-oldest known bird, Jeholornis, lived in what is today China along with other feathered prehistoric animals. Fossils show the Jeholornis was the size of a turkey, had claws on its winged forelimbs with three small teeth in its lower jaw.


Now, paleontologists are looking at the rear end of the large birds. They not only possess a long-fan feathered tail but also a second tail frond.


"The 'two-tail' plumage of Jeholornis is unique," according to a study published in the Proceedings of the National Academy of Sciences. The study was led by Jingmai O’Connor of the Chinese Academy of Sciences in Beijing.


Much like today's male peacocks which sport colorful feathers to attract their mates, the study suggests only male Jeholornis had the eye-catching tail fronds.


"Clearly the display aspect of the frond would have been undeniable," says paleontologist Mark Norell, of the American Museum of Natural History in New York, who was not part of the study. "It calls to mind living birds, even peacocks, which display broad plumes of feathers."

Via Kathy Bosiak
Wesley M Leonhardt's comment, October 15, 2013 9:35 AM
120 million years ago, birds had two tails. Fossils have proven that bird Jeholornis had two tails. This is a big discovery when it comes to birds.
Wesley M Leonhardt's comment, October 15, 2013 9:37 AM
I think it is really cool, and weird, that birds had two tails. I've never heard of any type of animal that had two tails. It's just weird.
Wesley M Leonhardt's comment, October 15, 2013 9:38 AM
"120-million-year-old Bird Had Two Tails." Fox News. FOX News Network, 9 Oct. 2013. Web. 15 Oct. 2013. <>.
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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 |
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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