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Gondwanaland
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Erosion of vast mountain range led to explosion of early life
Oxygen that allowed complex organisms to first flourish, hundreds of millions of years ago, came from the 'extreme erosion' of Earth's largest ever mountain range, geologists have found.
The mountain range, was 8,000 km long and spanned the ancient supercontinent of Gondwanaland around 600 million years ago.
The mountains coincided with the time when life evolved from simple, single-celled organisms, into a myriad of bizarre, soft-bodied animals. These strange creatures, known as the Ediacaran fauna, first appeared 575 million years ago, and included some animals up to two metres long.

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In a paper published in this months Geophysical Journal International, Dr Graeme Eagles from the Earth Sciences Department at Royal Holloway, University of London, reveals how one of the largest continents ever to exist met its demise.
Gondwana was a supercontinent that existed between 500 and 180 million years ago. For the past four decades, geologists have debated how Gondwana eventually broke up, developing a multitude of scenarios which can be loosely grouped into two schools of thought one theory claiming the continent separated into many small plates, and a second theory claiming it broke into just a few large pieces. Dr Eagles, working with Dr Matthais König from the Alfred Wegener Institute for Polar and Marine Research in Bremerhaven, Germany, has devised a new computer model showing that the supercontinent cracked into two pieces, too heavy to hold itself together.

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Cambrian Explosion
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University of Maryland geologist Alan Jay Kaufman and his department of geology colleagues long have been tracking and elucidating the rise of oxygen on Earth and its intimate connection with the development and evolution of life. In a new paper to be published today in the Proceedings of the National Academy of Sciences (online Early Edition in the week of February 25 - 29) Kaufman and an international team of scientists from Virginia Tech, University of Nevada at Las Vegas, and Chinese Academy of Sciences provide evidence that the rise of oxygen and the oxidation of deep oceans between 635 and 551 million years ago likely had an impact on the increase and spread of the earliest complex life, including animals.

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Burgess Shales
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Geologists at the University of Leicester have solved a puzzle found in rocks half a billion years old.
Some of the most important fossil beds in the world are the Burgess Shales in the Canadian Rockies. Once an ancient sea bed, they were formed shortly after life suddenly became more complex and diverse the so-called Cambrian explosion and are of immense scientific interest.
Normally, only hard parts of ancient animals became fossilised; the bones, teeth or shells. Soft parts were rarely preserved: many plants and invertebrate animals evolved, lived for millions of years and became extinct, but left no trace in the fossil record. The Burgess Shales preserved soft tissue in exquisite detail, and the question of how this came to happen has troubled scientists since the discovery of the fossils in 1909.
Now, painstaking work by Sarah Gabbott and Jan Zalasiewicz of the University of Leicester, with Desmond Collins of the Royal Ontario Museum, has provided an answer. They analysed the shales millimetre by millimetre, and found that unlike most rocks of this type, they werent slowly deposited, mud flake by mud flake. Instead, a thick slurry powered down a steep slope and instantly buried the animals to a depth where normal decay couldnt occur.

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Rheic Ocean
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A wealth of information on one of Earth's ancient oceans is now available in a single volume published by the Geological Society of America. The Evolution of Rheic Ocean: From Avalonian-Cadomian Active Margin to Alleghenian-Variscan Collision addresses long-standing controversies surrounding the ocean's origin, paleogeography, and ultimate closure.
The Rheic Ocean was one of the dominant oceans of the late Paleozoic. Approximately 420 million years ago it separated two large land masses: the supercontinent Gondwana, consisting of present-day South America, Africa, India, Australia, and Antarctica; and Laurussia, made up of North America, Greenland, Europe, and part of Asia.

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Cambrian explosion
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A team of scientists led by young Croatian evolutionary geneticist Tomislav Domazet-Loo from Ruder Bokovic Institute (RBI) in Zagreb, Croatia, have developed a new methodological approach in evolutionary studies. Using the method they named 'genomic phylostratigraphy', its authors shed new and unexpected light on some of the long standing macroevolutionary issues, which have been puzzling evolutionary biologists since Darwin.

The only direct method of research in evolutionary history involves analysing the fossil remains of once living organisms, excavated in various localities throughout of the world. However, that approach often cannot provide the full evolutionary pathway of some species, as it requires uncovering of many fossils from various stages of its evolutionary history. As the fossil record is imperfect, the evolution research fundamentally hinges on luck factor in discovering the adequate palaeontological sites.
However, the RBI team proposed a novel and interesting approach to bypass this obstacle. Namely, they suggested that the genome of every extant species carries the snapshots of evolutionary epochs that species went trough. What's even more important, they also developed the method which enables evolution researchers to readily convert those individual 'snapshots into the full-length 'evolutionary movie' of a species.
Applying their new methodology on the fruit fly genomic data they tackled some of the most intriguing evolutionary puzzles - some of which distressed even Darwin himself. First, they demonstrated that parts of the living organism exposed to the environment so called ectoderm - are more prone to evolutionary changes. Further, they explained the evolutionary origin of the germ layers, the primary tissue forms that form during the first days after the conception of a new animal, and from which subsequently all other tissues are developed. Finally, they discovered the potential genetic trigger for the 'Cambrian explosion', a major global evolutionary event on the planet, when some 540 million years ago almost all animal forms known today suddenly 'appeared'.

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RE: Gondwana
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newearth1
Credit Christina Ullman / Ohio University
This graphic shows what scientists previously thought Earth looked like 420 million years ago (at left), and the revised map (at right) based on new evidence uncovered in southern Mexico.

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Appalachian Mountain range
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Geologists have developed a new theory to explain how and when the Appalachian Mountain range was created. Their research redraws the map of the planet from 420 million years ago.
The scientists recently discovered a piece of the Appalachian Mountains in southern Mexico, a location geologists long had assumed was part of the North American Cordillera. The Cordillera is a continuous sequence of mountain ranges that includes the Rocky Mountains. It stretches from Alaska to Mexico and continues into South America.
For the past decade, geologists have collected information from Mexico's Acatlán Complex, a rock outcropping the size of Massachusetts. As they uncovered each new piece of data from the complex, evidence contradicting earlier assumptions about the origins of that part of Mexico emerged.
According to the conventional map of 420 million years ago, two main land masses were separated by the Rheic Ocean. In the south sat Gondwana, a supercontinent consisting of South America, Africa, India, Australia and Antarctica. To the north was Laurussia, made up of North America, Greenland, Europe and part of Asia. The old map showed the Acátlan Complex attached to Laurussia. The complex broke off Gondwana about 80 million years earlier, drifted toward North America along with the other land masses, closing an older ocean, known as the Iapetus Ocean, as it did so. The collision created the Appalachian Mountains.
The new map looks rather different.
Evidence collected by Nance and his colleagues from rocks in the Acatlán Complex shows that its collision with Laurussia actually occurred about 120 million years later. The rocks once existed on an ancient ocean floor, but this ocean has proven to be the Rheic, not Iapetus as previously thought.
The explanation is that the Acatlán Complex was originally attached to Gondwana. Gondwana and the complex eventually slammed into North America, closing the Rheic Ocean in the process. This cataclysmic crunch of continental plates formed the goliath land mass known as Pangea, and created the Appalachian Mountains.

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Australian researchers believe they have discovered evidence that an 8000km-long 'supermountain range' as high as the Himalayas was the source of life on Earth

The range spanned the prehistoric supercontinent Gondwana, which later fragmented to form present-day Australia, Africa, Antarctica, New Zealand, South America and Arabia said Rick Squire of Melbourne's Monash University School of Geosciences.
Dr Squire was studying the formation of a gold deposit at the Stawell mine in western Victoria with three other researchers when the group made the discovery.
The four, including the University of Melbourne's Professor Chris Wilson and Australian National University researchers Ian Campbell and Charlotte Allen, were examining what qualities in the region's sandstone helped create the gold deposit.
The researchers were dating zircon, a mineral in the stone, using a spectrometer.

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See Cambrian explosion

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Joint Russian and German bottom survey of World ocean's southern part near the Drake Passage resulted in discovery of the previously unknown vast underwater plateau Pirie.

Scientists from Russian Institute of Geochemistry and Analytical Chemistry and German Polar and Marine Research Institute consider the Pirie Plateau to be a piece of the ancient continent Gondwana, which affects ice regime of Antarctica, thermal regime of World ocean and Earth's climate.
The Pirie Plateau appears to be a top of a micro-continent and, together with Bruce-Discovery plateau, forms a large fragment of the ancient continent Gondwana. Long ago this hilly plateau was a part of the continental bridge between South America and West Antarctica. As South America moved northwards from Antarctica, the bridge slowly submerged in the sea, forming the cold West Wind Drift, one of the most powerful currents of the World ocean, which forms Earth's climate together with the Gulf Stream current.
The Pirie Plateau continues to submerge, thus forming Earth's climate via affecting the West Wind Drift's intensity and ice regime of Antarctica.

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