WFS

Formation of sedimentary layers of white clay, Tamilnadu, India

Fossil site for wood fossils, Tamilnadu, India

Fossil site in Kerala, India

Fossil wood park maintained by geological survey of India at Tamilnadu

Cretaceous fossil sites india

Fossils in rack:-Cyad

Fossils in rack:-echiniderms

Fossils in rack:-Rastellum sp

Pre-historic seabed, Cretaceous period

Old Bird, New World: Did the South American Hoatzins Originate in Europe?

January 23rd, 2014

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The oldest fossil discoveries from France show that hoatzins once existed in Europe.

Where did hoatzins come from? These unusual birds, only one species of which exists in South America today, originated in the Old World. Studies of the oldest known fossils of Hoatzin ancestors have now shown that these birds existed around 34 million years ago in Europe. Paleornithologists at the Senckenberg Gesellschaft für Naturforschung and Flinders University in Adelaide published their findings this week in the specialist journal Naturwissenschaften.

The Hoatzin (Opisthocomus hoazin) is also known as the Stinkbird or Canje Pheasant and today exists only in parts of South America. Its relationship among birds is as unclear as its evolutionary history. Until recently, South America was considered to be the area of origin of these birds. Then, however, fossils from Africa were described, and new discoveries from Africa and Europe now prove conclusively that hoatzins reached South America from the Old World. A study published in January 2014 in the ornithological journal “The Auk” provided the very first evidence of largely modern Hoatzins from the Miocene (15 million years ago) in Africa.

Protoazin parisiensis and Opisthocomus hoazin. (Credit: © Senckenberg)

The oldest fossils attributed to hoatzins were found more than 100 years ago near Paris. But only now have paleornithologists been able to show that these remains belong to ancestors of the modern Hoatzin. The fossils belong to a newly described species, Protoazin parisiensis (“proto-Hoatzin from Paris”). The re-interpretation of these bones indicates that hoatzins lived in Europe as early as the late Eocene, i.e. around 34 million years ago.

“This supports the theory that hoatzins originated in the Old World,” says Dr Gerald Mayr of the Senckenberg Research Institute in Frankfurt. In the opinion of Dr Vanesa De Pietri of Flinders University in Australia, it is “a further impressive example that the South American avian fauna contains numerous relicts that were once much more widespread.”

Most notably, Hoatzins appear to have become extinct in Europe much earlier than in Africa, where the latest fossils were dated as of Miocene age (15 million years ago) and are thus only around half as old. The disappearance of these birds might be connected to a period when numerous new animal species migrated from Asia to Europe during the so-called “Grande Coupure” around 34 million years ago. These included tree-dwelling carnivorous mammals who may have posed a threat to hoatzin nestlings, which are raised in open nests. Because hoatzins can fly short distances only, the adult birds are also easy prey. In Africa, by contrast, similar tree-dwelling carnivorous mammals are shown to have existed much later.

Digestion specialist and climbing artist

The present-day Hoatzin exhibits a special mode of digestion. These herbivores pre-digest their food in this crop before further processing in the stomach and intestines. Similar to the rumen of a cow — a digestive knack that has not been mastered by any other bird. Skeletal features show that Old World hoatzins already had a large crop. Another special feature of the Hoatzin are the claws on the wings of the chicks, which enable the hatchlings to climb trees.

Ancient marine fossil found

January 22nd, 2014

Riffin

A unique fossil found at the tip of the South Island has been recognised as a 20-million-year-old marine ancestor.

The fossil, discovered near Cape Farewell, was collected and analysed by geologists at the University of Otago.

They described it as a close relation to the ancestors of modern dolphins and toothed whales.

Professor Ewan Fordyce has dubbed the fossil Papahu taitapu.

Professor Ewan Fordyce and his PhD student, Dr Gabriel Aguirre, dubbed the fossil Papahu taitapu, and said it was the first of its kind ever found. This made it a significant addition to the fossil record of dolphins from the southern hemisphere.

Papahu is estimated to have lived between 19 million and 20 million years ago, making it one of the few dolphins dating to the start of the Miocene epoch.

“New Zealand was substantially under water back then,” Fordyce said.

“There were wide shallow seaways. We know also that the climate was fairly warm, a lot warmer than today, with water temperatures down south about 18 degrees [Celsius] or warmer – good for swimming!”

Judging from the size of Papahu’s skull, the dolphin was about 2 metres long – roughly the size of a common dolphin – and likely had “many simple conical teeth”, he said.

Features of the skull showed that it was distinct from all previously reported fossils, which was why the dolphin could be formally named as a new form.

“When we compared Papahu with both modern and fossil dolphins we found that it belongs in a diverse and structurally variable group of ancient dolphins that evolved and spread worldwide 19 million to 35 million years ago,” Fordyce said.

“All of those ancient dolphins including Papahu and others, such as shark-toothed dolphins, are now extinct.

“They have been replaced by the modern dolphins and toothed whales, which diversified within the last 19 million years.”

It was not clear why Papahu and other ancient dolphins went extinct.

source: © Fairfax NZ News

First Dinosaurs Identified from Saudi Arabia

January 20th, 2014

Riffin

Dinosaur fossils are exceptionally rare in the Arabian Peninsula. An international team of scientists from Uppsala University, Museum Victoria, Monash University, and the Saudi Geological Survey have now uncovered the first record of dinosaurs from Saudi Arabia.

What is now dry desert was once a beach littered with the bones and teeth of ancient marine reptiles and dinosaurs.

A string of vertebrae from the tail of a huge “Brontosaurus-like” sauropod, together with some shed teeth from a carnivorous theropod represent the first formally identified dinosaur fossils from Saudi Arabia, and were found in the north-western part of the Kingdom along the coast of the Red Sea.

The remains were discovered during excavations conducted by a team of scientists working under the auspices of the Saudi Geological Survey, Jeddah.

Adaffa Theropod Tooth: This isolated tooth evidences the first identifiable carnivorous theropod dinosaur from the Arabian Peninsula. Abelisaurids like this specimen have been found in the ancient Gondwanan landmasses of North Africa, Madagascar and South America. (Credit: Photo by Maxim Leonov (Palaeontological Institute, Moscow)

The dinosaur finds were recently published in the scientific journal PLOS ONE and jointly authored by participating researchers from Sweden, Australia and Saudi Arabia.

“Dinosaur fossils are exceptionally rare in the Arabian Peninsula, with only a handful of highly fragmented bones documented this far” says Dr Benjamin Kear, based at Uppsala University in Sweden and lead author of the study.

“This discovery is important not only because of where the remains were found, but also because of the fact that we can actually identify them. Indeed, these are the first taxonomically recognizable dinosaurs reported from the Arabian Peninsula” Dr Kear continues.

“Dinosaur remains from the Arabian Peninsula and the area east of the Mediterranean Sea are exceedingly rare because sedimentary rocks deposited in streams and rivers during the Age of Dinosaurs are rare, particularly in Saudi Arabia itself” says Dr Tom Rich from Museum Victoria in Australia.

When these dinosaurs were alive, the Arabian landmass was largely underwater and formed the north-western coastal margin of the African continent.

“The hardest fossil to find is the first one. Knowing that they occur in a particular area and the circumstances under which they do, makes finding more fossils significantly less difficult” says Dr Rich.

The teeth and bones are approximately 72 million years old.

Two types of dinosaur were described from the assemblage, a bipedal meat-eating abelisaurid distantly related to Tyrannosaurus but only about six metres long, and a plant-eating titanosaur perhaps up to 20 metres in length.

Similar dinosaurs have been found in North Africa, Madagascar and as far away as South America.

Fossil Bird Eggshell Provides Source of Ancient DNA

January 19th, 2014

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In a world first an international team of researchers, led by Dr Michael Bunce of Murdoch University, have successfully isolated ancient DNA from fossil eggshell remains of extinct birds.

“We were really surprised to discover that ancient DNA is well-preserved in fossil eggshells, particularly the heaviest bird to have existed the elephant bird called Aepyornis, which is now extinct,” said Murdoch doctoral student Charlotte Oskam, who undertook the research.

“Researchers have tried unsuccessfully to isolate DNA from fossil eggshell for years — it just turned out that they were using a method designed for bone that was not suitable for fossil eggshell.”

In a world first an international team of researchers, led by Dr Michael Bunce of Murdoch University, have successfully isolated ancient DNA from fossil eggshell remains of extinct birds. (Credit: Image courtesy of Murdoch University)

The new study published this week in the scientific journal Proceedings of the Royal Society B describes how DNA up to 19,000 years old is an excellent source of ancient DNA especially in warmer climates such as Australia.

Fossil eggshells are frequently recovered from deposits across the globe and have been extensively used as a tool for radiocarbon dating and as a proxy to study past environments.

Now, thanks to this new study, a DNA profile will be added to these datasets.

The ancient DNA research team now plans to study eggshell from a number of archaeological sites in New Zealand to investigate how humans interacted with another giant bird, the moa, which went extinct nearly 600 years ago due to hunting pressures.

Supervolcanic Ash Can Turn to Lava Miles from Eruption

January 17th, 2014

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Supervolcanoes, such as the one sitting dormant under Yellowstone National Park, are capable of producing eruptions thousands of times more powerful than normal volcanic eruptions. While they only happen every several thousand years, these eruptions have the potential to kill millions of people and animals due to the massive amount of heat and ash they release into the atmosphere. Now, researchers at the University of Missouri have shown that the ash produced by supervolcanoes can be so hot that it has the ability to turn back into lava once it hits the ground tens of miles away from the original eruption.

Following a volcanic eruption, lava typically flows directly from the site of the eruption until it cools enough that it hardens in place. However, researchers found evidence of an ancient lava flow tens of miles away from a supervolcano eruption near Yellowstone that occurred around 8 million years ago. Previously, Graham Andrews, an assistant professor at California State University Bakersfield, found that this lava flow was made of ash ejected during the eruption. Following Andrew’s discovery, Alan Whittington, an associate professor in the University of Missouri department of geological sciences in the College of Arts and Science, along with lead author Genevieve Robert and Jiyang Ye, both doctoral students in the geological sciences department, determined how this was possible.

Evidence of flowing lava hardened into rock found in Idaho several miles away from the site of an 8 million year old supervolcano eruption at Yellowstone. (Credit: Graham Andrews, assistant professor at California State University Bakersfield.)

“During a supervolcano eruption, pyroclastic flows, which are giant clouds of very hot ash and rock, travel away from the volcano at typically a hundred miles an hour,” Robert said. “We determined the ash must have been exceptionally hot so that it could actually turn into lava and flow before it eventually cooled.”

Because the ash should have cooled too much in the air to turn into lava right as it landed, the researchers believe the phenomenon was made possible by a process known as “viscous heating.” Viscosity is the degree to which a liquid resists flow. The higher the viscosity, the less the substance can flow. For example, water has a very low viscosity, so it flows very easily, while molasses has a higher viscosity and flows much slower. Whittington likens the process of viscous heating to stirring a pot of molasses.

“It is very hard to stir a pot of molasses and you have to use a lot of energy and strength to move your spoon around the pot,” Whittington said. “However, once you get the pot stirring, the energy you are using to move the spoon is transferred into the molasses, which actually heats up a little bit. This is viscous heating. So when you think about how fast the hot ash is traveling after a massive supervolcano eruption, once it hits the ground that energy is turned into heat, much like the energy from the spoon heating up the molasses. This extra heat created by viscous heating is enough to cause the ash to weld together and actually begin flowing as lava.”

The volcanic ash from this eruption has to be at least 1,500 degrees Fahrenheit to turn into lava; however, since the ash should have lost some of that heat in the air, the researchers believe viscous heating accounted for 200 to 400 degrees Fahrenheit of additional heating to turn the ash into lava.

Robert, Andrews, Ye, and Whittington’s paper was published in Geology. The National Science Foundation funded this research through a CAREER award to Whittington.

How Could Dinosaurs Weigh Up to 80 Tons? New Research On Sauropod Gigantism

January 16th, 2014

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Sauropods, the largest land animals in Earth’s history, are still mightily puzzling the scientists. These plant-eating dinosaurs with their long necks and small heads could reach a height of 10 meters or more and dominated all other land vertebrates in terms of size. They could weigh up to 80 tons, more than any other known land vertebrate. One question that has been intensely debated is how these giants of the animal kingdom regulated their own body temperature.

According to the calculations of the Mainz-based ecologist, the body temperature of these animals did not increase with body weight. Her estimates indicate that sauropods may have had an average body temperature of some 28 degrees Celsius. The upper limit for the body temperature that can be tolerated by vertebrate species living today is 45 degrees Celsius. The body temperatures that Griebeler postulates for the sauropods are thus well below those of today’s endothermic vertebrates but consistent with those of ectothermic monitor lizards. Her calculations of sauropod body temperature take into account the relationship between the maximum rate of growth and the basal metabolic rate of an animal, whereby the latter is largely determined by body temperature.

Griebeler’s work is part of a collection that brings together the results of recent research into sauropod gigantism. The gigantism of these vertebrates, unique in the history of Earth, raises many questions, such as why no other land creatures have ever achieved this size and what their bauplan, physiology, and life cycle would have been like. The collection put together by the leading open access journal PLOS ONE consists of 14 contributions from the fields of ecology, morphology, animal nutrition, and paleontology that all address the fundamental question of how the sauropods managed to become so extraordinarily massive.

Egg containing a titanosaur embryo, on display as part of a special exhibition at the Senckenberg Natural History Museum, Frankfurt am Main. This fossilized egg was discovered in Neuquén province, Argentina, and has an approximate diameter of 15 centimeters. (Credit: copyright Eva Maria Griebeler)

“We are pleased that this new research is freely accessible not only to other scientists, but also to sauropod fans,” said PD Dr. Eva Maria Griebeler. She and Dr. Jan Werner are members of the research group “Biology of the Sauropod Dinosaurs: The Evolution of Gigantism (FOR 533),” funded by the German Research Foundation (DFG). The collection was initiated as a result of a related international conference on this subject. Both scientists from the Ecology division at the Institute of Zoology at Mainz University have been working for more than six years within this research group. They have written three of the 14 contributions in the collection.

In one article, Jan Werner and his colleague Koen Stein of the University of Bonn describe a new method of determining the density of bone tissue and juxtapose sauropod data and results extrapolated for comparable endothermic mammals. Although the bone structure and the density of certain tissues of sauropods were similar to those of today’s mammals, the results do not conclusively demonstrate that sauropods were also endothermic animals. Other functional aspects, such as similar weight-bearing stresses, could have resulted in the development of convergent forms of bone tissue.

Another article looks at the reproductive biology of sauropods. Here Werner and Griebeler discuss the hypothesis that a high rate of reproduction contributed to the gigantism of the large dinosaurs. They discovered that the reproductive pattern of most dinosaurs was similar to that of modern reptiles and birds. The reproductive pattern of theropods, i.e., ancestors of the modern birds, turned out to be comparable with that of birds, prosauropods, and sauropods rather than reptiles. However, contrary to the assumptions of previous studies, the calculations of the Mainz scientists did not corroborate the hypothesis that the large dinosaurs would have laid a particularly large number of eggs. In terms of total eggs produced annually, this number could not have exceeded 200 to 400 eggs for a sauropod weighing 75 tons. Today’s large sea turtles are known to lay clutches in this range.

Supervolcano Triggers Recreated in X-Ray Laboratory

January 15th, 2014

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Scientists have reproduced the conditions inside the magma chamber of a supervolcano to understand what it takes to trigger its explosion. These rare events represent the biggest natural catastrophes on Earth except for the impact of giant meteorites. Using synchrotron X-rays, the scientists established that supervolcano eruptions may occur spontaneously, driven only by magma pressure without the need for an external trigger. The results are published in Nature Geosciences.

The team was led by Wim Malfait and Carmen Sanchez-Valle of ETH Zurich (Switzerland) and comprised scientists from the Paul Scherrer Institute in Villigen (Switzerland), Okayama University (Japan), the Laboratory of Geology of CNRS, Université Lyon 1 and ENS Lyon (France) and the European Synchrotron (ESRF) in Grenoble (France).

This artist’s impression depicts the magma chamber of a supervolcano with partially molten magma at the top. The pressure from the buoyancy is sufficient to initiate cracks in the Earth’s crust in which the magma can penetrate. (Credit: ESRF/Nigel Hawtin)

A well-known supervolcano eruption occurred 600,000 years ago in Wyoming in the United States, creating a huge crater called a caldera, in the centre of what today is Yellowstone National Park. When the volcano exploded, it ejected more than 1000 km³ of ash and lava into the atmosphere, 100 times more than Mt Pinatubo in the Philippines did in 1992. Big volcanic eruptions have a major impact on the global climate. The Mt Pinatubo eruption decreased the global temperature by 0.4 degrees Celsius for a few months. The predictions for a super volcano are a fall in temperatures by 10 degrees Celsius for 10 years.

According to a 2005 report by the Geological Society of London, “Even science fiction cannot produce a credible mechanism for averting a super-eruption. We can, however, work to better understand the mechanisms involved in super-eruptions, with the goal of being able to predict them ahead of time and provide a warning for society. Preparedness is the key to mitigation of the disastrous effects of a super-eruption.”

The mechanisms that trigger supervolcano eruptions have remained elusive to date. The main reason is that the processes inside a supervolcano are different from those in conventional volcanoes like Mt. Pinatubo which are better understood. A supervolcano possesses a much larger magma chamber and it is always located in an area where the heat flow from the interior of Earth to the surface is very high. As a consequence, the magma chamber is very large and hot but also plastic: its shape changes as a function of the pressure when it gradually fills with hot magma. This plasticity allows the pressure to dissipate more efficiently than in a normal volcano whose magma chamber is more rigid. Supervolcanoes therefore do not erupt very often.

So what changes in the lead up to an eruption? Wim Malfait explains: “The driving force is an additional pressure which is caused by the different densities of solid rock and liquid magma. It is comparable to a football filled with air under water, which is forced upwards by the denser water around it.” Whether this additional pressure alone could eventually become sufficiently high to crack Earth’s crust, leading to a violent eruption, or whether an external energy source like an Earthquake is required has only now been answered.

Whilst it is virtually impossible to drill a hole into the magma chamber of a supervolcano given the depth at which these chambers are buried, one can simulate these extreme conditions in the laboratory. “The synchrotron X-rays at the ESRF can then be used to probe the state — liquid or solid — and the change in density when magma crystallises into rock” says Mohamed Mezouar, scientist at the ESRF and member of the team. Jean-Philippe Perrillat from the Laboratory of Geology of CNRS, Université Lyon 1 and ENS Lyon adds: “Temperatures of up to 1700 degrees and pressures of up to 36,000 atmospheres can be reached inside the so-called Paris-Edinburgh press, where speck-sized rock samples are placed between the tips of two tungsten carbide anvils and then heated with a resistive furnace. This special set-up was used to accurately determine the density of the liquid magma over a wide range of pressures and temperatures.”

Magma often includes water, which as vapour adds additional pressure. The scientists also determined magma densities as a function of water content.

The results of their measurements showed that the pressure resulting from the differences in density between solid and liquid magma rock is sufficient in itself to crack more than ten kilometres of Earth’s crust above the magma chamber. Carmen Sanchez-Valle concludes: “Our research has shown that the pressure is actually large enough for Earth’s crust to break. The magma penetrating into the cracks will eventually reach Earth’s surface, even in the absence of water or carbon dioxide bubbles in the magma. As it rises to the surface, the magma will expand violently, which is the well known origin of a volcanic explosion.”

Ref: Wim J. Malfait, Rita Seifert, Sylvain Petitgirard, Jean-Philippe Perrillat, Mohamed Mezouar, Tsutomu Ota, Eizo Nakamura, Philippe Lerch, Carmen Sanchez-Valle. Supervolcano eruptions driven by melt buoyancy in large silicic magma chambers. Nature Geoscience, 2014; DOI: 10.1038/ngeo2042

Discovery of New Tiktaalik Roseae Fossils Reveals Key Link in Evolution of Hind Limbs

January 14th, 2014

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The discovery of well-preserved pelves and a partial pelvic fin from Tiktaalik roseae, a 375 million-year-old transitional species between fish and the first legged animals, reveals that the evolution of hind legs actually began as enhanced hind fins. This challenges existing theory that large, mobile hind appendages were developed only after vertebrates transitioned to land. The fossils are described by scientists in the Proceedings of the National Academy of Sciences, online on Jan. 13.

“Previous theories, based on the best available data, propose that a shift occurred from ‘front-wheel drive’ locomotion in fish to more of a ‘four-wheel drive’ in tetrapods,” said Neil Shubin, PhD, Robert R. Bensley Distinguished Service Professor of Anatomy at the University of Chicago and corresponding author of the study, which marks his inaugural article as a member of the National Academy of Sciences. “But it looks like this shift actually began to happen in fish, not in limbed animals.”

Discovered in 2004 by Shubin and co-authors Edward Daeschler, PhD, Associate Curator of Vertebrate Zoology at the Academy of Natural Sciences of Drexel University, and the late Farish A. Jenkins, Jr., PhD, of Harvard University, Tiktaalik roseae represents the best-known transitional species between fish and land-dwelling tetrapods.

This is an updated illustration of Tiktaalik roseae in its natural environment. (Credit: University of Chicago, Neil Shubin)

A lobe-finned fish with a broad flat head and sharp teeth, Tiktaalik looked like a cross between a fish and a crocodile, growing up to a length of 9 feet as it hunted in shallow freshwater environments. It had gills, scales and fins, but also had tetrapod-like features such as a mobile neck, robust ribcage and primitive lungs. In particular, its large forefins had shoulders, elbows and partial wrists, which allowed it to support itself on ground.

However, only specimen blocks containing the front portion of Tiktaalik have been described thus far. As the researchers investigated additional blocks recovered from their original and subsequent expeditions to the dig site in northern Canada, they discovered the rear portion of Tiktaalik, which contained the pelves as well as partial pelvic fin material. The fossils included the complete pelvis of the original ‘type’ specimen, making a direct comparison of the front and rear appendages of a single animal possible.

The scientists were immediately struck by the pelvis, which was comparable to those of some early tetrapods. The Tiktaalik pelvic girdle was nearly identical in size to its shoulder girdle, a tetrapod-like characteristic. It possessed a prominent ball and socket hip joint, which connected to a highly mobile femur that could extend beneath the body. Crests on the hip for muscle attachment indicated strength and advanced fin function. And although no femur bone was found, pelvic fin material, including long fin rays, indicated the hind fin was at least as long and as complex as its forefin.

“This is an amazing pelvis, particularly the hip socket, which is very different from anything that we knew of in the lineage leading up to limbed vertebrates,” Daeschler said. “Tiktaalik was a combination of primitive and advanced features. Here, not only were the features distinct, but they suggest an advanced function. They appear to have used the fin in a way that’s more suggestive of the way a limb gets used.”

Tiktaalik pelves were still clearly fish-like, with primitive features such as an undivided skeletal configuration, as opposed to the three-part pelvic girdle of early tetrapods. However, the expanded size, mobility and robusticity of the pelvic girdle, hip joint and fin of Tiktaalik made a wide range of motor behaviors possible.

“It’s reasonable to suppose with those big fin rays that Tiktaalik used its hind fins to swim like a paddle,” Shubin said. “But it’s possible it could walk with them as well. African lungfish living today have similarly large pelves, and we showed in 2011 that they walk underwater on the bottom.”

“Regardless of the gait Tiktaalik used, it’s clear that the emphasis on hind appendages and pelvic-propelled locomotion is a trend that began in fish, and was later exaggerated during the origin of tetrapods,” Shubin said.

Shubin will be hosting a three-part TV series based on his book “Your Inner Fish,” on PBS in April 2014, tracing the origins of the human body through the DNA of living animals and the legacies of now-extinct, but biologically important species such as Tiktaalik roseae.

Courtesy: Science daily

Taking the ‘Pulse’ of Volcanoes Using Satellite Images

January 13th, 2014

Riffin

A new study by scientists at the University of Miami (UM) Rosenstiel School of Marine & Atmospheric Science uses Interferometric Synthetic Aperture Radar (InSAR) data to investigate deformation prior to the eruption of active volcanoes in Indonesia’s west Sunda arc. Led by geophysicist Estelle Chaussard and UM Professor Falk Amelung, the study uncovered evidence that several volcanoes did in fact ‘inflate’ prior to eruptions due to the rise of magma. The fact that such deformation could be detected by satellite is a major step forward in volcanology; it is the first unambiguous evidence that remotely detected ground deformation could help to forecast eruptions at volcanoes.

“Surveying entire volcanic regions using satellite data is of primary importance to the detection of ground deformation prior to the onset of eruptions. If volcanic inflation is observed, it can help us to predict where the next eruption may occur. Moreover, in regions like Indonesia, where volcanoes are prevalent and pose a threat to millions of people, and where ground-based monitoring is sparse, remote sensing via satellite could become a major forecasting tool,” said Chaussard.

Analyzing more than 800 InSAR images from the Japanese Space Exploration Agency’s ALOS satellite, the team surveyed 79 volcanoes in Indonesia between 2006 and 2009. They detected deformation at six volcanic centers, three of which erupted after the observation period, confirming that inflation is a common precursor of volcanic eruptions at west Sunda volcanoes.

This image shows averaged 2006-2009 ground velocity map of the west Sunda volcanic region from the Japanese Space Agency’s ALOS satellite. Positive velocity (red colors) represents movement towards the satellite (e.g. uplift) and negative velocity (blue colors) movement away from the satellite (e.g. subsidence). Locations of volcanoes are marked by black triangles, historically active volcanoes by red triangles. Insets show six inflating volcanoes. (Credit: Estelle Chaussard, University of Miami)

“The notion of detecting deformation prior to a volcanic eruption has been around for a while,” said Amelung, who has been studying active volcanoes for 15 years. “Because this region is so volcanically active, our use of InSAR has been very successful. We now have a tool that can tell us where eruptions are more likely to occur.”

The team will now study other parts of Indonesia and then in the Philippines, also prone to volcanic activity. They will use data from the Japanese Space Agency’s ALOS-2 which will be launched next year.

“The monitoring of changes to the Earth’s surface helps us to better predict the onset of volcanic activity, which can have devastating impacts on human life,” said Amelung. “Like with earthquakes and tsunamis, however, we cannot predict activity with certainty, but we hope that new tools like satellite remote sensing will help us to gather critical information in near real-time so we can anticipate the risk of eruptions and deploy resources in a timely manner.”

This study also reveals that there are regional trends in depths of magma storage. Indonesian volcanoes have magma reservoirs at shallow depths probably due to the tectonic setting of the region, which account for the way the region is deforming. If a volcanic chamber is located close to the surface it is usually associated with a higher risk for significant eruption, thus these observations play a major role in volcanic hazard assessment.

Fossil Pigments Reveal the Colors of Ancient Sea Monsters

January 12th, 2014

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During the Age of the dinosaurs, huge reptiles, such as mosasaurs and ichthyosaurs, ruled the seas. Previously, scientists could only guess what colours these spectacular animals had; however, pigment preserved in fossilised skin has now been analysed at SP Technical Research Institute of Sweden and MAX IV Laboratory, Lund University, Sweden. The unique soft tissue remains were obtained from a 55 million-year-old leatherback turtle, an 85 million-year-old mosasaur and a 196-190 million-year-old ichthyosaur. This is the first time that the colour scheme of any extinct marine animal has been revealed.

Preserved pigment in fossilized skin from a leatherback turtle, a mosasaur and an ichthyosaur suggests that these animals were, at least partially, dark-colored in life — an example of convergent evolution. Note that the leatherback turtle and mosasaur have a dark back and light belly (a color scheme also known as countershading), whereas the ichthyosaur, similar to the modern deep-diving sperm whale, is uniformly dark-colored. (Credit: Illustration by Stefan Sølberg)

“This is fantastic! When I started studying at Lund University in 1993, the film Jurassic Park had just been released, and that was one of the main reasons why I got interested in biology and palaeontology. Then, 20 years ago, it was unthinkable that we would ever find biological remains from animals that have been extinct for many millions of years, but now we are there and I am proud to be a part of it,” said Johan Lindgren about the discovery of the ancient pigment molecules.

Johan Lindgren is a scientist at Lund University in Sweden, and he is the leader of the international research team that has studied the fossils. Together with colleagues from Denmark, England and the USA, he now presents the results of their study in the scientific journal Nature. The most sensational aspect of the investigation is that it can now be established that these ancient marine reptiles were, at least partially, dark-coloured in life, something that probably contributed to more efficient thermoregulation, as well as providing means for camouflage and protection against harmful UV radiation.

The analysed fossils are composed of skeletal remains, in addition to dark skin patches containing masses of micrometre-sized, oblate bodies. These microbodies were previously interpreted to be the fossilised remains of those bacteria that once contributed to the decomposition and degradation of the carcasses. However, by studying the chemical content of the soft tissues, Lindgren and his colleagues are now able to show that they are in fact remnants of the animals’ own colours, and that the micrometre-sized bodies are fossilised melanosomes, or pigment-containing cellular organelles.

“Our results really are amazing. The pigment melanin is almost unbelievably stable. Our discovery enables us to make a journey through time and to revisit these ancient reptiles using their own biomolecules. Now, we can finally use sophisticated molecular and imaging techniques to learn what these animals looked like and how they lived,” said Per Uvdal, one of the co-authors of the study, and who works at the MAX IV Laboratory.

Mosasaurs (98-66 million years ago) are giant marine lizards that could reach 15 metres in body length, whereas ichthyosaurs (250-94 million years ago) could become even larger. Both ichthyosaurs and mosasaurs died out during the Cretaceous Period, but leatherback turtles are still around today. A conspicuous feature of the living leatherback turtle, Dermochelys, is that it has an almost entirely black back, which probably contributes to its worldwide distribution. The ability of leatherback turtles to survive in cold climates has mainly been attributed to their huge size, but it has also been shown that these animals bask at the sea surface during daylight hours. The black colour enables them to heat up faster and to reach higher body temperatures than had they instead been lightly coloured.

“The fossil leatherback turtle probably had a similar colour scheme and lifestyle as does Dermochelys. Similarly, mosasaurs and ichthyosaurs, which also had worldwide distributions, may have used their darkly coloured skin to heat up quickly between dives,” said Johan Lindgren.

If their interpretations are correct, then at least some ichthyosaurs were uniformly dark-coloured in life, unlike most living marine animals. However, the modern deep-diving sperm whale has a similar colour scheme, perhaps as camouflage in a world without light, or as UV protection, given that these animals spend extended periods of time at or near the sea surface in between dives. The ichthyosaurs are also believed to have been deep-divers, and if their colours were similar to those of the living sperm whale, then this would also suggest a similar lifestyle, according to Lindgren.