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

New Way To Monitor Faults May Help Predict Earthquakes

December 6th, 2013

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Scientists at the Carnegie Institution have found a way to monitor the strength of geologic faults deep in the Earth. This finding could prove to be a boon for earthquake prediction by pinpointing those faults that are likely to fail and produce earthquakes. Until now, scientists had no method for detecting changes in fault strength, which is not measureable at the Earth’s surface.

Paul Silver* and Taka’aki Taira of the Carnegie Institution’s Department of Terrestrial Magnetism, with Fenglin Niu of Rice University and Robert Nadeau of the University of California, Berkeley, used highly sensitive seismometers to detect subtle changes in earthquake waves that travel through the San Andreas Fault zone near Parkfield, California, over a period of 20 years. The changes in the waves indicate weakening of the fault and correspond to periods of increased rates of small earthquakes along the fault.

“Fault strength is a fundamental property of seismic zones,” says Taira, now at the University of California, Berkeley. “Earthquakes are caused when a fault fails, either because of the build-up of stress or because of a weakening of the fault. Changes in fault strength are much harder to measure than changes in stress, especially for faults deep in the crust. Our result opens up exciting possibilities for monitoring seismic risk and understanding the causes of earthquakes.”

The section of the San Andreas Fault near Parkfield, sometimes called the “Earthquake Capital of the World,” has been intensively studied by seismologists and is home to a sophisticated array of borehole seismometers called the High-Resolution Seismic Network and other geophysical instruments. Because the area experiences numerous repeated small earthquakes, it is a natural laboratory for studying the physics of earthquakes.

Seismograms from small earthquakes revealed that within the fault zone there were areas of fluid-filled fractures. What caught the researchers’ attention was that these areas shifted slightly from time to time. The repeating earthquakes also became smaller and more frequent during these intervals – an indication of a weakened fault.

“Movement of the fluid in these fractures lubricates the fault zone and thereby weakens the fault,” says Niu. “The total displacement of the fluids is only about 10 meters at a depth of about three kilometers, so it takes very sensitive seismometers to detect the changes, such as we have at Parkfield.”

What caused the fluids to shift? Intriguingly, the researchers noticed that on two occasions the shifts came after the fault zone was disturbed by seismic waves from large, distant earthquakes, such as the 2004 Sumatra-Andaman Earthquake. Pressure from these waves may have been enough to cause the fluids to flow. “So it is possible that the strength of faults and earthquake risk is affected by seismic events on the other side of the world,” says Niu.

The paper is published in the October 1 edition of Nature.

*Paul Silver died tragically in an automobile accident in August.

Niassodon mfumukasi fossil Reveals New Data On Ancient Mammal Relatives

December 5th, 2013

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In the remote province of Niassa, Mozambique, a new species and genus of fossil vertebrate was found. The species is a distant relative of living mammals and is approximately 256 million years old. This new species belongs to a group of animals called synapsids. Synapsida includes a number of extinct lineages that dominated the communities on land in the Late Permian (260-252 million years ago), as well as living mammals and their direct ancestors.

A team of paleontologists from nine institutions, including Kenneth Angielczyk, associate curator of paleomammology at Chicago’s Field Museum, described the anatomy of Niassodon in the scientific journal PLoS ONE. The fossil was named Niassodon mfumukasi, which means in the local language (Chiyao): the queen of Lake Niassa. The name is a tribute to the Yao matriarchal society, to the women of Mozambique and to the beauty of Lake Niassa.

Preserved skeletal elements of Niassodon mfumukasi (ML1620) imposed on a Pristerodon silhouette. Skeletal parts repositioned are in dark grey. Skeletal parts mirrored from the other side are in light grey. Skeletal parts in the original position are in intermediate grey. (Credit: Rui Castanhinha et al. Bringing Dicynodonts Back to Life: Paleobiology and Anatomy of a New Emydopoid Genus from the Upper Permian of Mozambique. PLoS ONE, 2013; 8 (12): e80974 DOI: 10.1371/journal.pone.0080974)

The research was conducted under the auspices of Projecto PalNiassa, an international, multidisciplinary scientific collaboration that includes more than two dozen scientists from three different continents. The goal of the project is to find, study, and preserve the paleontological heritage of Mozambique.

Niassodon mfumukasi is the first new genus (and species) of a fossil vertebrate from Mozambique, and its holotype (name-bearing specimen) is a rare example of a basal synapsid that preserves the skull and much of the skeleton together.

By using micro-computed tomography it was possible to reconstruct digitally not only the bones of Niassodon but also to build a virtual model of its brain. This reveals new information on the brain anatomy of early synapsids, which is important for understanding the evolution of many features of the mammalian brain. The reconstruction of the brain and inner ear anatomy developed for Niassodon is the most detailed presented to date for an early synapsid. Using the digital data acquired in the tomographies, it was possible to isolate all individual bones preserved which allowed the researchers to create a new topological color code, codified mathematically, for the cranial bones. This code will allow the researchers to standardize the colors used in similar digital model built for other animals. The fossil can be visited in the Lourinhã Museum (Portugal), but soon will return to Mozambique, where it will become part of the collections of the National Museum of Geology in Maputo.

The specimen was collected during fieldwork in 2009 with the support of National Museum of Geology (Maputo) and was prepared at the Lourinhã Museum (Portugal), Instituto Gulbenkian de Ciência (Oeiras, Portugal) and Southern Methodist University (Dallas); the 3D tomography was performed in DESY-HZG (Hamburg, Germany). This project was sponsored by Fundação Calouste Gulbenkian, the National Geographic Society, and TAP Portugal.

What Drives Aftershocks?

December 3rd, 2013

Riffin

On 27 February 2010 an earthquake of magnitude 8.8 struck South-Central Chile near the town of Maule. The main shock displaced the subduction interface by up to 16 meters. Like usually after strong earthquakes a series of aftershocks occurred in the region with decreasing size over the next months. A surprising result came from an afterslip study: Up to 2 meters additional slip occurred along the plate interface within 420 days only, in a pulse like fashion and without associated seismicity. An international research group lead by GFZ analysed the main shock as well as the following postseismic phase with a dense network of instruments including more than 60 high-resolution GPS stations.

The aftershocks and the now found “silent” afterslip are key to understand the processes occurring after strong earthquakes. The GPS data in combination with seismological data allowed for the first time a comparative analysis: Are aftershocks triggered solely by stress transfer from the main shock or are additional mechanisms active? “Our results suggest, that the classic view of the stress relaxation due to aftershocks are too simple” says Jonathan Bedford from GFZ to the new observation: “Areas with large stress transfer do not correlate with aftershocks in all magnitude classes as hitherto assumed and stress shadows show surprisingly high seismic activity.”

Setting up a Creepmeter Station in Southern Central Chile. (Credit: GFZ)

A conclusion is that local processes which are not detectable at the surface by GPS monitoring along the plate interface have a significant effect on the local stress field. Pressurized fluids in the crust and mantle could be the agent here. As suspected previously, the main and aftershocks might have generated permeabilities in the source region which are explored by hydrous fluids. This effects the local stress field triggering aftershocks rather independently from the large scale, main shock induced stress transfer. The present study provides evidences for such a mechanism. Volume (3D) seismic tomography which is sensitive to fluid pressure changes in combination with GPS monitoring will allow to better monitor the evolution of such processes.

The main shock was due to a rupture of the interface between the Nasca and the South American plates. Aftershocks are associated with hazards as they can be of similar size as the main shock and, in contrast to the latter, much shallower in the crust.

Western Ghats: life line of india need world attention for protection

December 2nd, 2013

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The Western Ghats or the Sahyādri constitute a mountain range along the western side of India. It is a UNESCO World Heritage Site and is one of the eight “hottest hotspots” of biological diversity in the world. It is sometimes called the Great Escarpment of India. The range runs north to south along the western edge of the Deccan Plateau, and separates the plateau from a narrow coastal plain, called Konkan, along the Arabian Sea. A total of thirty nine properties including national parks, wildlife sanctuaries and reserve forests were designated as world heritage sites – twenty in Kerala, ten in Karnataka, five in Tamil Nadu and four in Maharashtra.

The range starts near the border of Gujarat and Maharashtra, south of the Tapti river, and runs approximately 1,600 km (990 mi) through the states of Maharashtra, Goa, Karnataka, Tamil Nadu and Kerala ending at Kanyakumari, at the southern tip of India.

These hills cover 160,000 km² (62,000 sq mi) and form the catchment area for complex riverine drainage systems that drain almost 40% of India. The Western Ghats block rainfall to the Deccan Plateau. The average elevation is around 1,200 m (3,900 ft).

The area is one of the world’s ten “Hottest biodiversity hotspots” and has over 5000 species of flowering plants, 139 mammal species, 508 bird species and 179 amphibian species; it is likely that many undiscovered species live in the Western Ghats. At least 325 globally threatened species occur in the Western Ghats.

The Western Ghats lie roughly parallel
to the west coast of India

Annual rainfall along the Western Ghat region

Madhav Gadgil, chairman of the Western Ghats Ecology Expert Panel, has rolled up his sleeves and slammed the Kasturirangan report.

Kasturirangan report on Western Ghats replaced the pro-people and pro-nature attitude of the Western Ghats Ecology Expert Panel report with an autocratic approach in terms of development and ecological conservation, said Madhav Gadgil, chairman of the panel.

Mr. Kasturirangan, in his report, wondered how local communities can have a role in the economic decision-making process of the country. The report had kept vast stretches of Western Ghats in the category cultural landscapes, which include human settlements, out of the purview of ecologically sensitive areas. The sacred groves of Kerala, which are rich in biodiversity, would come under the category. If the Kasturirangan report is accepted, any builder could raze the sacred groves and construct structures there, he said.

The panel chairman was in the town to deliver a lecture on protection of Western Ghats. The event was organised by the Indian Association of Lawyers (High Court Unit).

Mr. Gadgil said the panel report was completely distorted to give the impression that it recommended to halt all economic activities.

The report suggested that the Grama Sabhas should decide on the Ecological Sensitivity of the respective areas. People should decide in which ecologically sensitive zone their area should come under. The prerogative for deciding whether their area was to be considered even as a sensitive area was left to the people. The recommendation of the panel regarding the ecologically sensitive zones was just an indicator to start the debate, he said.

Environment history of the world would tell one that no country the in the world had ever initiated action on its own for ecological conservation. It came from people’s initiative. The thrust of the panel report was that people should be allowed to exercise appropriate powers for conservation, he said.

Referring to the decision of the Plachimada Panchayat to cancel the license for Coca Cola factory functioning in their area, Mr. Gadgil said the Supreme Court had upheld the right of the local body to take such a decision. People at grassroots levels really care for environment health as it is directly linked to their lives. People at the grassroots should be empowered to make appropriate decisions, he said.

The panel even recommended that people should be incentivised for conservation efforts like shifting to organic farming, Mr. Gadgil said.

‘Cascade of events’ caused sudden explosion of animal life

December 1st, 2013

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The explosion of animal life on Earth around 520 million years ago was the result of a combination of interlinked factors rather than a single underlying cause, according to a new study.

Dozens of individual theories have been put forward over the past few decades for this rapid diversification of animal species in the early Cambrian period of geological time.

But a paper by Professor Paul Smith of Oxford University and Professor David Harper of Durham University suggests a more holistic approach is required to discover the reasons behind what has become known as the Cambrian Explosion.

Theories for the Cambrian Explosion fall into three main categories – geological, geochemical and biological – and most have been claimed as standalone processes that were the main cause of the explosion.

Whatever the cause, this major evolutionary event led to a wide range of biological innovation, including the origin of modern ecosystems, a rapid increase in animal diversity, the origin of skeletons and the first appearance of specialist modes of life such as burrowing and swimming.

Among the weird and wonderful creatures to emerge in the early Cambrian was Anomalocaris, the free-swimming, metre-long top predator of the time with a mouth composed of 32 overlapping plates that could constrict to crush prey. It is distantly related to modern arthropods, including crabs and lobsters.

Vertebrate animals also made their first appearance in the Cambrian Explosion, the distant ancestors of modern fish, reptiles, birds and mammals.

Professor Smith, Professor Harper and a team of scientists have spent four years working on data from a site in northernmost Greenland, facing the Arctic Ocean.

The site, at Siriuspasset, is located at 83°N, just 500 miles from the North Pole in a remote part of north Greenland. Although logistically very difficult to reach, Siriuspasset attracted the team because of the high quality of its fossil material and the insights it provides.

Professor Smith and Professor Harper’s findings are published in the latest edition of the journal Science.

Professor Smith, lead author of the report and Director of the Oxford University Museum of Natural History, said: ‘This is a period of time that has attracted a lot of attention because it is when animals appear very abruptly in the fossil record, and in great diversity. Out of this event came nearly all of the major groups of animals that we recognise today.

‘Because it is such a major biological event, it has attracted much opinion and speculation about its cause.’

Described by the researchers as a ‘cascade of events’, the interacting causes behind the explosion in animal life are likely to have begun with an early Cambrian sea level rise. This generated a large increase in the area of habitable seafloor, which in turn drove an increase in animal diversity. These early events then translate into the complex interaction of biological, geochemical and geological processes described in individual hypotheses.

Professor Harper, Professor of Palaeontology in the Department of Earth Sciences at Durham University, said: ‘The Cambrian Explosion is one of the most important events in the history of life on our planet, establishing animals as the most visible part of the planet’s marine ecosystems.

‘It would be naïve to think that any one cause ignited this phenomenal explosion of animal life. Rather, a chain reaction involving a number of biological and geological drivers kicked into gear, escalating the planet’s diversity during a relatively short interval of deep time.
‘The Cambrian Explosion set the scene for much of the subsequent marine life that built on cascading and nested feedback loops, linking the organisms and their environment, that first developed some 520 million years ago.’
Professor Smith said: ‘Work at the Siriuspasset site in north Greenland has cemented our thinking that it wasn’t a matter of saying one hypothesis is right and one is wrong. Rather than focusing on one single cause, we should be looking at the interaction of a number of different mechanisms.

‘Most of the hypotheses have at least a kernel of truth, but each is insufficient to have been the single cause of the Cambrian explosion. What we need to do now is focus on the sequence of interconnected events and the way they related to each other – the initial geological triggers that led to the geochemical effects, followed by a range of biological processes.’

For further information, contact Professor Paul Smith at paul.smith@oum.ox.ac.uk or on +44 (0)1865 272 956, or Professor David Harper at david.harper@durham.ac.uk or on +44 (0)191 334 7143.

Alternatively, or for images, contact Oxford University Press Office at press.office@admin.ox.ac.uk or on +44 (0)1865 280 528, or Durham University Media Relations Office at media.relations@durham.ac.uk or on +44 (0)191 334 6075.

Source: The paper ‘Causes of the Cambrian Explosion’ by M. Paul Smith and David A. T. Harper is published in Science, Vol. 341, 20 September 2013. It will be available to view online at http://www.sciencemag.org/lookup/doi/10.1126/science.1239450

Colossal New Predatory Dino Terrorized Early Tyrannosaurs

November 30th, 2013

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A new species of carnivorous dinosaur — one of the three largest ever discovered in North America — lived alongside and competed with small-bodied tyrannosaurs 98 million years ago. This newly discovered species, Siats meekerorum, (pronounced see-atch) was the apex predator of its time, and kept tyrannosaurs from assuming top predator roles for millions of years.

Named after a cannibalistic man-eating monster from Ute tribal legend, Siats is a species of carcharodontosaur, a group of giant meat-eaters that includes some of the largest predatory dinosaurs ever discovered. The only other carcharodontosaur known from North America is Acrocanthosaurus, which roamed eastern North America more than 10 million years earlier. Siats is only the second carcharodontosaur ever discovered in North America; Acrocanthosaurus, discovered in 1950, was the first.

This is an illustration of Siats meekerorum. (Credit: Artwork by Jorge Gonzales)

“It’s been 63 years since a predator of this size has been named from North America,” says Lindsay Zanno, a North Carolina State University paleontologist with a joint appointment at the North Carolina Museum of Natural Sciences, and lead author of a Nature Communications paper describing the find. “You can’t imagine how thrilled we were to see the bones of this behemoth poking out of the hillside.”Zanno and colleague Peter Makovicky, from Chicago’s Field Museum of Natural History, discovered the partial skeleton of the new predator in Utah’s Cedar Mountain Formation in 2008. The species name acknowledges the Meeker family for its support of early career paleontologists at the Field Museum, including Zanno.

The recovered specimen belonged to an individual that would have been more than 30 feet long and weighed at least four tons. Despite its giant size, these bones are from a juvenile. Zanno and Makovicky theorize that an adult Siats might have reached the size of Acrocanthosaurus, meaning the two species vie for the second largest predator ever discovered in North America. Tyrannosaurus rex, which holds first place, came along 30 million years later and weighed in at more than twice that amount.

Although Siats and Acrocanthosaurus are both carcharodontosaurs, they belong to different sub-groups. Siats is a member of Neovenatoridae, a more slender-bodied group of carcharodontosaurs. Neovenatorids have been found in Europe, South America, China, Japan and Australia. However, this is the first time a neovenatorid has ever been found in North America.

Siats terrorized what is now Utah during the Late Cretaceous period (100 million years ago to 66 million years ago). It was previously unknown who the top meat-eater was in North America during this period. “Carcharodontosaurs reigned for much longer in North America than we expected,” says Zanno. In fact, Siats fills a gap of more than 30 million years in the fossil record, during which time the top predator role changed hands from carcharodontosaurs in the Early Cretaceous to tyrannosaurs in the Late Cretaceous.

The lack of fossils left paleontologists unsure about when this change happened and if tyrannosaurs outcompeted carcharodontosaurs, or were simply able to assume apex predator roles following carcharodontosaur extinction. It is now clear that Siats’ large size would have prevented smaller tyrannosaurs from taking their place atop the food chain.

“The huge size difference certainly suggests that tyrannosaurs were held in check by carcharodontosaurs, and only evolved into enormous apex predators after the carcharodontosaurs disappeared,” says Makovicky. Zanno adds, “Contemporary tyrannosaurs would have been no more than a nuisance to Siats, like jackals at a lion kill. It wasn’t until carcharodontosaurs bowed out that the stage could be set for the evolution of T. rex.”

At the time Siats reigned, the landscape was lush, with abundant vegetation and water supporting a variety of plant-eating dinosaurs, turtles, crocodiles, and giant lungfish. Other predators inhabited this ecosystem, including early tyrannosaurs and several species of other feathered dinosaurs that have yet to be described by the team. “We have made more exciting discoveries including two new species of dinosaur,” Makovicky says.

“Stay tuned,” adds Zanno. “There are a lot more cool critters where Siats came from.”

All fieldwork was conducted under permits through the Bureau of Land Management and funded by the Field Museum. Research was funded by North Carolina State University, North Carolina Museum of Natural Sciences and the Field Museum.

Ancient Minerals: Which Gave Rise to Life?

November 29th, 2013

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Life originated as a result of natural processes that exploited early Earth’s raw materials. Scientific models of life’s origins almost always look to minerals for such essential tasks as the synthesis of life’s molecular building blocks or the supply of metabolic energy. But this assumes that the mineral species found on Earth today are much the same as they were during Earth’s first 550 million years — the Hadean Eon — when life emerged. A new analysis of Hadean mineralogy challenges that assumption.

The work is published in American Journal of Science.

Carnegie’s Robert Hazen compiled a list of every plausible mineral species on the Hadean Earth and concludes that no more than 420 different minerals — about 8 percent of the nearly 5,000 species found on Earth today — would have been present at or near Earth’s surface.

The magnesium silicate forsterite was one of the most abundant minerals in the Hadean Eon, and it played a major role in Earth’s near-surface processes. The green color of this mineral (which is also known as the semi-precious gemstone peridot, the birthstone of August) is caused by small amounts iron. The iron can react with seawater to promote chemical reactions that may have played a role in life’s origins. (Credit: Robert Downs, University of Arizona, Ruff Project)

“This is a consequence of the limited ways that minerals might have formed prior to 4 billion years ago,” Hazen explained. “Most of the 420 minerals of the Hadean Eon formed from magma — molten rock that slowly crystallized at or near Earth’s surface — as well as the alteration of those minerals when exposed to hot water.”

By contrast, thousands of mineral species known today are the direct result of growth by living organisms, such as shells and bones, as well as life’s chemical byproducts, such as oxygen from photosynthesis. In addition, hundreds of other minerals that incorporate relatively rare elements such as lithium, beryllium, and molybdenum appear to have taken a billion years or more to first appear because it is difficult to concentrate these elements sufficiently to form new minerals. So those slow-forming minerals are also excluded from the time of life’s origins.

“Fortunately for most origin-of-life models, the most commonly invoked minerals were present on early Earth,” Hazen said.

For example, clay minerals — sometimes theorized by chemists to trigger interesting reactions — were certainly available. Sulfide minerals, including reactive iron and nickel varieties, were also widely available to catalyze organic reactions. However, borate and molybdate minerals, which are relatively rare even today, are unlikely to have occurred on the Hadean Earth and call into question origin models that rely on those mineral groups.

Several questions remain unanswered and offer opportunities for further study of the paleomineralogy of the Hadean Eon. For example, the Hadean Eon differs from today in the frequent large impacts of asteroids and comets — thousands of collisions by objects with diameters from a mile up to 100 miles. Such impacts would have caused massive disruption of Earth’s crust, with extensive fracture zones that were filled with hot circulating water. Such hydrothermal areas could have created complex zones with many exotic minerals.

This study also raises the question of how other planets and moons evolved mineralogically. Hazen suggests that Mars today may have progressed only as far as Earth’s Hadean Eon. As such, Mars may be limited to a similar suite of no more than about 400 different mineral species. Thanks to the Curiosity rover, we may soon know if that’s the case.

Intact baby dinosaur found in Canada

November 28th, 2013

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The tiny, intact skeleton of a baby rhinoceroslike dinosaur has been unearthed in Canada.

The toddler was just 3 years old and 5 feet (1.5 meters) long when it wandered into a river near Alberta, Canada, and drowned about 70 million years ago. The beast was so well-preserved that some of its skin left impressions in the nearby rock.

Philip J. Currie, Robert Holmes, Michael Ryan Clive Coy, Eva B. Koppelhus
The smallest intact ceratopsid skeleton wa ever found was recently unearthed in Alberta

The fossil is the smallest intact skeleton ever found from a group of horned, plant-eating dinosaurs known as ceratopsids, a group that includes the iconic Triceratops.

Rare find
Finding intact baby dinosaurs is incredibly rare.

“The big ones just preserve better: They don’t get eaten, they don’t get destroyed by animals,” said study co-author Philip Currie, a paleobiologist at the University of Alberta. “You always hope you’re going to find something small and that it will turn out to be a dinosaur.”

Paleontologists had unearthed a few individual bones from smaller ceratopsids in the past. But without intact juvenile skeletons, such bones aren’t very useful, as scientists don’t really know how each bone changes during each stage of the animals’ lives, Currie said.

The team was bone-hunting in Dinosaur Provincial Park in Alberta when Currie came upon what looked like a turtle shell sticking out from a hillside. Upon closer inspection, the fossil turned out to be a frill, the bony decorative headgear that surrounds the back of the head in ceratopsids.

When the team excavated, they found the fossilized skeleton of a tiny dinosaur they identified as a Chasmosaurus belli, a species commonly found in the area.

most intact

Drowning victim
Amazingly, almost the entire skeleton was intact, although sometime in the past, a sinkhole had opened up below the beast and the forelimbs had fallen away into an abyss. The fossil was so well-preserved that the tiny, rosettelike pattern on its skin was imprinted in the rock below the dinosaur.

Based on its size, the team estimates the dinosaur was about 3 years old — just out of infancy — when it perished. (Like humans, these dinosaurs typically take about 20 years to reach maturity, at which point they have 6.5-foot-long (2 meters) skulls and weigh 3 to 4 tons.)

bare fossil

The fossil was found in sediments associated with watery environments and didn’t have any bite marks or trace of injury, so it’s likely the dino toddler likely drowned.

“I think it may have just gotten trapped out of its league in terms of water current,” Currie told LiveScience.

Soon after, the baby dinosaur was buried by sediments and left untouched for millions of years.

Growth rates
Aside from being cute, the new fossil helps paleontologists understand how these plant-eating dinosaurs grew. Paleontologists can then better identify and age the myriad individual bones from juveniles discovered over the years.

Already, the team has learned that Chasmosaur juvenile frills look different from those on adults, and that limb proportions don’t change much as they grow. Predatory theropods such as Tyrannosaurus rex have disproportionately long limbs as juveniles, presumably to keep up with the adults in the pack.

By contrast, “in Chasmosaurians, the proportions are essentially the same, which probably means the adults were probably never moving that fast,” Currie said. “There was never priority for these animals to run to keep up with the adults.”

Iron Preserves, Hides Ancient Tissues in Fossilized Remains

November 27th, 2013

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New research from North Carolina State University shows that iron may play a role in preserving ancient tissues within dinosaur fossils, but also may hide them from detection. The finding could open the door to the recovery of more ancient tissues from within fossils.

Mary Schweitzer, an NC State paleontologist with a joint appointment at the N. C. Museum of Natural Sciences, first announced the surprising preservation of soft tissues in a T. rex fossil in 2005. Her subsequent work identified proteins in the soft tissue that seemed to confirm that the tissue was indeed T. rex tissue that had been preserved for millions of years. But the findings remained controversial in part because no one understood the chemical processes behind such preservation.

Schweitzer’s latest research shows that the presence of hemoglobin — the iron-containing molecule that transports oxygen in red blood cells — may be the key to both preserving and concealing original ancient proteins within fossils. Her results appear in Proceedings of the Royal Society B.

“Iron is necessary for survival, but it’s also highly reactive and destructive in living tissues, which is why our bodies have proteins that transport iron molecules to where they are needed but protect us from unwanted reactions at the same time,” Schweitzer says. “When we die, that protective mechanism breaks down and the iron is turned loose on our tissues — and that destructive process can act in much the same way formaldehyde does to preserve the tissues and proteins.”

Hemoglobin seems to be the key. Both birds and crocodiles, the dinosaur’s closest living relatives, have large, nucleated red blood cells. Therefore they also have more hemoglobin per cell than mammals. If dinosaur blood cells were similar to either one of those species, which seems likely, then their blood cells would also contain much more hemoglobin than human cells, amplifying iron’s preservative effect on the tissues. If the hemoglobin were contained in a bone in a sandstone environment, keeping it dry and insulated from microbes, preservation becomes more likely.

Schweitzer and her team noticed that iron particles are intimately associated with the soft tissues preserved in dinosaurs. But when they chelated — or removed the iron from — soft tissues taken from a T. rex and a Brachyolophosaurus, the chelated tissues reacted much more strongly to antibodies that detect the presence of protein, suggesting that the iron may be masking their presence in these preserved tissues. They then tested the preservation hypothesis by using blood vessels and cells taken from modern ostrich bone. They soaked some of these vessels in hemoglobin taken from red blood cells, while placing other vessels in water. Two years later, the hemoglobin-treated soft vessels remained intact, while those soaked in water degraded in less than a week.

“We know that iron is always present in large quantities when we find well-preserved fossils, and we have found original vascular tissues within the bones of these animals, which would be a very hemoglobin-rich environment after they died,” Schweitzer says. “We also know that iron hinders just about every technique we have to detect proteins. So iron looks like it may be both the mechanism for preservation and the reason why we’ve had problems finding and analyzing proteins that are preserved.”

The research was funded by the National Science Foundation and the David and Lucile Packard Foundation. Research assistant Wenxia Zhang and former graduate student Timothy Cleland (now at Rensselaer Polytechnic Institute) contributed to the work, which was also done in collaboration with scientists at University of California-Berkeley, Lawrence Berkeley National Labs, and the Children’s Hospital Oakland Research Institute (CHORI).

Drill Holes and Predation Traces versus Abrasion-Induced Artifacts Revealed by Tumbling Experiments

November 24th, 2013

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Drill holes made by predators in prey shells are widely considered to be the most unambiguous bodies of evidence of predator-prey interactions in the fossil record. However, recognition of traces of predatory origin from those formed by abiotic factors still waits for a rigorous evaluation as a prerequisite to ascertain predation intensity through geologic time and to test macroevolutionary patterns. New experimental data from tumbling various extant shells demonstrate that abrasion may leave holes strongly resembling the traces produced by drilling predators. They typically represent singular, circular to oval penetrations perpendicular to the shell surface. These data provide an alternative explanation to the drilling predation hypothesis for the origin of holes recorded in fossil shells. Although various non-morphological criteria (evaluation of holes for non-random distribution) and morphometric studies (quantification of the drill hole shape) have been employed to separate biological from abiotic traces, these are probably insufficient to exclude abrasion artifacts, consequently leading to overestimate predation intensity. As a result, from now on, we must adopt more rigorous criteria to appropriately distinguish abrasion artifacts from drill holes, such as microstructural identification of micro-rasping traces.

Holes generated by tumbling experiments on various shells. show more (A) Brachiopod shell (Frenulina sanguinolenta) (GIUS 12-3616/Fs1) after 4 hours of tumbling. (B) Unionidae bivalve shell (GIUS 12-3616/U1) after 1 hour of tumbling. (C–D) Gastropod shells (Nassarius sp.) (GIUS 12-3616/N1-2) after 2 hours of tumbling. (E–F) Close up of hole margins in Nassarius sp. doi:10.1371/journal.pone.0058528.g001

Holes generated by tumbling experiments on various shells.
(A) Brachiopod shell (Frenulina sanguinolenta) (GIUS 12-3616/Fs1) after 4 hours of tumbling. (B) Unionidae bivalve shell (GIUS 12-3616/U1) after 1 hour of tumbling. (C–D) Gastropod shells (Nassarius sp.) (GIUS 12-3616/N1-2) after 2 hours of tumbling. (E–F) Close up of hole margins in Nassarius sp.
doi:10.1371/journal.pone.0058528.g001

Two morphotypes of the inner outlines of holes and their frequency distribution (drawings by camera lucida). show more doi:10.1371/journal.pone.0058528.g002

Two morphotypes of the inner outlines of holes and their frequency distribution (drawings by camera lucida).
doi:10.1371/journal.pone.0058528.g002

Frequency distribution of holes in Nassarius sp. show more (A) Apertural view. (B) Abapertural view. doi:10.1371/journal.pone.0058528.g005

Frequency distribution of holes in Nassarius sp.
(A) Apertural view. (B) Abapertural view.
doi:10.1371/journal.pone.0058528.g005

Citation: Gorzelak P, Salamon MA, Trzęsiok D, Niedźwiedzki R (2013) Drill Holes and Predation Traces versus Abrasion-Induced Artifacts Revealed by Tumbling Experiments. PLoS ONE 8(3): e58528. doi:10.1371/journal.pone.0058528

Editor: David Caramelli, University of Florence, Italy