WFS News: New plate adds plot twist to ancient tectonic tale

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A microplate discovered off the west coast of Ecuador adds another piece to Earth’s tectonic puzzle, according to Rice University scientists.

Researchers led by Rice geophysicist Richard Gordon discovered the microplate, which they have named “Malpelo,” while analyzing the junction of three other plates in the eastern Pacific Ocean.

The Malpelo Plate, named for an island and an underwater ridge it contains, is the 57th plate to be discovered and the first in nearly a decade, they said. They are sure there are more to be found.

The research by Gordon, lead author Tuo Zhang and co-authors Jay Mishra and Chengzu Wang, all of Rice, appears in Geophysical Research Letters.

How do geologists discover a plate? In this case, they carefully studied the movements of other plates and their evolving relationships to one another as the plates move at a rate of millimeters to centimeters per year.

The Pacific lithospheric plate that roughly defines the volcanic Ring of Fire is one of about 10 major rigid tectonic plates that float and move atop Earth’s mantle, which behaves like a fluid over geologic time. Interactions at the edges of the moving plates account for most earthquakes experienced on the planet. There are many small plates that fill the gaps between the big ones, and the Pacific Plate meets two of those smaller plates, the Cocos and Nazca, west of the Galapagos Islands.

One way to judge how plates move is to study plate-motion circuits, which quantify how the rotation speed of each object in a group (its angular velocity) affects all the others. Rates of seafloor spreading determined from marine magnetic anomalies combined with the angles at which the plates slide by each other over time tells scientists how fast the plates are turning.

“When you add up the angular velocities of these three plates, they ought to sum to zero,” Gordon said. “In this case, the velocity doesn’t sum to zero at all. It sums to 15 millimeters a year, which is huge.”

That made the Pacific-Cocos-Nazca circuit a misfit, which meant at least one other plate in the vicinity had to make up the difference. Misfits are a cause for concern — and a clue.

Knowing the numbers were amiss, the researchers drew upon a Columbia University database of extensive multibeam sonar soundings west of Ecuador and Colombia to identify a previously unknown plate boundary between the Galapagos Islands and the coast.

Previous researchers had assumed most of the region east of the known Panama transform fault was part of the Nazca plate, but the Rice researchers determined it moves independently. “If this is moving in a different direction, then this is not the Nazca plate,” Gordon said. “We realized this is a different plate and it’s moving relative to the Nazca.”

Misfit plates in the Pacific led Rice University scientists to the discovery of the Malpelo Plate between the Galapagos Islands and the South American coast. Credit: Illustration by Tuo Zhang/Rice University

Misfit plates in the Pacific led Rice University scientists to the discovery of the Malpelo Plate between the Galapagos Islands and the South American coast.Credit: Illustration by Tuo Zhang/Rice University

Evidence for the Malpelo plate came with the researchers’ identification of a diffuse plate boundary that runs from the Panama Transform Fault eastward to where the diffuse plate boundary intersects a deep oceanic trench just offshore of Ecuador and Colombia.

“A diffuse boundary is best described as a series of many small, hard-to-spot faults rather than a ridge or transform fault that sharply defines the boundary of two plates,” Gordon said. “Because earthquakes along diffuse boundaries tend to be small and less frequent than along transform faults, there was little information in the seismic record to indicate this one’s presence.”

“With the Malpelo accounted for, the new circuit still doesn’t close to zero and the shrinking Pacific Plate isn’t enough to account for the difference either,” Zhang said. “The nonclosure around this triple junction goes down — not to zero, but only to 10 or 11 millimeters a year.

“Since we’re trying to understand global deformation, we need to understand where the rest of that velocity is going,” he said. “So we think there’s another plate we’re missing.”

Plate 58, where are you?

Gordon is the W.M. Keck Professor of Geophysics. Zhang and Wang are Rice graduate students and Mishra is a Rice alumnus.

The National Science Foundation supported the research.

Journal Reference:Tuo Zhang, Richard G. Gordon, Jay K. Mishra, Chengzu Wang. The Malpelo Plate Hypothesis and Implications for Non-closure of the Cocos-Nazca-Pacific Plate Motion Circuit. Geophysical Research Letters, 2017; DOI: 10.1002/2017GL073704   & Rice University. “New plate adds plot twist to ancient tectonic tale: Scientists say Malpelo microplate helps resolve geological misfit under Pacific Ocean.” ScienceDaily. ScienceDaily, 14 August 2017. <www.sciencedaily.com/releases/2017/08/170814104409.

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WFS News: Unique imaging of a dinosaur’s skull tells evolutionary tale

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Researchers using Los Alamos’ unique neutron-imaging and high-energy X-ray capabilities have exposed the inner structures of the fossil skull of a 74-million-year-old tyrannosauroid dinosaur nicknamed the Bisti Beast in the highest-resolution scan of tyrannosaur skull ever done. The results add a new piece to the puzzle of how these bone-crushing top predators evolved over millions of years.

“Normally, we look at a variety of thick, dense objects at Los Alamos for defense programs, but the New Mexico Museum of Natural History and Science was interested in imaging a very large fossil to learn about what’s inside,” said Ron Nelson, of the Laboratory’s Physics Division. Nelson was part of a team that included staff from Los Alamos National Laboratory, the museum, the University of New Mexico and the University of Edinburgh. “It turns out that high energy neutrons are an interesting and unique way to image something of this size.”

The results helped the team determine the skull’s sinus and cranial structure. Initial viewing of the computed tomography (CT) slices showed preservation of un-erupted teeth, the brain cavity, internal structure in some bones, sinus cavities, pathways of some nerves and blood vessels, and other anatomical structures. These imaging techniques have revolutionized the study of paleontology over the past decade, allowing paleontologists to gain essential insights into the anatomy, development and preservation of important specimens. Team members will present their findings on the fossil, Bistahieversor sealeyi, August 23 at the annual Society of Vertebrate Paleontology meeting in Calgary, Alberta.

This is a 3-D image of Bistahieversor sealeyi, which was found in the Bisti Badlands in New Mexico and Imaged at Los Alamos' unique facilities. Credit: Los Alamos National Laboratory

This is a 3-D image of Bistahieversor sealeyi, which was found in the Bisti Badlands in New Mexico and Imaged at Los Alamos’ unique facilities.Credit: Los Alamos National Laboratory

To peer inside the 40-inch skull, which was found in 1996 in the Bisti/De-Na-Zin Wilderness Area near Farmington, N.M. the Los Alamos team combined neutron and X-ray CT to extract anatomical information not accessible otherwise and without the risk of damaging the irreplaceable fossil. Los Alamos is one of a few places in the world that can perform both methods on samples ranging from the very small to the very large scale.

The thickness of the skull required higher energy X-rays than those typically available to adequately penetrate the fossil. The Lab’s microtron electron accelerator produced sufficiently high-energy X-rays.

To provide an alternate view inside the skull, the team also used a newly developed, high-energy neutron imaging technique with neutrons produced by the proton accelerator at the Los Alamos Neutron Science Center (LANSCE). The neutrons interact with the nuclei rather than the electrons in the skull, as X-rays do, and thus have different elemental sensitivity. This provides complementary information to that obtained with X-rays.

The team’s study illuminates the Bisti Beast’s place in the evolutionary tree that culminated in Tyrannosaurus rex.

“The CT scans help us figure out how the different species within the T. rex family related to each other and how they evolved,” said Thomas Williamson, Curator of Paleontology at the New Mexico museum. “The Bistahieversor represents the most basal tyrannosaur to have the big-headed, bone-crushing adaptations and almost certainly the small forelimbs. It was living alongside species more closely related to T. rex, the biggest and most derived tyrannosaur of all, which lived about 66 million years ago. Bistahieversor lived almost 10 million years before T. rex, but it also was a surviving member of a lineage that retained many of the primitive features from even farther back closer to when tyrannosaurs underwent their transition to bone-crushing.”

The Bisti Beast skull is the largest object to date for which full, high-resolution neutron and X-ray CT scans have been performed at the Laboratory and required innovations both to image the entire skull and to handle the image reconstruction from the resulting large data sets.

This work advances the state of the art in imaging capabilities at the Laboratory and is already proving useful in imaging larger programmatic items related to the Laboratory’s national security mission.

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Citation: DOE/Los Alamos National Laboratory. “Unique imaging of a dinosaur’s skull tells evolutionary tale: Collaboration creates highest-resolution scan of a large tyrannosaur skull.” ScienceDaily. ScienceDaily, 15 August 2017. <www.sciencedaily.com/releases/2017/08/170815095038.htm>

WFS News:Teleosaster creasyi,Fossil of a new species of starfish

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A new species of ancient starfish-like sea creature has been discovered in a remote town nearly 200 kilometres from the ocean by University of Western Australia, Curtin University and University of Cambridge researchers.

Brittle stars, or ophiuroids, are closely related to starfish.More than 2,000 species are found in oceans today but the new species, Teleosaster creasyi, dates back hundreds of millions of years.

University of Western Australia (UWA) Earth Sciences researcher Dr Aaron Hunter said the discovery was the first time brittle star fossils had been recorded in WA.Dr Hunter said the fossil site, 173km east of Carnarvon, was one of the most spectacular fossil sites in the world.

“It’s quite exceptional,” he said.

“They have been buried in those rocks, deep down, for millions and millions of years.”They are beautifully preserved … as if they died yesterday.”

Teleosaster creasyi is the first brittle star described from the fossil record in WA. Supplied: Kenneth McNamara

Teleosaster creasyi is the first brittle star described from the fossil record in WA.
Supplied: Kenneth McNamara

“You can see them as if they have been flattened on the rocks.”Dr Hunter said north-west Australia was recognised for its fossils.

“If you go to areas of the north-west of WA you find fossils everywhere,” he said.

“You just need to know where to look.”

Bigger and more primitive models:Dr Hunter said the fossils were found about 15 years ago but it had taken a long time for scientists to establish their significance to the WA fossil record.

The brittle stars are about the size of saucers, which Dr Hunter said was more than 10 times the size of other species.

Some ophiuroids grow to the size of dinner plates.Dr Hunter said archaic brittle stars were primitive versions of the starfish we see today.

“Today we’re looking at … the advanced model,” he said.”[Ancient brittle stars] are like the great, great, great, great grandparents of modern-day ophiuroids.”

The fossil slab provides a snapshot of marine life 275-million-years ago. Supplied: Kenneth McNamara

The fossil slab provides a snapshot of marine life 275-million-years ago.
Supplied: Kenneth McNamara

‘Not unusual’ to find marine fossils inland Dr Hunter said it was not unusual to find ancient sea creatures so far inland.
The Gascoyne Junction fossil slab provides a snapshot of ancient Australian marine life. Supplied: Kenneth McNamara

The Gascoyne Junction fossil slab provides a snapshot of ancient Australian marine life.
Supplied: Kenneth McNamara

“Although today we might think it’s strange that they are … miles from the sea, in the past that was the sea,” he said.

“When they were preserved, Australia was a lot further south and it was a lot colder. It was like Antarctica today.”

Dr Hunter said over a very long period of time, Australia moved up to the country’s present position and the rocks containing the fossils were slowly brought to the surface.The discovery sheds new light on the evolution of brittle stars.

“These ones have survived longer [than previously thought]”, Dr Hunter said.

“The reason is … because they were living in this cold water, hiding away from the tropical world where things were evolving faster.”He said researchers hope the slab of siltstone the brittle stars and other fossilised marine life were preserved in could be displayed at the new Western Australia Museum.

Source:ABC North West WA,By Lisa Morrison

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Remobilization of crustal carbon may dominate volcanic arc emissions

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A new analysis suggests that much of the carbon released from volcanic arcs, chains of volcanoes that arise along the tectonic plates of a subduction zone, comes from remobilizing limestone reservoirs in the Earth’s crust. Previous research suggested carbon was sourced from the mantle as a result of the subduction process.

The discovery ultimately impacts the amount of organic carbon scientists believe was buried in the past. Carbon cycling between surface reservoirs and the mantle over geologic history is important because the imbalance greatly influences the amount of total carbon at Earth’s surface. However, the source for carbon from volcanic arc outgassing remained uncertain.

This image depicts results by Mason et al. This material relates to a paper that appeared in the July 21, 2017 issue of Science, published by AAAS. The paper, by E. Mason at University of Cambridge in Cambridge, UK, and colleagues was titled, 'Remobilization of crustal carbon may dominate volcanic arc emissions.' Credit: Carla Schaffer / AAA

This image depicts results by Mason et al. This material relates to a paper that appeared in the July 21, 2017 issue of Science, published by AAAS. The paper, by E. Mason at University of Cambridge in Cambridge, UK, and colleagues was titled, ‘Remobilization of crustal carbon may dominate volcanic arc emissions.’Credit: Carla Schaffer / AAA

Emily Mason and colleagues compiled a global data set of carbon and helium isotopes to determine the origin of the carbon. The data reveal that many volcanic arcs mobilize carbon from large, crustal carbonate platforms — particularly in Italy, the Central American Volcanic Arc, Indonesia, and Papua New Guinea.

In contrast, arcs located in the northern Pacific, such as Japan and Kuril-Kamchatka, release carbon dioxide with an isotope signature indicative of a mantle source.

The recognition of a large amount of crustal carbon in the overall carbon isotope signature requires, from a mass balance consideration, downward revision of how much organic carbon was buried in the past.

Journal Reference:Emily Mason, Marie Edmonds, Alexandra V. Turchyn. Remobilization of crustal carbon may dominate volcanic arc emissions. Science, 2017; 357 (6348): 290 DOI: 10.1126/science.aan5049

American Association for the Advancement of Science. “Crustal limestone platforms feed carbon to many of Earth’s arc volcanoes.” ScienceDaily. ScienceDaily, 20 July 2017. <www.sciencedaily.com/releases/2017/07/170720142223.htm>.
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WFS News: A new species of Tritylodontid found in Japan

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 Teeth can reveal a lot, such as how the earliest mammals lived with their neighbors. Researchers have uncovered dozens of fossilized teeth in Kuwajima, Japan and identified this as a new species of tritylodontid, an animal family that links the evolution of mammals from reptiles. This finding suggests that tritylodontids co-existed with some of the earliest mammal species for millions of years, overturning beliefs that mammals wiped out mammal-like reptiles soon after they emerged.

Tritylodontids are the last known family of near-mammalian reptiles, before mammals with features such as advanced hearing evolved.

“Tritylodontids were herbivores with unique sets of teeth which intersect when they bite,” explains study author Hiroshige Matsuoka, based at Kyoto University. “They had pretty much the same features as mammals — for instance they were most likely warm-blooded — but taxonomically speaking they were reptiles, because in their jaws they still had a bone that in mammals is used for hearing.”

Tritylodontids are the last known family of near-mammalian reptiles, before mammals with features such as advanced hearing evolved. Researchers have uncovered dozens of fossilized teeth in Kuwajima, Japan and identified this as a new species of tritylodontid. This suggests that tritylodontids co-existed with some of the earliest mammal species for millions of years. Credit: Seishi Yamamoto/Hiroshige Matsuoka

Tritylodontids are the last known family of near-mammalian reptiles, before mammals with features such as advanced hearing evolved. Researchers have uncovered dozens of fossilized teeth in Kuwajima, Japan and identified this as a new species of tritylodontid. This suggests that tritylodontids co-existed with some of the earliest mammal species for millions of years.
Credit: Seishi Yamamoto/Hiroshige Matsuoka

While excavating a geologic layer from the Cretaceous era in Kuwajima, researchers found fossils of dinosaurs, turtles, lizards, fish, many types of plants, and Mesozoic mammals. Among these were more than 250 tritylodontid teeth, the first to be found in Japan.

Tritylodontids lived in the Jurassic era and proliferated worldwide, but were thought to have died out as herbivorous mammals took over their ecological role in the late Jurassic. “This made sense, because otherwise tritylodontids and the herbivorous mammals would have competed for the same niche,” says Matsuoka.

But according to the team’s finding, trytylodontids seem to have survived at least 30 million years longer than what paleontologists had believed.

“This raises new questions about how tritylodontids and their mammalian neighbors shared or separated ecological roles,” says Matsuoka.

The study is also the first of its kind to depend solely on details from teeth to determine whether the species is new, and also where it sits on the evolutionary tree.

“Usually fossils are identified as a new species only when a relatively complete set of structures like a jaw bone are found. In these cases, characteristics of teeth tend to be described only briefly,” adds Matsuoka. “Tritylodontid teeth have three rows of 2-3 cusps. This time we paid attention to fine details like the size and shape of each cusp. By using this method it should be possible to characterize other species on the evolutionary tree as well.”

“Because fossils of so many diverse families of animals are to be found in Kuwajima, we’d like to keep investigating the site to uncover things not just about individual species, but also about entire ecological dynamics.”

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Journal Reference:Hiroshige Matsuoka, Nao Kusuhashi, Ian J. Corfe. A new Early Cretaceous tritylodontid (Synapsida, Cynodontia, Mammaliamorpha) from the Kuwajima Formation (Tetori Group) of central Japan. Journal of Vertebrate Paleontology, 2016; e1112289 DOI: 10.1080/02724634.2016.1112289
Kyoto University. “Mammal-like reptile survived much longer than thought: Fossils in Japan overturn widely accepted theory about tritylodontid extinction.” ScienceDaily. ScienceDaily, 25 April 2016. <www.sciencedaily.com/releases/2016/04/160425112655.htm>.

The birth and death of a tectonic plate

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Several hundred miles off the Pacific Northwest coast, a small tectonic plate called the Juan de Fuca is slowly sliding under the North American continent. This subduction has created a collision zone with the potential to generate huge earthquakes and accompanying tsunamis, which happen when faulted rock abruptly shoves the ocean out of its way.

In fact, this region represents the single greatest geophysical hazard to the continental United States; quakes centered here could register as hundreds of times more damaging than even a big temblor on the San Andreas Fault. Not surprisingly, scientists are interested in understanding as much as they can about the Juan de Fuca Plate.

This microplate is “born” just 300 miles off the coast, at a long range of underwater volcanoes that produce new crust from melt generated deep below. Part of the global mid-ocean ridge system that encircles the planet, these regions generate 70 percent of Earth’s tectonic plates. However, because the chains of volcanoes lie more than a mile beneath the sea surface, scientists know surprisingly little about them.

Ocean-bottom seismometers aboard the R/V Welcoma were deployed in the first year of the Cascadia Initiative. Credit: Dave O'Gorman

Ocean-bottom seismometers aboard the R/V Welcoma were deployed in the first year of the Cascadia Initiative.Credit: Dave O’Gorman

UC Santa Barbara geophysicist Zachary Eilon and his co-author Geoff Abers at Cornell University have conducted new research — using a novel measurement technique — that has revealed a strong signal of seismic attenuation or energy loss at the mid-ocean ridge where the Juan de Fuca Plate is created. The researchers’ attenuation data imply that molten rock here is found even deeper within Earth than scientists had previously thought. This in turn helps scientists understand the processes by which Earth’s tectonic plates are built, as well as the deep plumbing of volcanic systems. The results of the work appear in the journal Science Advances.

“We’ve never had the ability to measure attenuation this way at a mid-ocean ridge before, and the magnitude of the signal tells us that it can’t be explained by shallow structure,” said Eilon, an assistant professor in UCSB’s Department of Earth Science. “Whatever is down there causing all this seismic energy to be lost extends really deep, at least 200 kilometers beneath the surface. That’s unexpected, because we think of the processes that give rise to this — particularly the effect of melting beneath the surface — as being shallow, confined to 60 km or less.”

According to Eilon’s calculations, the narrow strip underneath the mid-ocean ridge, where hot rock wells up to generate the Juan de Fuca Plate, has very high attenuation. In fact, its levels are as high as scientists have seen anywhere on the planet. His findings also suggest that the plate is cooling faster than expected, which affects the friction at the collision zone and the resulting size of any potential megaquake.

Seismic waves begin at an earthquake and radiate away from it. As they disperse, they lose energy. Some of that loss is simply due to spreading out, but another parameter also affects energy loss. Called the quality factor, it essentially describes how squishy Earth is, Eilon said. He used the analogy of a bell to explain how the quality factor works.

“If I were to give you a well-made bell and you were to strike it once, it would ring for a long time,” he explained. “That’s because very little of the energy is actually being lost with each oscillation as the bell rings. That’s very low attenuation, very high quality. But if I give you a poorly made bell and you strike it once, the oscillations will die out very quickly. That’s high attenuation, low quality.”

Eilon looked at the way different frequencies of seismic waves attenuated at different rates. “We looked not only at how much energy is lost but also at the different amounts by which various frequencies are delayed,” he explained. “This new, more robust way of measuring attenuation is a breakthrough that can be applied in other systems around the world.

“Attenuation is a very hard thing to measure, which is why a lot of people ignore it,” Eilon added. “But it gives us a huge amount of new information about Earth’s interior that we wouldn’t have otherwise.”

Next year, Eilon will be part of an international effort to instrument large unexplored swaths of the Pacific with ocean bottom seismometers. Once that data has been collected, he will apply the techniques he developed on the Juan de Fuca in the hope of learning more about what lies beneath the seafloor in the old oceans, where mysterious undulations in Earth’s gravity field have been measured.

“These new ocean bottom data, which are really coming out of technological advances in the instrumentation community, will give us new abilities to see through the ocean floor,” Eilon said. “This is huge because 70 percent of Earth’s surface is covered by water and we’ve largely been blind to it — until now.

“The Pacific Northwest project was an incredibly ambitious community experiment,” he said. “Just imagine the sort of things we’ll find out once we start to put these instruments in other places.”

Source:University of California – Santa Barbara. “The birth and death of a tectonic plate.” ScienceDaily. ScienceDaily, 24 May 2017. <www.sciencedaily.com/releases/2017/05/170524152628.htm>

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WFS News: Maiopatagium furculiferum,First winged mammals from the Jurassic period?

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Two 160 million-year-old mammal fossils discovered in China show that the forerunners of mammals in the Jurassic Period evolved to glide and live in trees. With long limbs, long hand and foot fingers, and wing-like membranes for tree-to-tree gliding, Maiopatagium furculiferum and Vilevolodon diplomylos are the oldest known gliders in the long history of early mammals.

The new discoveries suggest that the volant, or flying, way of life evolved among mammalian ancestors 100 million years earlier than the first modern mammal fliers. The fossils are described in two papers published this week in Nature by an international team of scientists from the University of Chicago and Beijing Museum of Natural History.

Photograph of the fossil of gliding mammaliaform Maiopatagium furculiferum (type specimen from Beijing Museum of Natural History BMNH 2940). Credit: Zhe-Xi Luo/UChicago

Photograph of the fossil of gliding mammaliaform Maiopatagium furculiferum (type specimen from Beijing Museum of Natural History BMNH 2940).Credit: Zhe-Xi Luo/UChicago

“These Jurassic mammals are truly ‘the first in glide,'” said Zhe-Xi Luo, PhD, professor of organismal biology and anatomy at the University of Chicago and an author on both papers. “In a way, they got the first wings among all mammals.”

“With every new mammal fossil from the Age of Dinosaurs, we continue to be surprised by how diverse mammalian forerunners were in both feeding and locomotor adaptations. The groundwork for mammals’ successful diversification today appears to have been laid long ago,” he said.

Adaptations in anatomy, lifestyle and diet

The ability to glide in the air is one of the many remarkable adaptations in mammals. Most mammals live on land, but volant mammals, including flying squirrels and bats that flap bird-like wings, made an important transition between land and aerial habitats. The ability to glide between trees allowed the ancient animals to find food that was inaccessible to other land animals. That evolutionary advantage can still be seen among today’s mammals such as flying squirrels in North America and Asia, scaly-tailed gliders of Africa, marsupial sugar gliders of Australia and colugos of Southeast Asia.

The Jurassic Maiopatagium and Vilevolodon are stem mammaliaforms, long-extinct relatives of living mammals. They are haramiyidans, an entirely extinct branch on the mammalian evolutionary tree, but are considered to be among forerunners to modern mammals. Both fossils show the exquisitely fossilized, wing-like skin membranes between their front and back limbs. They also show many skeletal features in their shoulder joints and forelimbs that gave the ancient animals the agility to be capable gliders. Evolutionarily, the two fossils, discovered in the Tiaojishan Formation northeast of Beijing, China, represent the earliest examples of gliding behavior among extinct mammal ancestors.

The two newly discovered creatures also share similar ecology with modern gliders, with some significant differences. Today, the hallmark of most mammal gliders is their herbivorous diet that typically consists of seeds, fruits and other soft parts of flowering plants.

But Maiopatagium and Vilevolodon lived in a Jurassic world where the plant life was dominated by ferns and gymnosperm plants like cycads, gingkoes and conifers — long before flowering plants came to dominate in the Cretaceous Period, and their way of life was also associated with feeding on these entirely different plants. This distinct diet and lifestyle evolved again some 100 million years later among modern mammals, in examples of convergent evolution and ecology.

“It’s amazing that the aerial adaptions occurred so early in the history of mammals,” said study co-author David Grossnickle, a graduate student at the University of Chicago. “Not only did these fossils show exquisite fossilization of gliding membranes, their limb, hand and foot proportion also suggests a new gliding locomotion and behavior.”

Thriving among dinosaurs

Early mammals were once thought to have differences in anatomy from each other, with limited opportunities to inhabit different environments. The new glider fossils from the dinosaur-dominated Jurassic Period, along with numerous other fossils described by Luo and colleagues in the last 10 years, however, provide strong evidence that ancestral mammals adapted to their wide-ranging environments despite competition from dinosaurs.

“Mammals are more diverse in lifestyles than other modern land vertebrates, but we wanted to find out whether early forerunners to mammals had diversified in the same way,” Luo said. “These new fossil gliders are the first winged mammals, and they demonstrate that early mammals did indeed have a wide range of ecological diversity, which means dinosaurs likely did not dominate the Mesozoic landscape as much as previously thought.”

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Journal Reference:Qing-Jin Meng, David M. Grossnickle, Di Liu, Yu-Guang Zhang, April I. Neander, Qiang Ji, Zhe-Xi Luo. New gliding mammaliaforms from the Jurassic. Nature, 2017; DOI: 10.1038/nature23476
University of Chicago Medical Center. “First winged mammals from the Jurassic period discovered: 160-million-year-old fossils suggest a new model of life — gliding — for the forerunners of mammals, in an evolutionary parallel to modern mammal gliders.” ScienceDaily. ScienceDaily, 9 August 2017. <www.sciencedaily.com/releases/2017/08/170809140302.htm>.
 

WFS News: Well-preserved 110 MYO dinosaur found in Canada

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AN EXTRAORDINARILY well-preserved 110-million-year-old dinosaur found in a mine pit in Canada now has a name and evidence of a troubled past, researchers said Thursday.

With fossilized skin and scales, the dragon-like creature is actually a new kind of nodosaur, coined Borealopelta markmitchelli, after the museum technician Mark Mitchell who spent more than 7000 hours painstakingly removing rock from around the specimen.

The report in the journal Current Biology described it as “the best-preserved armored dinosaur ever found, and one of the best dinosaur specimens in the world.” The 5.5 meter creature was first discovered in 2011 by a mining machine operator named Shawn Funk, who was working at the Suncor Millennium Mine in Alberta.

This recent handout photograph obtained August 2, 2017, courtesy of the Royal Tyrrell Museum of Paleontology shows the well-preserved head of a 110-million-year-old Borealopelta markmitchelli. Picture: Royal Tyrrell Museum of PaleontologySource:AFP

This recent handout photograph obtained August 2, 2017, courtesy of the Royal Tyrrell Museum of Paleontology shows the well-preserved head of a 110-million-year-old Borealopelta markmitchelli. Picture: Royal Tyrrell Museum of PaleontologySource:AFP

The entire animal would have weighed more than 1,300 kilograms. The portion recovered spans from the snout to the hips.

Unlike most dinosaur specimens, which consist of skeletons or bone fragments, this one is three-dimensional and covered in preserved, scaly skin.

“If you just squint your eyes a bit, you could almost believe it was sleeping,” said lead author Caleb Brown, a scientist at the Royal Tyrrell Museum where the creature is on display.

“It will go down in science history as one of the most beautiful and best preserved dinosaur specimens — the Mona Lisa of dinosaurs.”

By studying its skin, researchers found that this plant-eater, though covered in armor and resembling a walking tank, likely faced a significant threat from meat-eating dinosaurs.

An analysis of the 5.5 metre specimen's form, complete with fully armored skin, suggests the creature had predators, despite the fact that it was the "dinosaur equivalent of a tank," weighing in at more than 1,300 kg. Picture: Royal Tyrrell Museum of PaleontologySource:AFP

An analysis of the 5.5 metre specimen’s form, complete with fully armored skin, suggests the creature had predators, despite the fact that it was the “dinosaur equivalent of a tank,” weighing in at more than 1,300 kg. Picture: Royal Tyrrell Museum of PaleontologySource:AFP

 That’s because it employed a shielding technique known as counter-shading, which is also used by many modern-day animals.

Researchers used chemical analysis of organic compounds in the dinosaur’s scales to reveal the pigmentation pattern of this new genus and species of dinosaur, showing it had reddish-brown pigmented skin with countershading across its the body.

This may have helped it blend in with the environment when approached by a taller predator, researchers say.

But most contemporary animals that have countershading — think deer, zebras or armadillos — are much smaller and more vulnerable as prey, signaling that this nodosaur faced a real struggle to survive.

“Strong predation on a massive, heavily-armored dinosaur illustrates just how dangerous the dinosaur predators of the Cretaceous must have been,” said Brown.

Scientists are continuing to study the animal for clues about its life, including its preserved gut contents to find out what it ate for its last meal.

They believe that when the dinosaur died, it fell into a river and was swept out to sea, where it sank on its back to the ocean floor.

The entire animal dubbed the "dinosaur equivalent of a tank” would have weighed more than 1,300 kilograms.

The entire animal dubbed the “dinosaur equivalent of a tank” would have weighed more than 1,300 kilograms.

At that time, Alberta was as warm as south Florida is today, and rivers and oceans likely spread far further inland than they do now.

The dinosaur was first unveiled to the public in May, but it didn’t yet have a formal name.

Source:http://www.news.com.au,Article AFP

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WFS News: Montsechia vidalii ,First Flower on Earth?

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Three was the magic number for the very first flowering plant. The largest study into their early evolution has concluded that its flowers probably had petal-like tepals and pollen-bearing stamens arranged in layered whorls of three. It bore similarities with magnolias, buttercups and laurels – but was unlike any living flower.

The origin of flowering plants and their rapid conquest of the world’s habitats has been a puzzle for nearly a century and a half. In 1879, Charles Darwin described it as an “abominable mystery” that flowers had evolved so late in the history of life yet were still able to take over from the more ancient seed-bearing pines and cycads.

Today, flowering plants account for nine out of every 10 plants – meaning they far outnumber the once-dominant seed plants like conifers that emerged between 350 and 310 million years ago.

Three-dimensional model of the ancestral flower reconstructed

Three-dimensional model of the ancestral flower reconstructed

Studying their evolutionary roots is tricky, though: the delicacy of flowers means they rarely become fossilised. The oldest so far discovered is the 130- million-year-old aquatic plant Montsechia vidalii unearthed in Spain in 2015. However it is thought that flowering plants first appeared much earlier than this, sometime between 250 and 140 million years ago.

Picking flower traits

To unravel what the very first flower was like, a 36-strong team led by Hervé Sauquet of the University of Paris-South, France, spent six years analysing the anatomical evidence of nearly every type of flowering plant to identify their most ancestral traits.

They calibrated their results with dates derived from molecular analyses and constructed evolutionary trees that modelled the earliest stages in flower evolution.

“We looked at the big bang of flowering plant evolution when they first evolved,” says Sauquet.

They discovered that the first flower probably had 11 or more tepals and stamens, generally grouped in threes and carried both male and female reproductive structures. It was arranged in a unique way unlike any living flower. It’s unclear how large the first flower was, but it may have been just 1 centimetre or less in diameter.

One surprise is how many petal-like tepals the first flower had compared with most living flowers. Reducing their number allowed later flowers to develop a dazzling array of specialised shapes and sizes and consequently diversify along with their animal pollinators into the enormous range of ecosystems  they occupy today. There are some 300,000 living flowering plants.

The findings mean that the living flowers identified as being most ancient, such as Amborella from New Caledonia, and water lilies, are actually quite evolved compared with their ancient ancestors.

Source: Article By James O’Donoghue,www.newscientist.com

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WFS News: Whether sills caused mass extinction?

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A study by a researcher in the Syracuse University College of Arts and Sciences offers new clues to what may have triggered the world’s most catastrophic extinction, nearly 252 million years ago.

James Muirhead, a research associate in the Department of Earth Sciences, is the co-author of an article in Nature Communications (Macmillan Publishers Limited, 2017) titled “Initial Pulse of Siberian Traps Sills as the Trigger of the End-Permian Mass Extinction.”

His research involves Seth Burgess, the article’s lead author and a geologist at the U.S. Geological Survey, and Samuel Bowring, the Robert R. Shock Professor of Geology at the Massachusetts Institute of Technology.

Their findings suggest that the formation of intrusive igneous rock, known as sills, sparked a chain of events that brought the Permian geological period to a close. In the process, more than 95 percent of marine species and 70 percent of land species vanished.

Seth Burgess, a geologist at the U.S. Geological Survey, studies a columnar joint in the Siberian Traps. Formed by the cooling of basaltic lava, these massive columns are peppered with orange lichen. Credit: Photo by Scott Simper

Seth Burgess, a geologist at the U.S. Geological Survey, studies a columnar joint in the Siberian Traps. Formed by the cooling of basaltic lava, these massive columns are peppered with orange lichen.Credit: Photo by Scott Simper

“There have been five major mass extinctions, since life originated on Earth more than 600 million years ago,” says Burgess, who works at the nexus of volcanic and tectonic processes. “Most of these events have been blamed, at various times, on volcanic eruptions and asteroids impacts. By reexamining the timing and connection between magmatism [the movement of magma], climate change and extinction, we’ve created a model that explains what triggered the end-Permian mass extinction.”

Central to their study is a large igneous province (LIP) in Russia called the Siberian Traps. Spanning more than 500,000 square miles, this rocky outpost was the site of nearly a million years of epic volcanic activity. Broad, flat volcanoes likely dispelled significant volumes of lava, ashes and gas, while pushing sulfur dioxide, carbon dioxide and methane to dangerous levels in the environment.

But that’s only part of the story.

“Until recently, the relative timing and duration of mass extinctions and LIP volcanism was obscured by age imprecision,” Muirhead says. “Our model is based on new, high-resolution age data that suggests surface lava flows erupted too early to drive mass extinction. Instead, there was a subinterval of magmatism — a shorter, particular part of the LIP — that triggered a cascade of events causing mass extinction.”

The trigger? Extreme heat given off during the formation of sills.

“Heat from sills exposed untapped, gas-rich sediments to contact metamorphism [the process in which rock minerals and texture are changed by exposure to heat and pressure], thus liberating the massive greenhouse gas volumes needed to drive extinction,” Muirhead says. “Our model links the onset of extinction with the initial pulse of sill emplacement. It represents a critical juncture in the evolution of life on Earth.”

There are two ways that magma forms igneous rock. One way is extrusion, in which magma erupts through volcanic craters and cracks in the Earth’s surface; the other is intrusion, whereby magma forces itself between or through existing formations of rock, without reaching the surface. Common types of intrusion are sills, dykes and batholiths.

Sills in Siberia’s Tunguska Basin, where Muirhead’s team carries out most of its research, likely pushed their way through limestone, coal, clastic rocks and evaporates. The mixture of hot, molten rock and hydrocarbon-bearing coals is thought to have set the stage for massive greenhouse gas release and global-scale climate change.

“Sediment composition and the amount of hydrocarbons [petroleum and natural gas] available within these sediments help us understand whether or not an LIP can trigger a mass extinction,” says Burgess, adding that his team’s model may apply to other extinction events coinciding with LIPs. “Mass extinction can take 10,000 years or less — the blink of an eye, by geological standards — but its effects on the evolutionary trajectory of life are still observable today.”

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Journal Reference:S. D. Burgess, J. D. Muirhead, S. A. Bowring. Initial pulse of Siberian Traps sills as the trigger of the end-Permian mass extinction. Nature Communications, 2017; 8 (1) DOI: 10.1038/s41467-017-00083-9
Citation:Syracuse University. “What caused the world’s greatest extinction?.” ScienceDaily. ScienceDaily, 31 July 2017. <www.sciencedaily.com/releases/2017/07/170731090834.htm>.