Arenysuchus gascabadiolorum: el cocodriloide más antiguo de Europa

Arenysuchus gascabadiolorum

Investigadores del grupo Aragosaurus-IUCA de la Universidad de Zaragoza (UNIZAR) han descrito un nuevo cocodriloide fósil llamado Arenysuchus gascabadiolorum, el más antiguo de Europa y el segundo más antiguo del mundo. El trabajo, que acaba de ser publicado en la revista PloS ONE, señala que se trataría de un cocodriloide de pequeño tamaño, con una longitud que oscilaría entre 1 y 1,5 metros y con un aspecto y un modo de vida muy similares al de los cocodrilos actuales.

Arenysuchus pertenece al grupo de los "cocodrilos verdaderos", en el que se incluyen todas las especies actuales de cocodrilos (familia Crocodylidae), aligátores y caimanes (familia Alligatoridae) y gaviales (familia Gavialidae), así como muchas formas extintas.

Una de las aportaciones más novedosas y reseñables de este descubrimiento es que Arenysuchus sería el cocodriloide más antiguo de Europa, y el segundo más antiguo del mundo junto a la especie norteamericana Prodiplocynodon langi, de aproximadamente la misma edad que Arenysuchus. 

El fósil de Arenysuchus se ha encontrado en rocas de hace unos 65 millones de años, unos pocos cientos de miles de años antes de que un meteorito marcara la extinción de los dinosaurios. La antigüedad de Arenysuchus abre una nueva vía en la investigación sobre el origen y la evolución de los cocodrilos modernos, que podría significar el origen europeo para la familia Crocodylidae, a pesar de que en la actualidad no vive ningún representante en Europa.

Otro aspecto reseñable es la importancia paleobiogeográfica del descubrimiento. Hace 65 millones de años Europa era un archipiélago compuesto por grandes islas que se suponía impedían la dispersión de los animales continentales. Los cocodrilos, a pesar de su modo de vida ligado al agua, son animales terrestres, por lo que salvo algunas excepciones tienen dificultades para nadar en grandes masas de agua marina. Cuando vivía Arenysuchus, el Atlántico Norte estaba formado, por lo que tradicionalmente se consideraba que Europa era una serie de islas infranqueables donde las faunas evolucionaban de forma endémica.

Sin embargo, Arenysuchus se encuentra estrechamente relacionado con cocodrilos norteamericanos de su misma edad por lo que la conclusión es inmediata: había migraciones de los cocodrilos hace 65 millones de años entre las islas europeas y Norteamérica. El paso lo tendrían por las actuales tierras heladas del Polo Norte. 

Posiblemente esto sucedía en los momentos de bajada del nivel del mar, en los que estos animales se aprovechaban de los puentes de tierra y la poca profundidad para pasar entre islas. Además de los cocodrilos, estos pasos de tierra los aprovecharían mamíferos, dinosaurios y otros reptiles del final del Cretácico.






Fuente Original: Noticias de Ciencia

3D Galaxies – Coming Straight On For You

As we’ve recently learned, the ATLAS3D project was able to study 260 individual galaxies and do some very amazing things. By imaging in both red and blue shift, astronomers were able to take stellar measurements and give us a clear picture of galaxy rotation. But looking at a computer generated image gives a picture just like you reading the text in this article – no dimension. By superimposing the velocity of the stars over the plane of the image, a new breakthrough in simulation can be made. And it’s coming straight on for you…

We understand images of grand spirals and their sweeping arms. We marvel at photos of dust-lanes in those far off distant island universes. Even the motley elliptical galaxy gives us a sense of shape. But what would happen if we could take a different angle at what we see? How would galaxy mergers affect rotation? When galaxies collide, it sparks new starbirth… But how would it look?

“Young galaxies seem to have lots of gas that hasn’t yet been turned into burning stars — and they spin fast, so they look like the poster-child galaxy with spiral arms and dust lanes.” says the ATLAS team. “By telling us how fast stars in a galaxy rotate around their galaxy’s centre, the ATLAS3D result changes our understanding of galaxies and how they evolve over time.”

By studying these new images and techniques, astronomers will be able to tell us more about galaxies that have survived a crash and lived to spin. It could very well be that mergers of this type don’t affect orderly rotation and overall symmetry. The ATLAS3D team has already prepared computer simulations and performed more telescope observations to test this idea. And it’s coming straight on… Straight on for you.

Original Story Source: University of Toronto. Animation: NASA/SAO/CXC/D.Berry Images: X-ray: NASA/CXC/UMass/D.Wang et al., UV: NASA/GSFC/UIT, Optical: NASA/HST/D.Wang et al.

Provided by Universe Today

A Glitch in Pulsar J1718-3718

Pulsar diagram (© Mark Garlick)

Pulsars are noted as being some of the universe’s best clocks. Their highly magnetized nature gives rise to beams of high energy radiation that sweep out across the universe. If these beams pass Earth, they can rival atomic clocks in their precision. So precise are these timings, that the first extrasolar planet was discovered through the effects it had on this heartbeat. But in September of 2007, pulsar J1718-3719 appears to have had a seizure.

These disjunctions aren’t unprecedented. While not exactly frequent, such “glitches” have been noted previously in other pulsars and magnetars. These glitches are often displayed as a sudden change in the period of the pulsar suddenly drops and then slowly relaxes back to the pre-glitch value at a characteristic rate dependent on the previous value as well as how large the jump was. Behavior like this has been seen in other pulsars including PSR B2334+61 and PSR 1048-5397.

The size of a glitch is measured as a ratio of the change in speed due to the glitch as compared to that of the pre-glitch speed. For past glitches, these have generally been changes that are around a hundredth of a percent. While this may not sound like a large change, the stars on which they act are exceptionally dense neutron stars. As such, even a small change in rotational energy means a large amount of energy involved.

Previously, the largest known glitch was 20.5 x 10^-6 for PSR B2334+61. The new glitch in PSR J1718-3718 beats this record with a frequency change of 33.25 x 10^-6. Aside from being a record setter, this new glitch does not appear to be following the trend of returning to previous values. The changed period persisted for the 700 days astronomers at the Australia Telescope National Facility observed it. Pulsars tend to have a slow braking applied to them due to a difference between their rotational axes and their magnetic ones. This too generally returns to a standard value for a given pulsar following a glitch, but PSR J1718-3718 defied expectations here as well, having a persistently higher braking effect which has continued to increase.

Currently, astronomers know precious little about the effects which may cause these glitches. There is no evidence to suggest that the phenomenon is something external to the body itself. Instead, astronomers suspect that there are occasional alignments of the stars internal superfluid core which rotates more quickly, with the star’s crust that cause the two to occasionally lock together. Models of neutron stars have had some success at reproducing this odd behavior, but none have suggested an event like PSR J1718-3718. Instead, the authors of the recent study suggest that this may have been caused by a fracturing of the crust of the neutron star or some yet unknown internal reaction. The possibilities currently are not well constrained but studying future events like these will help astronomers refine their models.

Provided by Universe Today

Magnetic Ropes Skip To Solar Storms

On the left, SDO AIA image at the wavelength of 131 angstroms observing the Sun’s atmosphere at a temperature of about ten million degrees. The magnetic rope is seen as the thick looped structure extending above the edge of the Sun. On the right, SDO AIA image at wavelength 171 angstroms observing the corona at a temperature of about one million degrees, showing surrounding cool magnetic field lines are pushed away by the intruding magnetic rope seen on the left. Both images are taken almost simultaneously (within three seconds of each other) at 03:41 UT. (Credit: NASA and George Mason University).

It is our current understanding that the Sun’s magnetic fields and field lines are the cause of solar storms. However, there is no solid evidence as to what form magnetic field lines may take ahead of an energetic outbreak. We know there can be loops connected to the surface – but normally they take the sting off an eruption, rather than cause one. Thanks to a discovery made by associate professor Jie Zhang and his graduate student Xin Cheng using images from the NASA Solar Dynamics Observatory (SDO) spacecraft, we’re shedding a little light on a solar mystery.

An event called a magnetic rope is assumed to be the progenitor of solar storms – but its existence was far from certain. The phenomena may consist of many magnetic field lines wrapping around a center axis – possibly twisting around each other – and producing an electric current. The current might then be able to generate enough electromagnetic force to overpower the withholding magnetic field lines and cause the rope to move outward at speeds we so far haven’t been able to document… Until now.

Thanks to the images taken by the Atmospheric Imaging Assembly (AIA) telescope on board the SDO, Zhang was able to isolate an area of the Sun where a magnetic rope was forming. What the images provided was a unique look at an active region ahead of an eruption. Revealed was a long and low-lying channel which produces temperatures up to 10 million degrees – and continues heating. When it reaches a critical point this “hot channel” reveals a never before seen feature unlike the surrounding magnetic field lines… possibly the theoretical magnetic rope.

“The magnetic rope triggers a solar eruption. Scientists have been debating whether or not this magnetic rope exists before a solar eruption. I believe that the result of this excellent observation helps finally solve this controversial issue,” says Zhang.

As we’re all aware, it would be a boost to understand and predict solar storms. While our Earth’s “magnetic shield” protects us from the majority of direct exposure, we have satellites, astronauts and terrestrially-based power sources which could benefit from an early warning scenario.

“Understanding the eruption process of these storms will definitely help us better predict them,” says Zhang. “We cannot prevent solar storms, just like we cannot prevent earthquakes or volcanoes. But the development of prediction capacity can help mitigate adverse effects. For instance, satellite operators can power-down key systems to prevent the possible damage to the systems.”

Provided by Universe Today - MSNBC

Astronomers Discover a Neutron Star Illuminated by an X-Ray Flare & 4 new Items

The European Space Agencies' XMM-Newton space observatory has watched a faint star flare up at X-ray wavelengths to almost 10,000 times its normal brightness. Astronomers believe the outburst was caused by the star trying to eat a giant clump of matter much larger than the neutron star and came from its enormous blue supergiant companion star.

Astronomers Discover a Neutron Star Illuminated by an X-Ray Flare The European Space Agencies' XMM-Newton space observatory has watched a faint star flare up at X-ray wavelengths to almost 10,000 times its normal brightness. Astronomers believe the outburst was caused by the star trying to eat a giant clump of...

"Eerie Voices of Saturn" - Audio Signals Differ at Its North and South Hemispheres Data from NASA's Cassini spacecraft show that the variation in radio waves controlled by the planet's rotation is different in the northern and southern hemispheres. Moreover, the northern and southern rotational variations also appear to change with the Saturnian seasons,...

Cygnus X-1 --A Black Hole: Harvard-Smithsonian Astronomers Prove Stephen Hawking Was Wrong Several thousand light-years from Earth, near the "heart" of Cygnus, the swan, two stars are locked in their gravitational destiny. One star is a blue supergiant, known as HDE 226868 --about 30 times as massive as the Sun and 400,000...

Image of the Day: The Virgo Cluster of Galaxies Image of the Day: The Virgo Cluster of Galaxies What mysteries lurk here! This deep image of the Virgo Cluster comprises approximately 1300 to 2000 member galaxies, forming the heart of the larger Local Supercluster, of which the Local Group...

Weirder, Weird Weather --"La Niña, El Niño, La Nada" Some recent news reports have attributed the nation's record snowfall, killer tornadoes, and devastating floods phenomenon to an extreme "La Niña," a band of cold water stretching across the Pacific Ocean with global repercussions for climate and weather. "La Niña... Provided by The Daily Galaxy

Space & Earth Updates - Astronomers find universe's most distant quasar (w/ video) & more

Enlarge

This artist’s impression shows how ULAS J1120+0641, a very distant quasar powered by a black hole with a mass two billion times that of the Sun, may have looked. This quasar is the most distant yet found and is seen as it was just 770 million years after the Big Bang. This object is by far the brightest object yet discovered in the early Universe. Credit: ESO/M. Kornmesser

A team of European astronomers has used ESO’s Very Large Telescope and a host of other telescopes to discover and study the most distant quasar found to date. This brilliant beacon, powered by a black hole with a mass two billion times that of the Sun, is by far the brightest object yet discovered in the early Universe. The results will appear in the 30 June 2011 issue of the journal Nature.

For more information about Updates, Click on the titles:

Archaeological dig uncovers artifacts 

Scientific equipment belonging to an Enlightenment figure has been found in an archaeological dig at the University.

Prehistoric BBQ has bone marrow and aurochs on the menu 

(PhysOrg.com) -- In the July issue of the Journal of Archaeological Science, researchers reveal the prehistoric remains of a BBQ in the valley of the River Tjonger in the Netherlands that took place over 7,700 years ago.

Finding showing human ancestor older than previously thought offers new insights into evolution 

(PhysOrg.com) -- Modern humans never co-existed with Homo erectus -- a finding counter to previous hypotheses of human evolution—new excavations in Indonesia and dating analyses show. The research, reported in the journal PLoS One, offers new insights into the nature of human evolution, suggesting a different role for Homo erectus than had been previously thought.

The math of the Rubik's cube 

Last August, 30 years after the Rubik’s cube first appeared, an international team of researchers proved that no matter how scrambled a cube got, it could be solved in no more than 20 moves. Although the researchers used some clever tricks to avoid evaluating all 43 quintillion of the cube’s possible starting positions, their proof still relied on the equivalent of 35 years’ worth of number crunching on a good modern computer.

New fossils demonstrate that powerful eyes evolved in a twinkling (w/ video) 

Palaeontologists have uncovered half-a-billion-year-old fossils demonstrating that primitive animals had excellent vision.

Moving microscopic vision into another new dimension 

Scientists who pioneered a revolutionary 3-D microscope technique are now describing an extension of that technology into a new dimension that promises sweeping applications in medicine, biological research, and development of new electronic devices. Their reports on so-called 4-D scanning ultrafast electron microscopy, and a related technique, appear in two papers in the Journal of the American Chemical Society.

Printing solar cells 

Australian researchers have invented nanotech solar cells that are thin, flexible and use 1/100th the materials of conventional solar cells.

Magnetic control of anomalous hall effect induced by spin chirality 

Institute for Solid State Physics, the University of Tokyo and RIKEN announced that researchers from both institutes succeeded in the magnetic control of anomalous Hall effect (AHE) induced by spin chirality. Details were published in Physical Review Letters.

A remarkable step toward next-generation energy-conservation 

Tohoku University, Osaka University and Japan Science and Technology Agency (JST) announced that they succeeded in directly observing electron spins in a topological insulator. The work has been published in Physical Review Letters with the lead author Seigo Souma, Assistant Professor of Tohoku University.

Northwestern research team turns theory of static electricity on its head 

(PhysOrg.com) -- Bartosz Grzybowski, a physical chemist at Northwestern University, and his team of colleagues offer evidence in a paper published in Science, that shows that what scientists have believed to be true about the causes behind the creation of static electricity, is wrong. Instead of one object winding up with more or less electrons as a result of rubbing together, they claim, there is an actual transfer of slight amounts of actual material.

How do electrons become entangled? 

(PhysOrg.com) -- A Princeton researcher and his international collaborators have used lasers to peek into the complex relationship between a single electron and its environment, a breakthrough that could aid the development of quantum computers.

At small scales, tug-of-war between electrons can lead to magnetism under surprising circumstances 

(PhysOrg.com) -- At the smallest scales, magnetism may not work quite the way scientists expected, according to a recent paper in Physical Review Letters by Rafal Oszwaldowski and Igor Zutic of the University at Buffalo and Andre Petukhov of the South Dakota School of Mines and Technology.

Physicists seek to quantify macroscopic quantum states 

(PhysOrg.com) -- "Scientists have been interested in generating and observing macroscopic quantum superpositions in order to test quantum mechanics at the macroscopic scale," physicist Hyunseok Jeong of Seoul National University in Seoul, South Korea, told PhysOrg.com. "There have been many papers in which the authors claim to have generated mesoscopic or macroscopic superpositions, often called 'Schrodinger cat states.' However, quoting A. J. Leggett in 2002, a question from the theoretical side is ‘What is the correct measure of "Schrodinger's-cattiness"?' It has been considered difficult to answer this question with a general measure, and the answer has remained to be 'very much a matter of personal taste,' quoting Leggett again. Our work now provides scientists with a theoretical tool to quantify and compare different types of quantum superpositions. This can be a step toward rigorous tests of quantum mechanics in a macroscopic limit."

Towns near NM fire, nuclear lab wary of smoke 

(AP) -- Residents downwind of a wildfire that is threatening the nation's premier nuclear-weapons laboratory are worried about the potential of a radioactive smoke plume if the flames reach thousands of barrels of waste stored in above-ground tents.

NASA aircraft to study air pollution 

(PhysOrg.com) -- Two NASA research aircraft will fly over the Baltimore-Washington area of northeastern Maryland through July as part of a mission to enhance the measurement of ground-level air quality from space.

European research effort improves understanding of impacts of aerosols on climate 

Atmospheric aerosol particles (otherwise known as Particulate Matter) have been masking the true rate of greenhouse gas induced global warming during the industrial period. New investigations show that the aerosol cooling effect will be strongly reduced by 2030, as air pollution abatements are implemented worldwide and the presently available advanced control technologies are utilized. These actions would increase the global mean temperature by ca. 1 degree Celsius. This is one of the main research outcomes of the recently concluded EU EUCAARI (European Integrated project on Aerosol Cloud Climate and Air Quality Interaction) project.

Airplane deployed to monitor air over NM fire 

(AP) -- The government sent a plane equipped with radiation monitors over the Los Alamos nuclear laboratory Wednesday as a 110-square-mile wildfire burned at its doorstep, putting thousands of scientific experiments on hold for days.

Experts warn epic weather ravaging US could worsen 

Epic floods, massive wildfires, drought and the deadliest tornado season in 60 years are ravaging the United States, with scientists warning that climate change will bring even more extreme weather.

First ARTEMIS spacecraft successfully enters lunar orbit 

(PhysOrg.com) -- The first of two ARTEMIS ("Acceleration, Reconnection, Turbulence and Electrodynamics of the Moon’s Interaction with the Sun") spacecraft is now in its lunar orbit.

GOES-13 satellite movie shows how Tropical Storm Arlene formed 

Have you ever seen a low pressure area develop into a full-fledged tropical storm? The GOES-13 satellite has and now you can see it in a new animation released today from NASA and NOAA.

Recycling: A new source of indispensible 'rare earth' materials mined mainly in China 

That axiom of sustainability -- "recycle and reuse" -- could help ease concerns about a reliable supply of substances, indispensible for a modern technological society, that are produced almost exclusively in the Peoples' Republic of China. That's the conclusion of a study on these so-called "rare earth" elements in the ACS journal Environmental Science & Technology.

Hawaiian hotspot variability attributed to small-scale convection 

Small scale convection at the base of the Pacific plate has been simulated in a model of mantle plume dynamics, enabling reasearchers to explain the complex set of observations at the Hawaiian hotspot, according to a new study posted online in the June 26th edition of Nature Geoscience.

Urban rail reduces carbon monoxide air pollution 

The opening of a major urban rail system in Taiwan caused a meaningful reduction in air pollution, according to a forthcoming study by two professors at the University of California, Merced.

3D galaxies -- coming straight on for you 

As we've recently learned, the ATLAS3D project was able to study 260 individual galaxies and do some very amazing things. By imaging in both red and blue shift, astronomers were able to take stellar measurements and give us a clear picture of galaxy rotation. But looking at a computer generated image gives a picture just like you reading the text in this article – no dimension. By superimposing the velocity of the stars over the plane of the image, a new breakthrough in simulation can be made. And it’s coming straight on for you…

Honing in on landing site for new Mars Rover 

NASA's new Mars probe, a $2.5 billion, nuclear-powered rover the size of a small car, is at the Florida launch site being prepared for its nine-month journey to the red planet, with one key issue still unresolved -- where to land.

GOES satellites see ash still spewing from Chilean volcano 

The Puyehue-Cordón volcano in Chile continues to spew ash that is still disrupting travel as far as Australia and New Zealand this week. A new animation of satellite imagery just released from the NASA/NOAA GOES Project shows the ash spewing from the volcano.

Scientists study earthquake triggers in Pacific ocean 

(PhysOrg.com) -- New samples of rock and sediment from the depths of the eastern Pacific Ocean may help explain the cause of large, destructive earthquakes similar to the Tohoku Earthquake that struck Japan in mid-March.

Cutting fishing could buy time for coral reefs 

Stopping people fishing around Caribbean coral reefs by designating them legally protected marine reserves could help some of them survive the effects of a changing climate by more than 50 years.

A glitch in pulsar J1718-3718 

Pulsars are noted as being some of the universe’s best clocks. Their highly magnetized nature gives rise to beams of high energy radiation that sweep out across the universe. If these beams pass Earth, they can rival atomic clocks in their precision. So precise are these timings, that the first extrasolar planet was discovered through the effects it had on this heartbeat. But in September of 2007, pulsar J1718-3719 appears to have had a seizure.

Astronomers find universe's most distant quasar (w/ video) 

(PhysOrg.com) -- A team of European astronomers has used ESO’s Very Large Telescope and a host of other telescopes to discover and study the most distant quasar found to date. This brilliant beacon, powered by a black hole with a mass two billion times that of the Sun, is by far the brightest object yet discovered in the early Universe. The results will appear in the 30 June 2011 issue of the journal Nature.

'Odd couple' binary makes dual gamma-ray flares 

(PhysOrg.com) -- In December 2010, a pair of mismatched stars in the southern constellation Crux whisked past each other at a distance closer than Venus orbits the sun. The system possesses a so-far unique blend of a hot and massive star with a compact fast-spinning pulsar. The pair's closest encounters occur every 3.4 years and each is marked by a sharp increase in gamma rays, the most extreme form of light.

Provided by PhysOrg.com