Formation of sedimentary layers of white clay, Tamilnadu, India

Fossil site for wood fossils, Tamilnadu, India

Fossil site in Kerala, 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

WFS News: Chicxulub asteroid impact cooled Earth’s climate more than previously thought

November 5th, 2017 Riffin

@WFS,World Fossil Society,Riffin T Sajeev,Russel T Sajeev

The Chicxulub asteroid impact that wiped out the dinosaurs likely released far more climate-altering sulfur gas into the atmosphere than originally thought, according to new research.

A new study makes a more refined estimate of how much sulfur and carbon dioxide gas were ejected into Earth’s atmosphere from vaporized rocks immediately after the Chicxulub event. The study’s authors estimate more than three times as much sulfur may have entered the air compared to what previous models assumed, implying the ensuing period of cool weather may have been colder than previously thought.

The new study lends support to the hypothesis that the impact played a significant role in the Cretaceous-Paleogene extinction event that eradicated nearly three-quarters of Earth’s plant and animal species, according to Joanna Morgan, a geophysicist at Imperial College London in the United Kingdom and co-author of the new study published in Geophysical Research Letters, a journal of the American Geophysical Union.

“Many climate models can’t currently capture all of the consequences of the Chicxulub impact due to uncertainty in how much gas was initially released,” Morgan said. “We wanted to revisit this significant event and refine our collision model to better capture its immediate effects on the atmosphere.”

The Chicxulub Crater was created by an asteroid that struck the Earth about 66 million years ago

The Chicxulub Crater was created by an asteroid that struck the Earth about 66 million years ago

The new findings could ultimately help scientists better understand how Earth’s climate radically changed in the aftermath of the asteroid collision, according to Georg Feulner, a climate scientist at the Potsdam Institute for Climate Impact Research in Potsdam, Germany who was not involved with the new research. The research could help give new insights into how Earth’s climate and ecosystem can significantly change due to impact events, he said.

“The key finding of the study is that they get a larger amount of sulfur and a smaller amount of carbon dioxide ejected than in other studies,” he said. “These improved estimates have big implications for the climactic consequences of the impact, which could have been even more dramatic than what previous studies have found.”

A titanic collision

The Chicxulub impact occurred 66 million years ago when an asteroid approximately 12 kilometers (7 miles) wide slammed into Earth. The collision took place near what is now the Yucatán peninsula in the Gulf of Mexico. The asteroid is often cited as a potential cause of the Cretaceous-Paleogene extinction event, a mass extinction that erased up to 75 percent of all plant and animal species, including the dinosaurs.

The asteroid collision had global consequences because it threw massive amounts of dust, sulfur and carbon dioxide into the atmosphere. The dust and sulfur formed a cloud that reflected sunlight and dramatically reduced Earth’s temperature. Based on earlier estimates of the amount of sulfur and carbon dioxide released by the impact, a recent study published in Geophysical Research Letters showed Earth’s average surface air temperature may have dropped by as much as 26 degrees Celsius (47 degrees Fahrenheit) and that sub-freezing temperatures persisted for at least three years after the impact.

In the new research, the authors used a computer code that simulates the pressure of the shock waves created by the impact to estimate the amounts of gases released in different impact scenarios. They changed variables such as the angle of the impact and the composition of the vaporized rocks to reduce the uncertainty of their calculations.

The new results show the impact likely released approximately 325 gigatons of sulfur and 425 gigatons of carbon dioxide into the atmosphere, more than 10 times global human emissions of carbon dioxide in 2014. In contrast, the previous study in Geophysical Research Letters that modeled Earth’s climate after the collision had assumed 100 gigatons of sulfur and 1,400 gigatons of carbon dioxide were ejected as a result of the impact.

Improving the impact model

The new study’s methods stand out because they ensured only gases that were ejected upwards with a minimum velocity of 1 kilometer per second (2,200 miles per hour) were included in the calculations. Gases ejected at slower speeds didn’t reach a high enough altitude to stay in the atmosphere and influence the climate, according to Natalia Artemieva, a senior scientist at the Planetary Science Institute in Tucson, Arizona and co-author of the new study.

Older models of the impact didn’t have as much computing power and were forced to assume all the ejected gas entered the atmosphere, limiting their accuracy, Artemieva said.

The study authors also based their model on updated estimates of the impact’s angle. An older study assumed the asteroid hit the surface at an angle of 90 degrees, but newer research shows the asteroid hit at an angle of approximately 60 degrees. Using this revised angle of impact led to a larger amount of sulfur being ejected into the atmosphere, Morgan said.

The study’s authors did not model how much cooler Earth would have been as a result of their revised estimates of how much gas was ejected. Judging from the cooling seen in the previous study, which assumed a smaller amount of sulfur was released by the impact, the release of so much sulfur gas likely played a key role in the extinction event. The sulfur gas would have blocked out a significant amount of sunlight, likely leading to years of extremely cold weather potentially colder than the previous study found. The lack of sunlight and changes in ocean circulation would have devastated Earth’s plant life and marine biosphere, according to Feulner.

The release of carbon dioxide likely led to some long-term climate warming, but its influence was minor compared to the cooling effect of the sulfur cloud, Feulner said.

Along with gaining a better understand of the Chicxulub impact, researchers can also use the new study’s methods to estimate the amount of gas released during other large impacts in Earth’s history. For example, the authors calculated the Ries crater located in Bavaria, Germany was formed by an impact that ejected 1.3 gigatons of carbon dioxide into the atmosphere. This amount of gas likely had little effect on Earth’s climate, but the idea could be applied to help understand the climactic effects of larger impacts.

Natalia Artemieva, Joanna Morgan. Quantifying the Release of Climate-Active Gases by Large Meteorite Impacts With a Case Study of Chicxulub. Geophysical Research Letters, 2017; DOI: 10.1002/2017GL074879 

American Geophysical Union. “Dinosaur-killing asteroid impact cooled Earth’s climate more than previously thought.” ScienceDaily. ScienceDaily, 31 October 2017. <www.sciencedaily.com/releases/2017/10/171031111446.htm>.

@WFS,World Fossil Society,Riffin T Sajeev,Russel T Sajeev

WFS News: why the largest are not always the fastest

November 4th, 2017 Riffin

@WFS,World Fossil Society,Riffin T Sajeev,Russel T Sajeev

No other animal on land is faster than a cheetah — the elephant is indeed larger, but slower. For small to medium-sized animals, larger also means faster, but for really large animals, when it comes to speed, everything goes downhill again. For the first time, it is now possible to describe how this parabola-like relationship between body size and speed comes about. A research team under the direction of the German Centre for Integrative Biodiversity Research (iDiv) and the Friedrich Schiller University Jena (Germany) have managed to do so thanks to a new mathematical model, and also published their findings in the journal Nature Ecology and Evolution.

A beetle is slower than a mouse, which is slower than a rabbit, which is slower than a cheetah… which is slower than an elephant? No! No other animal on land is faster than a cheetah — the elephant is indeed larger, but slower. For small to medium-sized animals, larger also means faster, but for really large animals, when it comes to speed, everything goes downhill again. For the first time, it is now possible to describe how this parabola-like relationship between body size and speed comes about.

There is a parabola-like relationship between the body mass of animals and the maximum speed they can reach. For the first time, researchers are able to describe how this comes about, thanks to a simple mathematical model. Credit: Copyright Myriam Hirt

There is a parabola-like relationship between the body mass of animals and the maximum speed they can reach. For the first time, researchers are able to describe how this comes about, thanks to a simple mathematical model.Credit: Copyright Myriam Hirt

The model is amazingly simple: The only information that it must be ‘fed’ with is the weight of a particular animal as well as the medium it moves in, so either land, air or water. On this basis alone, it calculates the maximum speed that an animal can reach with almost 90% accuracy. “The best feature of our model is that it is universally applicable,” says the lead author of the study, Myriam Hirt of the iDiv research centre and the University of Jena. “It can be performed for all body sizes of animals, from mites to blue whales, with all means of locomotion, from running and swimming to flying, and can be applied in all habitats.” Moreover, the model is by no means limited to animal species that currently exist, but can be applied equally well to extinct species.

Tyrannosaurus reached a speed of only 17 miles/hour

“To test whether we can use our model to calculate the maximum speed of animals that are already extinct, we have applied it to dinosaur species, whose speed has up to now been simulated using highly complex biomechanical processes,” explains Hirt. The result is that the simple model delivered results for Triceratops, Tyrannosaurus, Brachiosaurus and others that matched those from complex simulations — and were not exactly record-breaking for Tyrannosaurus, who reached a speed of only 27 km/h (17 mi/h). “This means that in future, our model will enable us to estimate, in a very simple way, how fast other extinct animals were able to run,” says the scientist.

Mass has to overcome inertia

Two assumptions are the basis of the model. The first assumption is related on the fact that animals reach their maximum speeds during comparatively short sprints, and not while running over long distances. Unlike running over longer distances, where the body constantly resupplies the muscles with energy (aerobic metabolism), sprinting uses energy that is stored in the muscles themselves but which is exhausted relatively quickly (anaerobic metabolism). It seems logical enough: the larger the animal, the more muscle it has — and thus the faster it can sprint. However, Newton’s laws of motion also apply in the animal kingdom, we know mass has to overcome inertia, and so a five-tonne African elephant simply cannot start moving as quickly as a 2.5-gramme Etruscan shrew. By the time large animals such as the elephant get up to full speed while sprinting, their rapidly available energy reserves also soon run out. Taken together, these two assumptions result in the previously mentioned curve: A beetle is slower than a mouse, which is slower than a rabbit, which is slower than a cheetah — which is faster than an elephant.

@WFS,World Fossil Society,Riffin T Sajeev,Russel T Sajeev

  1. Myriam R. Hirt, Walter Jetz, Björn C. Rall, Ulrich Brose. A general scaling law reveals why the largest animals are not the fastest. Nature Ecology & Evolution, 2017; DOI: 10.1038/s41559-017-0241-4
  2. Friedrich Schiller University Jena. “Why Tyrannosaurus was a slow runner and why the largest are not always the fastest.” ScienceDaily. ScienceDaily, 17 July 2017.

WFS News: mysterious ancient cone-shaped sea creatures(Hyoliths ) are Palaeozoic lophophorates

November 3rd, 2017 Riffin

@WFS,World Fossil Society,Riffin T Sajeev,Russel T Sajeev

One branch on the tree of life is a bit more crowded today. A team of scientists led by 20-year-old University of Toronto (U of T) undergraduate student Joseph Moysiuk has finally determined what a bizarre group of extinct cone-shaped animals actually are.

Known as hyoliths, these marine creatures evolved over 530 million years ago during the Cambrian period and are among the first animals known to have produced mineralized external skeletons.

Long believed to belong to the same family as snails, squid and other molluscs, a study published today in the scientific journal Nature shows that hyoliths are instead more closely related to brachiopods — a group of animals which has a rich fossil record, although few living species remain today.

Brachiopods have a soft body enclosed between upper and lower shells (valves), unlike the left and right arrangement of valves in bivalve molluscs. Brachiopods open their valves at the front when feeding, but otherwise keep them closed to protect their feeding apparatus and other body parts.

Although the skeletal remains of hyoliths are abundant in the fossil record, key diagnostic aspects of their soft-anatomy remained critically absent until now.

“Our most important and surprising discovery is the hyolith feeding structure, which is a row of flexible tentacles extending away from the mouth, contained within the cavity between the lower conical shell and upper cap-like shell,” said Moysiuk. “Only one group of living animals — the brachiopods — has a comparable feeding structure enclosed by a pair of valves. This finding demonstrates that brachiopods, and not molluscs, are the closest surviving relatives of hyoliths.

“It suggests that these hyoliths fed on organic material suspended in water as living brachiopods do today, sweeping food into their mouths with their tentacles,” Moysiuk said.

Moysiuk, who studies Earth sciences and ecology & evolutionary biology, completed this project as part of the Research Opportunity Program at U of T, a special undergraduate research program in the Faculty of Arts & Science.

The distinctive appearance and structure of the hyolith skeleton has obstructed previous attempts to classify these animals. All hyoliths had an elongated, bilaterally symmetrical cone-shaped shell and a smaller cap-like shell which covered the opening of the conical shell (known as an operculum). Some species also bore a pair of rigid, curved spines (known as helens) that protruded from between the conical shell and operculum — structures with no equivalents in any other group of animals.

Examination of the orientation of the helens in multiple hyolith specimens from the Burgess Shale suggests that these spines may have been used like stilts to lift the body of the animal above the sediment, elevating the feeding apparatus to enhance feeding.

Moysiuk and coauthors Martin Smith at Durham University in the United Kingdom, and Jean-Bernard Caron at the Royal Ontario Museum (ROM) and U of T were able to complete the descriptions based mainly on newly discovered fossils from the renowned Cambrian Burgess Shale in British Columbia.

“Burgess Shale fossils are exceptional because they show preservation of soft tissues which are not usually preserved in normal conditions,” said Caron, Moysiuk’s research supervisor, who is the senior curator of invertebrate palaeontology at the ROM and an associate professor in U of T’s Departments of Earth Sciences and Ecology & Evolutionary Biology.

“Although a molluscan affinity was proposed by some authors, this hypothesis remained based on insufficient evidence. Hyoliths became an orphaned branch on the tree of life, an embarrassment to paleontologists. Our most recent field discoveries were key in finally cracking their story, around 175 years after the first description of a hyolith.”

Dorsal view of specimens, anterior to the top. Detail and whole specimen. ROM59943.1, H. carinatus from Stanley Glacier (Kootenay National Park, B.C.), showing partially extended lophophore, with tentacles beyond the operculum margin. Credit: © Royal Ontario Museum

Dorsal view of specimens, anterior to the top. Detail and whole specimen. ROM59943.1, H. carinatus from Stanley Glacier (Kootenay National Park, B.C.), showing partially extended lophophore, with tentacles beyond the operculum margin.
Credit: © Royal Ontario Museum

Caron led recent fieldwork activities to the Burgess Shale which resulted in the discovery of many specimens that form the basis of this study. The key specimens came from recently discovered deposits near Stanley Glacier and Marble Canyon in Kootenay National Park, about 40 kilometres southeast of the original Burgess Shale site in Yoho National Park.

The Burgess Shale is one of the most important fossil deposits for studying the origin and early evolution of animals that took place during the Cambrian period, starting about 542 million years ago. Hyoliths are just one of the profusion of animal groups that characterize the fauna of the ‘Cambrian Explosion’. They became a diverse component of marine ecosystems around the globe for more than 280 million years, only to go extinct 252 million years ago, prior to the evolution of the first dinosaurs.

“Resolving the debate over the hyoliths adds to our understanding of the Cambrian Explosion, the period of rapid evolutionary development when most major animal groups emerge in the fossil record,” said Smith, who started this research at the University of Cambridge and who is now a lecturer in paleontology at Durham University. “Our study reiterates the importance of soft tissue preservation from Burgess Shale-type deposits in illuminating the evolutionary history of creatures about which we still know very little.”

The Burgess Shale, from which the specimens were recovered from several locations, is part of the Canadian Rocky Mountain Parks World Heritage Site. It is one of the most important fossil deposits for understanding the origin and early evolution of animals that took place during the Cambrian Explosion starting about 542 million years ago.

Parks Canada protects this globally significant site, and supports peer-reviewed scientific research that continues to enhance our understanding of these rich paleontological deposits. This discovery adds another element to the dramatic story of early animal evolution that Parks Canada guides share enthusiastically with hundreds of park visitors every year.

Funding for the research was provided primarily by the Royal Ontario Museum and a Natural Sciences and Engineering Research Council of Canada Discovery Grant to Caron.

Joseph Moysiuk, Martin R. Smith, Jean-Bernard Caron. Hyoliths are Palaeozoic lophophorates. Nature, 2017; DOI: 10.1038/nature20804

  • University of Toronto. “Paleontologists classify mysterious ancient cone-shaped sea creatures.” ScienceDaily. ScienceDaily, 11 January 2017. <www.sciencedaily.com/releases/2017/01/170111132815.htm>.
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WFS News: Did dark matter kill the dinosaurs?

November 2nd, 2017 Riffin

@WFS,World Fossil Society,Riffin T Sajeev,Russel T Sajeev

More than 99% of all the species that have ever lived on our planet are now extinct, and while the majority of these die-offs can be attributed to competition or failure to adapt, many perished during dramatic cataclysmic events. The fossil record shows us that these mass extinctions seem to occur periodically in cycles of approximately 26 to 30 million years—which, interestingly, is similar to the amount of time it takes our sun to bob up and down through the galactic disc and cross the center line of the Milky Way.

This region, known as the galactic plane, is crowded with clouds of dust and gas which could disturb space debris within our solar system and send some hurtling towards our planet, which would fit in with some of the mass extinctions. However, according to new research, there could be something else at play: dark matter.

As described in Monthly Notices of the Royal Astronomical Society, passing through concentrated regions of this elusive, invisible stuff could also send comets on an Earth-bound collision course. Furthermore, dark matter particles could also ramp up temperatures in our planet’s core, which could affect geological systems and trigger extinction events.

Mass Extinctions On Earth

 Mass Extinctions On Earth

Our galaxy, the Milky Way, is a huge flat disk of stars, dust and gas measuring some 120,000 light-years across. The center line of this huge spinning disk, or galactic plane, is known to be concentrated with dust and gas, but also seems to be crowded with dark matter. Although we can’t directly observe this substance, scientists know it exists because it exerts gravitational effects on other objects in space. From these observations, scientists have estimated that each square light-year of the galactic plane contains around one solar mass of dark matter.

While our solar system rotates around the Milky Way, which takes around 250 million years, it also vertically oscillates through the galactic disk, passing through the galactic plane around every 30 million years or so. This correlates with the documented intervals between mass extinction events and comet impacts on Earth, which prompted scientist Michael Rampino from New York University to consider further what could be going on.

Although previous work has suggested that the concentration of dust and gas in the plane could be responsible for messing up the orbits of comets in our solar system, Rampino proposes that dark matter could also be a contributing factor. Clouds of the stuff could disturb the orbits of space debris and fling some towards Earth, causing huge collision events like the famous comet strike 66 million years ago which wiped out the dinosaurs.

Another possibility is that, as our planet passes through the plane, dark matter particles could get caught in our planet’s gravity, eventually causing them to fall towards Earth’s core and accumulate here. These particles would then begin to annihilate each other over time, creating an immense amount of heat in the core, rising its temperature by several hundred degrees Celsius. Over millions of years, this heat could travel towards the surface, triggering events such as volcanic eruptions or changes in global climate and sea level, which could wipe out a large number of species on Earth.

@WFS,World Fossil Society,Riffin T Sajeev,Russel T Sajeev

 

WFS News: Past Ocean Temperatures were colder?

November 1st, 2017 Riffin

@WFS,World Fossil Society,Riffin T Sajeev,Russel T Sajeev

A team of researchers has discovered a flaw in the way past ocean temperatures have been estimated up to now. Their findings could mean that the current period of climate change is unparalleled over the last 100 million years.

According to the methodology widely used by the scientific community, the temperature of the ocean depths and that of the surface of the polar ocean 100 million years ago were around 15 degrees higher than current readings. This approach, however, is now being challenged: ocean temperatures may in fact have remained relatively stable throughout this period, which raises serious concerns about current levels of climate change. These are the conclusions of a study conducted by a team of French researchers from the French National Center for Scientific Research (CNRS), Sorbonne University and the University of Strasbourg, and Swiss researchers from the Swiss Federal Institute of Technology in Lausanne (EPFL) and the University of Lausanne. The study has just been published in Nature Communications.

“If we are right, our study challenges decades of paleoclimate research,” says Anders Meibom, the head of EPFL’s Laboratory for Biological Geochemistry and a professor at the University of Lausanne. Meibom is categorical: “Oceans cover 70% of our planet. They play a key role in Earth’s climate. Knowing the extent to which their temperatures have varied over geological time is crucial if we are to gain a fuller understanding of how they behave and to predict the consequences of current climate change more accurately.”

The current period of climate change may be unparalleled over the last 100 million years, say researchers. Credit: © Alekss / Fotolia

The current period of climate change may be unparalleled over the last 100 million years, say researchers.Credit: © Alekss / Fotolia

How could the existing methodology be so flawed? The study’s authors believe that the influence of certain processes was overlooked. For over 50 years, the scientific community based its estimates on what they learned from foraminifera, which are the fossils of tiny marine organisms found in sediment cores taken from the ocean floor. The foraminifera form calcareous shells called tests in which the content of oxygen-18 depends on the temperature of the water in which they live. Changes in the ocean’s temperature over time were therefore calculated on the basis of the oxygen-18 content of the fossil foraminifera tests found in the sediment. According to these measurements, the ocean’s temperature has fallen by 15 degrees over the past 100 million years.

Yet all these estimates are based on the principle that the oxygen-18 content of the foraminifera tests remained constant while the fossils were lodged in the sediment. Indeed, until now, nothing indicated otherwise: no change is visible to the naked eye or under the microscope. To test their hypothesis, the authors of this latest study exposed these tiny organisms to high temperatures in artificial sea water that contained only oxygen-18. Using a NanoSIMS (nanoscale secondary ion mass spectrometer), an instrument used to run very small-scale chemical analyses, they then observed the incorporation of oxygen-18 in the calcareous shells. The results show that the level of oxygen-18 present in the foraminifera tests can in fact change without leaving a visible trace, thereby challenging the reliability of their use as a thermometer: “What appeared to be perfectly preserved fossils are in fact not. This means that the paleotemperature estimates made up to now are incorrect,” says Sylvain Bernard, a CNRS researcher at the Paris-based Institute of Mineralogy, Materials Physics and Cosmochemistry and the study’s lead author.

For the French and Swiss team of researchers, rather than showing a gradual decline in ocean temperatures over the past 100 million years, these measurements simply reflect the change in oxygen-18 content in the fossil foraminifera tests. And this change appears to be the result of a process called re-equilibration: during sedimentation, temperatures rise by 20 to 30°C, causing the foraminifera tests to re-equilibrate with the surrounding water. Over the course of some ten million years, this process has a significant impact on paleotemperature estimates, especially those based on foraminifera that lived in cold water. Computer simulations run by the researchers suggest that paleotemperatures in the ocean depths and at the surface of the polar ocean have been overestimated.

For Meibom, the next steps are clear: “To revisit the ocean’s paleotemperatures now, we need to carefully quantify this re-equilibration, which has been overlooked for too long. For that, we have to work on other types of marine organisms so that we clearly understand what took place in the sediment over geological time.” The article’s authors are already hard at work.

  1. S. Bernard, D. Daval, P. Ackerer, S. Pont, A. Meibom. Burial-induced oxygen-isotope re-equilibration of fossil foraminifera explains ocean paleotemperature paradoxes. Nature Communications, 2017; 8 (1) DOI: 10.1038/s41467-017-01225-9
  2. Ecole Polytechnique Fédérale de Lausanne. “Current climate change unparalleled over the last 100 million years?.” ScienceDaily. ScienceDaily, 26 October 2017. <www.sciencedaily.com/releases/2017/10/171026085756.htm>

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WFS Dino Facts : Ophthalmosaurus ‭(‬Eye lizard‭)

October 30th, 2017 Riffin

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Name: Ophthalmosaurus ‭(‬Eye lizard‭)‬.
Phonetic: Of-fal-moe-sore-us.
Named By: Harry Govier Seeley‭ ‬-‭ ‬1874.
Synonyms: Apatodontosaurus,‭ ‬Ancanamunia,‭ ‬Baptanodon,‭ ‬Paraophthalmosaurus,‭ ‬Yasykovia.
Classification: Chordata,‭ ‬Reptilia,‭ ‬Ichthyosauria,‭ ‬Ophthalmosauridae,‭ ‬Ophthalmosaurinae.
Species: O.‭ ‬icenicus‭ (‬type‭)‬,‭ ‬O.‭ ‬natans,‭ ‬O.‭ ‬saveljeviensis,‭ ‬O.‭ ‬yasykovi.
Diet: Piscivore,‭ ‬possibly a specialist in deep water squid.
Size: Up to‭ ‬6‭ ‬meters long.
Known locations: England – Oxford Clay Formation. France. Greenland, Mexico – La Caja Formation. USA, Wyoming – Sundance Formation.
Time period: Bathonian through to Tithonian of the Jurassic.
Fossil representation: Lots of specimens of individuals of all ages which make Ophthalmosaurus one of the best known ichthyosaurs.

       The large number of remains relating to Ophthalmosaurus has not only indicated that it was a common ichthyosaur of the late Jurassic,‭ ‬but they have formed the basis to a lot of research about ichthyosaurs in general.‭ ‬Perhaps one of the most important areas is that concerning live birth in marine reptiles,‭ ‬something which has been proven in other ichthyosaur genera such as Platypterygius,‭ ‬but in Ophthalmosaurus is proved by the total discovery of over fifty different pregnant females.‭ ‬Further to this it seems that Ophthalmosaurus at least gave birth to multiple young at the time with numbers of pups inside a mother’s body being anything between two and eleven.‭ ‬As such it is very likely that other genera of ichthyosaurs also gave birth to litters of several individual pups.
The sources of the inspiration of the name Ophthalmosaurus are the large eyes.‭ ‬Not only did they take up most of the orbital cavity,‭ ‬but Ophthalmosaurus possibly had the proportionately largest eyes amongst the known sea creatures of the late Jurassic seas.‭ ‬These large eyes were obviously to provide Ophthalmosaurus with vision in low light levels,‭ ‬and while the two main theories are nocturnal activity or deep water hunting,‭ ‬current fossil evidence provides much stronger support for the latter.

Ophthalmosaurus ‭(‬Eye lizard‭)‬

   Ophthalmosaurus ‭(‬Eye lizard‭)‬

       The eyes of Ophthalmosaurus were supported by bony growths called scleral rings,‭ ‬features that in themselves are very common,‭ ‬but the scleral rings associated with Ophthalmosaurus are extremely well developed.‭ ‬Beyond the obvious large size of the eye these rings would have supported the eye against the crushing effect of the water that would have been at a much higher pressure than the water nearer the surface.‭ ‬Additionally examination of the joints of Ophthalmosaurus has revealed damage to the bones caused by decompression sickness‭ (‬better known as‭ ‘‬the bends‭’)‬.‭ ‬This is where the body moves‭ ‬from‭ ‬higher to lower pressure levels faster than the body can adjust which causes gases that are dissolved in the blood stream to be released.‭ ‬This indicates that Ophthalmosaurus would have had to dive very deep in order for it to be able to sustain these kinds of injuries.
The reasons why an ichthyosaur like Ophthalmosaurus would dive into deep water are varied,‭ ‬one of which is predator evasion.‭ ‬The late Jurassic seas saw large pliosaurs like Liopleurodon and Pliosaurus as the dominant predators of other marine reptiles and Ophthalmosaurus may have dived deep in order to avoid them,‭ ‬the bends injuries being caused as a result of this avoiding action.‭ ‬However the large eyes of Ophthalmosaurus suggest that deep diving into low light layers was a matter of routine rather than escape,‭ ‬otherwise it would have had eyes similar to other near surface dwelling ichthyosaurs.‭ ‬The deeper down in the water you go the more water there is for the surface light to pass through which means the ocean can soon become so dark that all you would be able to see is black.‭ ‬These dark layers however are usually abundant in creatures like squid however,‭ ‬and by focusing upon a source of prey like this,‭ ophthalmosaurid ichthyosaurs could co-exist with other types of ichthyosaurs that were dedicated fish hunters.
A possible further adaption to deep water are the disc-shaped vertebrae which are closely packed together,‭ ‬reducing the amount of space available for gases to build up between them.‭ ‬More in depth study by palaeontologists has suggested that Ophthalmosaurus may have been able to dive well beyond five hundred meters deep,‭ ‬and possibly stay down for as much as twenty minutes at a time.‭
Ophthalmosaurus is the type genus of the ophthalmosauridae group which includes other big eyed ichthyosaurs that are similar in form to Ophthalmosaurus.‭ ‬This however has led to some confusion between which genera deserve to be kept separate from Ophthalmosaurus,‭ ‬but still in the same group,‭ ‬and which actually represent other previously described genera.‭ ‬Mollesaurus periallus that was once classed as a synonym ofOphthalmosaurus has since been re-examined and confirmed as representing a distinct genus.‭ ‬Undorosaurus is also once again accepted by the majority of researchers as being valid,‭ ‬although some still list it as a synonym.‭ ‬One species of Ophthalmosaurus,‭ ‬O.‭ ‬chrisorum,‭ ‬has since been‭ ‬redescribed as its own genus,‭ ‬Arthropterygius.‭ ‬Out of all the ophthalmosaurid ichthyosaurs,‭ ‬Acamptonectes and Mollesaurus are thought to be two of the most closely related to Ophthalmosaurus.

Further reading
– On the pectoral arch and fore limb of Ophthalmosaurus, a new ichthyosaurian genus from the Oxford Clay. – Quarterly Journal of the Geological Society of London 30:696-707. – H. G. Seeley – 1874.
– The osteology and taxonomy of the fossil reptile Ophthalmosaurus. – Proceedings of the Zoological Society of London 126(3):403-448. – R. M. Appleby – 1956.
– First discovery of the ichthyosaur Opthalmosaurus in the Kimmeridgian of the USSR. – Paleontological Journal 112-114. – B. M. Efimov – 1991.
– The first definite record of a Valanginian ichthyosaur and its implications on the evolution of post-Liassic Ichthyosauria. – Cretaceous Research 32 (2): 155–163. – V. Fischer, A. Clement, M. Guiomar & P. Godefroit – 2011.
– A new Barremian (Early Cretaceous) ichthyosaur from western Russia. – Journal of Vertebrate Paleontology 31 (5): 1010–1025. – Valentin Fischer, Edwige Masure, Maxim S. Arkhangelsky & Pascal Godefroit – 2011.
– New Ophthalmosaurid Ichthyosaurs from the European Lower Cretaceous Demonstrate Extensive Ichthyosaur Survival across the Jurassic–Cretaceous Boundary. – PLoS ONE 7 (1): e29234. – Valentin Fischer, Michael W. Maisch, Darren Naish, Ralf Kosma, Jeff Liston, Ulrich Joger, Fritz J. Krüger, Judith Pardo Pérez, Jessica Tainsh & Robert M. Appleby – 2012.

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WFS News: Fossil Footprints Reveal Existence of Big Early Dinosaur Predator

October 29th, 2017 Riffin

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WASHINGTON (Reuters) – A trail of fossilized three-toed footprints that measure nearly two feet (57 cm) long shows that a huge meat-eating dinosaur stalked southern Africa 200 million years ago at a time when most carnivorous dinosaurs were modest-sized beasts.

Scientists on Thursday described the footprints from an ancient river bank in Lesotho, and estimated that the dinosaur, which they named Kayentapus ambrokholohali, was about 30 feet (9 meters) long.

No fossilized bones were found, but the footprints alone showed a lot about the animal. The scientists concluded it was a large theropod — the two-legged carnivorous dinosaur group that included later giants like Tyrannosaurus and Giganotosaurus — but that it was more lightly built than those brutes. The theropod group also gave rise to birds.

Fabien Knoll, Honorary Senior Research Fellow at the University of Manchester, lies next to the exceptionally large carnivorous dinosaur footprints found in Lesotho, Africa in this undated handout photo obtained by Reuters October 26, 2017. Fabien Knoll/University of Manchester/Handout via REUTERS Reuters

Fabien Knoll, Honorary Senior Research Fellow at the University of Manchester, lies next to the exceptionally large carnivorous dinosaur footprints found in Lesotho, Africa in this undated handout photo obtained by Reuters October 26, 2017. Fabien Knoll/University of Manchester/Handout via REUTERS Reuters

Kayentapus lived early in the Jurassic Period, shortly after a mass extinction that doomed other large reptilian terrestrial predators that lived in the preceding Triassic Period, when dinosaurs first appeared.

 “Our finding corroborates the hypothesis that theropods reached a great size relatively early in the course of their evolution, but apparently not before the Triassic-Jurassic boundary,” said paleontologist Fabien Knoll, of the Dinopolis Foundation in Spain and the University of Manchester in Britain.

There are no skeletal fossils of meat-eating dinosaurs this large so early in the dinosaur evolutionary history. It lived on the ancient southern hemisphere super-continent of Gondwana.

There are other fossilized footprints from Poland that indicate a similar-sized theropod inhabited the northern super-continent of Laurasia around the same time.

Theropods of similar size do not appear in the fossil record until 30 million years later, Knoll said.

 The footprints were found on what was once a river bank, bearing telltale ripple marks and desiccation cracks.

“It is the first evidence of an extremely large meat-eating animal roaming a landscape otherwise dominated by a variety of herbivorous, omnivorous and much-smaller carnivorous dinosaurs,” added paleontologist Lara Sciscio of the University of Cape Town in South Africa.

The research was published on Wednesday in the journal PLOS ONE.

In separate research, other scientists on Thursday described another new dinosaur, a plant-eater called Matheronodon provincialis, that lived 70 million years ago. Its fossils were unearthed in southern France.

Matheronodon is distinctive for its large teeth with a chisel-like cutting edge that provided a powerful shearing action like scissors to eat tough vegetation, said paleontologist Pascal Godefroit of the Royal Belgian Institute of Natural Sciences in Brussels.

That research was published in the journal Scientific Reports.

Source: News By Will Dunham (Reporting by Will Dunham; Editing by Sandra Maler).C.R.Thomson Reuters.

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WFS News: Ichthyosaur fossil discovered for first time in India

October 26th, 2017 Riffin

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Scientists in India have discovered a 152 million-year-old fossil of an ichthyosaur – an extinct marine reptile – in the western state of Gujarat.

This is the first time an ichthyosaur fossil has been discovered in India.The fossil was found inside rocks from the Mesozoic Era, which ran between 252 and 66 million years ago, in the Kutch desert.

Prof Guntupalli VR Prasad, who led the study, said the 5.5m (18ft) specimen was almost complete.

Only parts of the skull and tail bones were found to be missing.The findings have been published in the Plos One science journal.

This is the first time an ichthyosaur fossil has been discovered in India

 This is the first time an ichthyosaur fossil has been discovered in India

“This is a remarkable discovery not only because it is the first Jurassic ichthyosaur record from India, but also it throws light on the evolution and diversity of ichthyosaurs in the Indo-Madagascan region and India’s biological connectivity with other continents in the Jurassic,” Mr Prasad said.

The team, which comprised scientists from India and Germany, believes the newly discovered specimen can be identified with Ophthalmosauridae, a family of ichthyosaurs that lived in the oceans between 165 and 90 million years ago.

  • Often misidentified as “swimming dinosaurs”, they first appeared in the early Triassic period (251 million to 199 million years ago)
  • The name means fish-lizard, although the creature has been classified as a reptile since the mid-19th Century
  • Its length ranged from 1m to 14m – although the average length was 2m to 3m
  • The creature was noted for its sharp, robust teeth.
  • Ichthyosaurs became extinct around 90 million years ago.

Source: Encyclopaedia of Paleontology.

A statement from the team said the identification of the new specimen may further throw light on whether there was any marine connection between India and South America about 150 million years ago.

An examination of the teeth of the fossil suggests that it was a top-tier predator in its ecosystem, it added.

Source:BBC News

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WFS News:Growing pains: The oldest trees on Earth ripped themselves apart, fossils show

October 25th, 2017 Riffin

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Scientists have discovered 374-million-year-old tree fossils from the dawn of Earth’s forests — and found that these strange plants literally had to rip themselves apart as they grew.

The fossils, described in the Proceedings of the National Academy of Sciences, shed light on the nature of ancient forests and the evolution of the Earth’s climate.

The Xinicaulis lignescens fossils, discovered in Xinjiang, China, are part of a group of species known as Cladoxylopsida — plants that have no known descendants but are thought to be related to the ancestors of today’s ferns and horsetails. They could grow about 10 to 12 meters tall and one meter wide at the base; their branches popped out of the top of the trunk, giving it a shape similar to today’s palms. These branches sprouted further, tinier appendages that were not yet true leaves.

A late Devonian Xinicaulis tree trunk fossil from northwest China. (PNAS.)

                                                   A late Devonian Xinicaulis tree trunk fossil from northwest China. (PNAS.)

Cladoxylopsida emerged in some of Earth’s earliest forests, during the Mid- to early Late Devonian period, around 393 million to 372 million years ago. There were bugs, and millipedes that may have munched on dead plant matter, but by and large these trees faced no major predators — vertebrate animals only just started getting a toehold on land in the late Devonian. These trees filled ancient forests by the millions.

“It’s just a fundamental change in the whole way that the Earth’s system works once you put large plants in forests onto a planet,” said study coauthor Christopher Berry, a paleobotanist at Cardiff University.

Understanding these long-gone trees could help scientists understand the evolution of Earth’s climate and biology during this pivotal time. But until now, the recovered fossils have usually been fallen, squashed trees, or natural sandstone casts of decomposing stumps. Neither gives much structural information.

“They tell you about shapes, they don’t tell you very much about growth and the anatomy,” Berry said.

If you cut open a typical tree today, you’ll find that the xylem (the woody tissue that carries water up through the tree) grows outward from the center, forming concentric rings. But in the ancient specimens, the xylem grew in individual strands that clustered only in the outer five centimeters or so of the trunks, and were joined together by a complicated network of tinier strands. The center of the tree was hollow; all this activity took place in the thick woody ring around that empty space.

The structure was somewhat akin to the Eiffel Tower, Berry said: big, strong strands running down the outside corners, connected by a network of shorter bars — all surrounding a hollow middle.

“We couldn’t imagine how these things could possibly grow,” Berry said.

The two new fossil finds, an 8-centimeter specimen and a much larger 70-centimeter-wide trunk, shed some light on that mystery. Thanks to volcanic sediments, tiny grains of silica were able to penetrate deep into the trees’ tissues, preserving their structure on a cellular level — and allowing scientists to study it in unprecedented detail.

The researchers found that those individual xylem strands were actually growing like miniature trees, developing tiny ring after ring. What’s more, as the tree grew, the xylem fibers would actually tear themselves apart.

“In order to expand this trunk, all those interconnections have to slowly rip apart in order to accommodate the growth of the plant — and that was what we saw in the specimen,” Berry said. “As they were being pulled apart to make the tree bigger, they were also repairing themselves at the same time.”

As it grew, the strange tree’s trunk would bulge and ultimately collapse outward — forming a wider base in the process.

“This thing seems to be behaving in an organized way even though it’s so outrageous,” Berry said.

It’s unclear why these trees died out; it’s possible they were out-competed by new forms of trees that actually had leaves, and were ‘shaded out’ of the forest canopy. Perhaps a frosty period near the end of the Devonian killed them off. It’s also possible that the plants, which pulled down so much carbon dioxide from the air, might have taken out too much and starved themselves.

The next step, Berry said, is to probe how much carbon dioxide these plants really could have taken out of the air. That’s important because carbon dioxide isn’t just fuel for plants — it’s a greenhouse gas that traps heat.

“If we can work out how much carbon it absorbed over a certain amount of time,” Berry said, “then we’ll learn a little bit more about how capable it was of actually changing the atmosphere of the planet.”

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Source:Article by Amina Khan :http://www.latimes.com

WFS News:Fossils from the world’s oldest trees reveal complex anatomy never seen before

October 25th, 2017 Riffin

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The first trees to have ever grown on Earth were also the most complex, new research has revealed.

The strands, known as xylem, are responsible for conducting water from a tree’s roots to its branches and leaves. In the most familiar trees the xylem forms a single cylinder to which new growth is added in rings year by year just under the bark. In other trees, notably palms, xylem is formed in strands embedded in softer tissues throughout the trunk.

Writing in the journal Proceedings of the National Academy of Sciences, the scientists have shown that the earliest trees, belonging to a group known as the cladoxlopsids, had their xylem dispersed in strands in the outer 5 cm of the tree trunk only, whilst the middle of the trunk was completely hollow.

Illustrative transverse plane through the small trunk, showing the three naturally-fractured parts. Credit: Xu and Berry, 2017. Read more at: https://phys.org/news/2017-10-fossils-world-oldest-trees-reveal.html#jCp

Illustrative transverse plane through the small trunk, showing the three naturally-fractured parts. Credit: Xu and Berry, 2017.

The narrow strands were arranged in an organised fashion and were interconnected to each other like a finely tuned network of water pipes.

The team, which includes researchers from Cardiff University, Nanjing Institute of Geology and Palaeontology, and State University of New York, also show that the development of these strands allowed the tree’s overall growth.

Rather than the tree laying down one growth ring under the bark every year, each of the hundreds of individual strands were growing their own rings, like a large collection of mini trees.

As the strands got bigger, and the volume of soft tissues between the strands increased, the diameter of the tree trunk expanded. The new discovery shows conclusively that the connections between each of the strands would split apart in a curiously controlled and self-repairing way to accommodate the growth.

At the very bottom of the tree there was also a peculiar mechanism at play – as the tree’s diameter expanded the woody strands rolled out from the side of the trunk at the base of the tree, forming the characteristic flat base and bulbous shape synonymous with the cladoxylopsids.

Co-author of the study Dr Chris Berry, from Cardiff University’s School of Earth and Ocean Sciences, said: “There is no other tree that I know of in the history of the Earth that has ever done anything as complicated as this. The tree simultaneously ripped its skeleton apart and collapsed under its own weight while staying alive and growing upwards and outwards to become the dominant plant of its day.

“By studying these extremely rare fossils, we’ve gained an unprecedented insight into the anatomy of our earliest trees and the complex growth mechanisms that they employed.

“This raises a provoking question: why are the very oldest trees the most complicated?”

Dr Berry has been studying cladoxylopsids for nearly 30 years, uncovering fragmentary fossils from all over the world. He’s previously helped uncovered a previously mythical fossil forest in Gilboa, New York, where cladoxylopsid trees grew over 385 million years ago.

Yet Dr Berry was amazed when a colleague uncovered a massive, well-preserved fossil of a cladoxylopsid tree trunk in Xinjiang, north-west China.

“Previous examples of these trees have filled with sand when fossilised, offering only tantalising clues about their anatomy. The fossilised obtained from Xinjiang was huge and perfectly preserved in glassy silica as a result of volcanic sediments, allowing us to observe every single cell of the plant,” Dr Berry continued.

The overall aim of Dr Berry’s research is to understand how much carbon these were capable of capturing from the atmosphere and how this effected the Earth’s climate.

Explore further: Tropical trees maintain high carbon accumulation rates into old age

More information: Hong-He Xu el al., “Unique growth strategy in the Earth’s first trees revealed in silicified fossil trunks from China,” PNAS (2017). www.pnas.org/cgi/doi/10.1073/pnas.1708241114

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Read more at: https://phys.org/news/2017-10-fossils-world-oldest-trees-reveal.html#jCp

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