WFS Dino Facts: Nyctosaurus

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Name: Nyctosaurus ‭(‬Night lizard‭)‬.
Phonetic: Nick-toe-sore-us.
Named By: Othniel Charles Marsh‭ ‬-‭ ‬1876.
Synonyms: Nyctodactylus.
Classification: Chordata,‭ ‬Reptilia,‭ ‬Pterosauria,‭ ‬Pterodactyloidea,‭ ‬Nyctosauridae,‭ ‬Nyctosaurinae.
Species: N.‭ ‬gracilis‭ (‬type‭)‬,‭ ‬N.‭ ‬nanus,‭ ‬N.‭ ‬lamegoi,‭ ‬N.‭ ‬bonneri.
Type: Piscivore.
Size: 2‭ ‬meter wingspan,‭ ‬possibly larger.
Known locations: USA,‭ ‬Kansas‭ ‬-‭ ‬Niobrara Formation.
Time period: Campanian of the Cretaceous.
Fossil representation: Many individuals.

       Although many pterosaurs sported elaborate head crests,‭ ‬Nyctosaurus took things to a new extreme.‭ ‬Rising up to over half a meter high,‭ ‬a proportionately massive‭ ‘‬L‭’ ‬shaped crest is known to have been present on Nyctosaurus.‭ ‬This crest was once thought to have been the support for a skin sail,‭ ‬but today it is generally accepted that the crest was more or less as it was preserved,‭ ‬with it sometimes being referred to as a pterosaur‭ ‘‬deer antler‭’ ‬from its appearance.‭ ‬Although it may appear cumbersome,‭ ‬the crest was actually very light,‭ ‬and studies have shown it would have had very little impact upon the flying ability of Nyctosaurus.‭ ‬It is however somewhat harder to say if it actually imparted any positive benefits.

Nyctosaurus dimensions

Nyctosaurus dimensions

Study of sub‭ ‬adult specimens has raised the notion that Nyctosaurus reached full size within its first year,‭ ‬and that the crest started growing when the individual in question reached adulthood.‭ ‬The crest may have been growing throughout the entire adult life of Nyctosaurus,‭ ‬with the largest crests belonging to the oldest,‭ ‬and henceforth most successful individuals.‭ ‬This would serve to persuade potential mates that the larger crest was superior to the smaller.
Another special feature of Nyctosaurus is the complete absence of claws from the first,‭ ‬second and third digits of the hand.‭ ‬This means that Nyctosaurus would have had a hard time clinging onto things while on the ground and has brought the suggestion that Nyctosaurus may have spent most of its time flying in the air.‭ ‬A potential benefit of the lack of claws however is that the wings would have been even more streamlined.‭ ‬Because the fossils of Nyctosaurus are known from the Niobrara Formation,‭ ‬it’s a safe assumption that it would have flown over the Western Interior Seaway while looking for fish.

nyctosaurus skeleton

   nyctosaurus fossil

With the exception of the head crest being completely different,‭ ‬Nyctosaurus often draws comparisons with the well-known pterosaur,‭ ‬Pteranodon.‭ ‬Not only do they have similar body morphology,‭ ‬both Nyctosaurus and Pteranodon have been found in the same fossil formation,‭ ‬and both would have shared the skies of the late Cretaceous at the same time as one another.‭ ‬However Nyctosaurus has a much shorter presence in the fossil record of approximately only half a million years,‭ ‬whereas Pteranodon spanned over seven million years.

nyctosaurus skeleton

         nyctosaurus 

Because of its similar body morphology to Pteranodon,‭ ‬Nyctosaurus may have flown in a similar manner,‭ ‬including using a process known as dynamic soaring.‭ ‬Dynamic soaring is where a flying creature such as an Albatross flies into the trough formed by two waves and into the lee of a passing wave.‭ ‬The lee is the change that results in stronger air pressure that occurs as the wave moves along,‭ ‬and this pressure results in air moving faster over the wings and increasing their lift.‭ ‬The animal in question can then turn around sharply,‭ ‬a process called‭ ‘‬wheeling‭’‬,‭ ‬and then head back towards the trough with a back wind that further increases speed.
The number of species attributed to Nyctosaurus has changed since its discovery,‭ ‬and even some of the species listed above may yet prove to be identical to the type species.‭ ‬Only time with further study and hopefully new fossils will be able to establish the exact species with certainty.

Further reading
– Notice of a new sub-order of Pterosauria. – American Journal of Science, 11(3): 507-509. – O. C. Marsh – 1876a.
– Principal characters of American pterodactyls. – American Journal of Science, 12: 479-480. – O. C. Marsh – 1876b.
– Note on American pterodactyls. – American Journal of Science, 21: 342-343. – O. C. Marsh – 1881.
– New crested specimens of the Late Cretaceous pterosaur Nyctosaurus. – Paläontologische Zeitschrift, 77: 61-75. – S. C. Bennett – 2003.
– Posture, Locomotion, and Paleoecology of Pterosaurs. – Geological Society of America – S. Chatterjee & R. J. Templin – 2004.
– Aerodynamic characteristics of the crest with membrane attachment on Cretaceous pterodactyloid Nyctosaurus. – Acta Geologica Sinica, 83(1): 25-32. – L. Xing, J. Wu, Y. Lu & Q. Ji – 2009.

Source: Prehistoric wildlife.com

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WFS News: Hyolith fossils find place on the tree of life

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A strange animal that lived on the ocean floor 500 million years ago has been assigned to the tree of life, solving a long-held mystery.

The creature has eluded scientific classification since the first fossil was discovered 175 years ago.The extinct hyolith has a cone-shaped shell, tentacles for feeding and appendages that acted as “feet”.It belongs to an invertebrate group that includes animals such as the horseshoe worm, say scientists.

Joseph Moysiuk, of the University of Toronto, made the discovery after analysing more than 1,500 specimens dug out of rocks in Canada and the US.

The feeding tentacles were used to filter water for food

  Hyoliths, The feeding tentacles were used to filter water for food

“Hyoliths are small cone-shaped sea dwelling animals. They are known from all around the world, mostly from fossils of their shells,” he told BBC News.

“They appear in the fossil record about 530 million years ago and survived until about 250 million years ago.

“But the question of where hyoliths actually fit into the tree of life has been somewhat of a mystery for the last 175 years, since they were first described.”

The research, published in the journal Nature, analysed soft tissue preserved in “very special fossils” from a site in Canada known as the Burgess Shale.In the past, hyoliths have been interpreted as being related to molluscs, which are common today and include squid, clams and snails.The new research suggests the animals are in fact more closely related to a different group of shell-bearing organisms, known as lophophorata, which includes brachipods (lamp shells), among others.

Ancient seas

Hyoliths were present from the beginning of the Cambrian period about 540 million years ago, during a rapid burst of evolution that gave rise to most of the major animal groups.

The new fossils were found in Canada

     The new fossils were found in Canada

“Being able to place them on the tree of life, it solves this long paleontological mystery about what these creatures are,” said Joseph Moysiuk.

“We have been able to discover some new features of a very old group of fossil animals, and it’s allowed us to reveal the evolutionary history of this group of animals and where exactly they sit on the tree of life.”

Dr Martin Smith, of the University of Durham, UK, also worked on the fossils.He said by placing hyoliths in their rightful home and understanding how they lived, scientists now had a better picture of life in the ancient seas.This gives an insight into the impact of mass extinction events such as the Permian-Triassic mass extinction, which wiped out most animal life, including the hyoliths.

“Understanding the effects of such mass extinctions on ecology and diversity is particularly important as we seek to appraise and mitigate the implications of the current mass extinction event brought about by human activity,” Dr Smith said.

Source: Article By 

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WFS News: Fossil tomatillos show nightshades

Delicate fossil remains of tomatillos found in Patagonia, Argentina, show that this branch of the economically important family that also includes potatoes, peppers, tobacco, petunias and tomatoes existed 52 million years ago, long before the dates previously ascribed to these species, according to an international team of scientists.

Tomatillos, ground cherries and husk tomatoes — members of the physalis genus — are unusual because they have papery, lantern-like husks, known to botanists as inflated calyces that grow after fertilization to extend around their fleshy, often edible berries. They are a small portion of the nightshade family, which includes many commercially, scientifically and culturally valuable plants among its more than 2,400 living species. This entire family has had a notably poor fossil record, limited to tiny seeds and wood with little diagnostic value that drastically limited understanding of when and where it evolved.

The researchers examined two fossil lantern fruit collected at Laguna del Hunco, Chubut, Patagonia, Argentina, in an area that was temperate rainforest when the plants grew, 52 million years ago. These are the only physalis fossils found among more than 6,000 fossils collected from this remote area, and they preserve very delicate features such as the papery husk and the berry itself. The fossil site, which has been the focus of a Penn State, Museo Palentologico Egidio Feruglio, Trelew, Argentina, and Cornell University project for more than a decade, was part of terminal Gondwana, comprised of the adjacent landmasses of South America, Antarctica and Australia during a warm period of Earth history, just before their final separation.

“These astonishing, extremely rare specimens of physalis fruits are the only two fossils known of the entire nightshade family that preserve enough information to be assigned to a genus within the family,” said Peter Wilf, professor of geosciences, Penn State. “We exhaustively analyzed every detail of these fossils in comparison with all potential living relatives and there is no question that they represent the world’s first physalis fossils and the first fossil fruits of the nightshade family. Physalis sits near the tips of the nightshade family’s evolutionary tree, meaning that the nightshades as a whole, contrary to what was thought, are far older than 52 million years.”

Typically, researchers look for fossilized fruits or flowers as their first choice in identifying ancient plants. Because the fruits of the nightshade family are very delicate and largely come from herbaceous plants with low biomass, they have little potential to fossilize. The leaves and flowers are also unknown from the fossil record. This presents a problem for understanding when and where the group evolved and limits the use of fossils to calibrate molecular divergence dating of these plants.

The new fossil groundcherry Physalis infinemundi from Laguna del Hunco in Patagonia, Argentina, 52 million years old. This specimen displays the characteristic papery, lobed husk and details of the venation. Credit: Ignacio Escapa, Museo Paleontológico Egidio Feruglio

The new fossil groundcherry Physalis infinemundi from Laguna del Hunco in Patagonia, Argentina, 52 million years old. This specimen displays the characteristic papery, lobed husk and details of the venation.
Credit: Ignacio Escapa, Museo Paleontológico Egidio Feruglio

Molecular dating of family trees relies on actual dates of fossils in the family to work from. Because the previous dated fossils had little diagnostic value beyond their membership in the large nightshade family, molecular dating was difficult.

The researchers note in Science that “The fossils are significantly older than corresponding molecular divergence dates and demonstrate an ancient history for the inflated calyx syndrome.”

Molecular dates calibrated with previous fossils had placed the entire nightshade family at 35 to 51 million year ago and the tomatillo group, to which the 52 million year old fossils belong, at only 9 to 11 million years ago.

Using direct geologic dating of materials found with the fossils — argon-argon dating of volcanic tuffs and recognition of two magnetic reversals of the Earth’s poles — the team had previously dated the rocks containing the fossil fruit to 52 million years ago.

“Paleobotanical discoveries in Patagonia are probably destined to revolutionize some traditional views on the origin and evolution of the plant kingdom,” said N. Rubén Cúneo, CONICET, Museo Palentológico Egidio Feruglio. “In this regard, the Penn State/ MEF/Cornell scientific partnership is showing the strength of international collaborations to bring light and new challenges to the exciting world of discovering the secrets of Earth life.”

Mónica Carvalho, former Penn State M.S. student now a Ph.D. student at the School of Integrative Plant Science, Cornell, and Wilf did the evolutionary analysis of the morphology of current members of the family and the fossils, combined with genetic analysis of the living species.

“These fossils are one of a kind, since the delicate papery covers of lantern fruits are rarely preserved as fossils,” Carvalho said. “Our fossils show that the evolutionary history of this plant family is much older than previously considered, particularly in South America, and they unveil important implications for understanding the diversification of the family.”

All members of the physalis genus are New World species inhabiting South, Central and North America. Their center of diversity is Mexico.

The researchers note that the physalis fossils show a rare link from late-Gondwanan Patagonian to living New World plants, but most other fossil plants, such as eucalyptus, found at the site have living relatives concentrated in Australasia. That pattern reflects the ancient overland connection across terminal Gondwana from South America to Australia through Antarctica. The new research raises the possibility that more, potentially much older, nightshade fossils may be found at far southern locations.

“Our results reinforce the emerging pattern wherein numerous fossil plant taxa from Gondwanan Patagonia and Antarctica are substantially older than their corresponding molecular dates, demonstrating Gondwanan history to groups conjectured to have post-Gondwanan origins under entirely different paleogeographic and paleoclimatic scenarios,” the researchers wrote.

Citation: Penn State. “South American fossil tomatillos show nightshades evolved earlier than thought.” ScienceDaily. ScienceDaily, 5 January 2017. <www.sciencedaily.com/releases/2017/01/170105143521.htm>.

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WFS DinoFacts: Avimimus portentosus

Name Means: “Bird mimic” Length: 5 feet (1.5 m)
Pronounced: AYV-ee-MIME-us Weight: 45 pounds (20 kilos)
When it lived: Late Cretaceous – 95 MYA
Where found: Mongolia, China

Avimimus was discovered by Russian paleontologist Sergei Mikhailovich Kurzanov during the exploration of the Joint Soviet-Mongolian paleontological expedition in the summer of 1973, at the Udan-Sayr (southern Gobi) location in Mongolia. It was a  fairly complete skeleton of a bird-like theropod. With the exception of a crushed skull fragment, the bones were very well preserved.   Udan-Sayr is in the foothills of the Gurvan-Sayhan mountain range.  The red colored sand he deposits are 15 meters thick and can be very accurately dated. This is proven by the presence of teeth from Tarbosaurus, a carnosaur, known from the deposits of that age from various locations in the Southern Gobi. Three other partial skeletons were later recovered.  It was named by Kurzanov in 1981.

Avimimus looked so much like a bird that its name literally means that it imitates a bird.  It looks like a large reptilian roadrunner. Avimimus had a long, lean neck topped by a short skull that was equipped with a toothless beak and a relatively large braincase. It had long, slender back legs built for fast running. But its front limbs had not yet evolved into wings.  They were lightly built and equipped with sharp, curved claws. The bones in it’s wrists were actually fused together, much like that of the modern day cockatoo. In fact, Avimimus had the ability to fold its whole arm against its body, much like the wings of a bird. Unlike a bird however, Avimimus had a long bony tail. What’s more, its pelvis resembled that of other theropods.
It was the first dinosaur to so clearly express bird features, in such large numbers.  It is also the first theropods with such unusual structure of the pelvis. Such a combination of unique features places Avimimus in a category all its own.

Avimimus portentosus

Avimimus portentosus

   It is possible that Avimimus had feathers, however, deposits around its body are too coarse for such features to be preserved. However it was unearthed near other dinosaurs similar to itself, particularly Sinosauropteryx and Caudipteryx and their feathers were preserved. Even though none have so far been found, there is evidence that Avimimus could have had feathers.  There are small ridges on its forearm that could be anchor points for feather shafts.  Modern birds have bone “dimples” at the point of feather attachment, however the ridges present in Avimimus could be a pre-adaptation to feather attachment. Even if Avimimus did have feathers, it would seem very unlikely that it would be able to achieve flight, particularly due to its large body.
     One of the great enigmas to have surfaced in the last quarter century of dinosaur paleo, Avimimus has features that could be ascribed to sauropods, hadrosaurids, basal theropods, oviraptorids, birds, and ornithomimids.  Sometimes considered a chimera, recent remains indicate it was an Oviraptor.

Courtesy:http://www.dinosaur-world.com

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WFS news: Limusaurus, A dinosaur species lost its teeth in adolescence

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Researchers have discovered that a species of dinosaur, Limusaurus inextricabilis, lost its teeth in adolescence and did not grow another set as adults. The finding, published today in Current Biology, is a radical change in anatomy during a lifespan and may help to explain why birds have beaks but no teeth.

The research team studied 19 Limusaurus skeletons, discovered in “death traps,” where they became mired in mud, got stuck and died, in the Xinjiang Province of China. The dinosaurs ranged in age from baby to adult, showing the pattern of tooth loss over time. The baby skeleton had small, sharp teeth, and the adult skeletons were consistently toothless.

As Limusaurus grew from adolescent to adult, it lost its teeth and did not grow a new set. Credit: George Washington University

As Limusaurus grew from adolescent to adult, it lost its teeth and did not grow a new set.
                                        Credit: George Washington University

“This discovery is important for two reasons,” said James Clark, a co-author on the paper and the Ronald Weintraub Professor of Biology at the George Washington University’s Columbian College of Arts and Sciences. “First, it’s very rare to find a growth series from baby to adult dinosaurs. Second, this unusually dramatic change in anatomy suggests there was a big shift in Limusaurus‘ diet from adolescence to adulthood.”

Limusaurus is part of the theropod group of dinosaurs, the evolutionary ancestors of birds. Dr. Clark’s team’s earlier research of Limusaurus described the species’ hand development and notes that the dinosaur’s reduced first finger may have been transitional and that later theropods lost the first and fifth fingers. Similarly, bird hands consist of the equivalent of a human’s second, third and fourth fingers.

These fossils indicate that baby Limusaurus could have been carnivores or omnivores while the adults were herbivores, as they would have needed teeth to chew meat but not plants. Chemical makeup in the fossils’ bones supports the theory of a change in diet between babies and adults. The fossils also could help to show how theropods such as birds lost their teeth, initially through changes during their development from babies to adults.

“For most dinosaur species we have few specimens and a very incomplete understanding of their developmental biology,” said Josef Stiegler, a graduate student at George Washington University and co-author. “The large sample size of Limusaurusallowed us to use several lines of evidence including the morphology, microstructure and stable isotopic composition of the fossil bones to understand developmental and dietary changes in this animal.”

Citation: George Washington University. “No teeth? No problem: Dinosaur species had teeth as babies, lost them as they grew: Discovery may explain why birds are toothless.” ScienceDaily. ScienceDaily, 22 December 2016.

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WFS News: Satellites help discover a jet stream in the Earth’s core

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A jet stream within the Earth’s molten iron core has been discovered by scientists using the latest satellite data that helps create an ‘x-ray’ view of the planet.

Lead researcher Dr Phil Livermore, from the University of Leeds, said: “The European Space Agency’s Swarm satellites are providing our sharpest x-ray image yet of the core. We’ve not only seen this jet stream clearly for the first time, but we understand why it’s there.”

“We can explain it as an accelerating band of molten iron circling the North Pole, like the jet stream in the atmosphere,” said Dr Livermore, from the School of Earth and Environment at Leeds.

Swarm's three satellites provide a high-resolution picture of the Earth's magnetic field. Credit: European Space Agency

Swarm’s three satellites provide a high-resolution picture of the Earth’s magnetic field.
                                                                            Credit: European Space Agency

Because of the core’s remote location under 3,000 kilometres of rock, for many years scientists have studied the Earth’s core by measuring the planet’s magnetic field — one of the few options available.

Previous research had found that changes in the magnetic field indicated that iron in the outer core was moving faster in the northern hemisphere, mostly under Alaska and Siberia.

But new data from the Swarm satellites has revealed these changes are actually caused by a jet stream moving at more than 40 kilometres per year.

This is three times faster than typical outer core speeds and hundreds of thousands of times faster than the speed at which the Earth’s tectonic plates move.

The European Space Agency’s Swarm mission features a trio of satellites which simultaneously measure and untangle the different magnetic signals which stem from Earth’s core, mantle, crust, oceans, ionosphere and magnetosphere. They have provided the clearest information yet about the magnetic field created in the core.

The study, published today in Nature Geoscience, found the position of the jet stream aligns with a boundary between two different regions in the core. The jet is likely to be caused by liquid in the core moving towards this boundary from both sides, which is squeezed out sideways.

Co-author Professor Rainer Hollerbach, from the School of Mathematics at Leeds, said: “Of course, you need a force to move the liquid towards the boundary. This could be provided by buoyancy, or perhaps more likely from changes in the magnetic field within the core.”

Rune Floberghagen, ESA’s Swarm mission manager, said: “Further surprises are likely. The magnetic field is forever changing, and this could even make the jet stream switch direction.

“This feature is one of the first deep-Earth discoveries made possible by Swarm. With the unprecedented resolution now possible, it’s a very exciting time — we simply don’t know what we’ll discover next about our planet.”

Co-author Dr Chris Finlay, from the Technical University of Denmark said: “We know more about the Sun than the Earth’s core. The discovery of this jet is an exciting step in learning more about our planet’s inner workings.”

Citation: University of Leeds. “Satellites help discover a jet stream in the Earth’s core.” ScienceDaily. ScienceDaily, 19 December 2016. <www.sciencedaily.com/releases/2016/12/161219134450.htm>.

  1. Philip W. Livermore, Rainer Hollerbach, Christopher C. Finlay. An accelerating high-latitude jet in Earth’s core. Nature Geoscience, 2016; DOI: 10.1038/ngeo2859

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WFS News: Tingmiatornis arctica,a new species of prehistoric bird

A team of geologists at the University of Rochester has discovered a new species of bird in the Canadian Arctic. At approximately 90 million years old, the bird fossils are among the oldest avian records found in the northernmost latitude, and offer further evidence of an intense warming event during the late Cretaceous period.

“The bird would have been a cross between a large seagull and a diving bird like a cormorant, but likely had teeth,” says John Tarduno, professor and chair of the Department of Earth and Environmental Sciences at the University and leader of the expedition.

This is an artist's rendering of Tingmiatornis arctica, the new prehistoric bird species discovered by scientists at the University of Rochester. Credit: Artist rendering by Michael Osadciw/University of Rochester

This is an artist’s rendering of Tingmiatornis arctica, the new prehistoric bird species discovered by scientists at the University of Rochester.Credit: Artist rendering by Michael Osadciw/University of Rochester

Tarduno and his team, which included both undergraduate and graduate students, named the bird Tingmiatornis arctica; “Tingmiat” means “those that fly” in the Inuktitut language spoken in the central and eastern Canadian Arctic (Nunavut territory).

Their findings, published in Scientific Reports, add to previous fossil records Tarduno uncovered from the same geological time period and location in previous expeditions. Taken together, these fossils paint a clearer picture of an ecosystem that would have existed in the Canadian Arctic during the Cretaceous period’s Turonian age, which lasted from approximately 93.9 to 89.8 million years ago.

“These fossils allow us to flesh out the community and add to our understanding of the community’s composition and how it differed from other places in the world,” says Donald Brinkman, vertebrate paleontologist and director of preservation and research at the Royal Tyrrell Museum in Alberta, Canada.

Building historic climate records further helps scientists determine the effects of climate on various communities, ecosystems, and the distribution of species and could help predict the effects of future climatic events.

“Before our fossil, people were suggesting that it was warm, but you still would have had seasonal ice,” Tarduno says. “We’re suggesting that’s not even the case, and that it’s one of these hyper-warm intervals because the bird’s food sources and the whole part of the ecosystem could not have survived in ice.”

Photograph (left) and x-ray computed tomography images (right) of the element in caudal, proximal, cranial, and ventral views.

Photograph (left) and x-ray computed tomography images (right) of the element in caudal, proximal, cranial, and ventral views.

From the fossil and sediment records, Tarduno and his team were able to conjecture that the bird’s environment in the Canadian Arctic during the Turonian age would have been characterized by volcanic activity, a calm freshwater bay, temperatures comparable to those in northern Florida today, and creatures such as turtles, large freshwater fish, and champsosaurs — now-extinct, crocodile-like reptiles.

“The fossils tell us what that world could look like, a world without ice at the arctic,” says Richard Bono, a PhD candidate in earth and environmental sciences at the University and a member of Tarduno’s expedition. “It would have looked very different than today where you have tundra and fewer animals.”

The Tingmiatornis arctica fossils were found above basalt lava fields, created from a series of volcanic eruptions. Scientists believe volcanoes pumped carbon dioxide into Earth’s atmosphere, causing a greenhouse effect and a period of extraordinary polar heat. This created an ecosystem allowing large birds, including Tingmiatornis arctica, to thrive.

Tarduno’s team unearthed three bird bones: part of the ulna and portions of the humerus, which, in birds, are located in the wings. From the bone features, as well as its thickness and proportions, the team’s paleontologist, Julia Clarke of the University of Texas, was able to determine the evolutionary relationships of the new birds as well as characteristics that indicate whether it likely was able to fly or dive.

Photograph of the element in (left to right) cranial, dorsal, ventral, and caudal views.

Photograph of the element in (left to right) cranial, dorsal, ventral, and caudal views.

“These birds are comparatively close cousins of all living birds and they comprise some of the oldest records of fossil birds from North America,” Clarke says. “Details of the upper arm bones tell us about how features of the flightstroke seen in living species came to be.”

Previous fossil discoveries indicate the presence of carnivorous fish such as the 0.3-0.6 meter-long bowfin. Birds feeding on these fish would need to be larger-sized and have teeth, offering additional clues to Tingmiatornis arctica‘s characteristics.

Physiological factors, such as a rapid growth and maturation rate, might explain how this line of bird was able to survive the Cretaceous-Paleogene mass extinction event that occurred approximately 66 million years ago and eliminated approximately three-quarters of the plant and animal species on Earth.

These physiological characteristics are still conjecture, Tarduno emphasizes, but he says the bird’s environment gives clear indications as to why the bird fossils were found in this location.

“It’s there because everything is right,” Tarduno says. “The food supply was there, there was a freshwater environment, and the climate became so warm that all of the background ecological factors were established to make it a great place.”

Courtesy: University of Rochester. “New prehistoric bird species discovered.” ScienceDaily. ScienceDaily, 19 December 2016. <www.sciencedaily.com/releases/2016/12/161219134357.htm>

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WFS News: Gualicho shinyae , Another Dinosaur with Short Arms

No one is sure what, exactly, Tyrannosaurus rex did with its short arms. But Argentinian and American scientists have discovered a new dinosaur species that had the same puzzling feature, they reported this week (July 13) in PLOS One.

Gualicho shinyae, whose 90 million-year-old fossil remains were found in Patagonia, Argentina, was 25 feet long and weighed about a ton—roughly the same size as a polar bear. Yet, full grown, this predator had arms the size of a child’s, New Scientist reported.

G. shinyae and T. rex stem from different evolutionary branches. T. rex’s earliest ancestors had arms that were actually long, study coauthor Peter Makovicky, a paleontologist at the Field Museum of Natural History in Chicago, told The New York Times.But for some reason, T. rex evolved to have stubby arms. Because this trait appears to have arisen independently in G. shinyae and T. rex, they may have served a purpose, according to Makovicky.

Another Dinosaur with Short Arms

Another Dinosaur with Short Arms

Scientists still don’t know what that purpose may have been. But theropods—a group of two-legged, flesh-eating dinosaurs—have been known to have forelimbs of questionable utility, Popular Science noted.

“There are a lot of different groups of theropods that tend to reduce the size of their hands and their arms or change the way that they’re used,” Lindsay Zanno, head of the North Carolina Museum of Natural Sciences’ Paleontology Research Lab who was not involved in the study, told The Christian Science Monitor.

“We don’t actually know what would have triggered a reduction in the forelimb in each individual lineage,” Makovicky told The New York Times. “But obviously there was some adaptive advantage because we see it multiple times in different lineages of theropods.”

Citation: Article  By Alison F. Takemura

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WFS News: Dinosaur tail complete with its feathers trapped in a piece of amber

Researchers from China, Canada, and the University of Bristol have discovered a dinosaur tail complete with its feathers trapped in a piece of amber.The finding reported today in Current Biology helps to fill in details of the dinosaurs’ feather structure and evolution, which can’t be surmised from fossil evidence.

Photomicrographs and SR X-Ray μCT Reconstructions of DIP-V-15103 (A) Dorsolateral overview. (B) Ventrolateral overview with decay products (bubbles in foreground, staining to lower right). (C) Caudal exposure of tail showing darker dorsal plumage (top), milky amber, and exposed carbon film around vertebrae (center). (D–H) Reconstructions focusing on dorsolateral, detailed dorsal, ventrolateral, detailed ventral, and detailed lateral aspects of tail, respectively. Arrowheads in (A) and (D) mark rachis of feather featured in Figure 4A. Asterisks in (A) and (C) indicate carbonized film (soft tissue) exposure. Arrows in (B) and (E)–(G) indicate shared landmark, plus bubbles exaggerating rachis dimensions; brackets in (G) and (H) delineate two vertebrae with clear transverse expansion and curvature of tail at articulation. Abbreviations for feather rachises: d, dorsal; dl, dorsalmost lateral; vl, ventralmost lateral; v, ventral. Scale bars, 5 mm in (A), (B), (D), and (F) and 2 mm in (C), (E), (G), and (H). See also Figure S2.

Photomicrographs and SR X-Ray μCT Reconstructions of DIP-V-15103
(A) Dorsolateral overview.
(B) Ventrolateral overview with decay products (bubbles in foreground, staining to lower right).
(C) Caudal exposure of tail showing darker dorsal plumage (top), milky amber, and exposed carbon film around vertebrae (center).
(D–H) Reconstructions focusing on dorsolateral, detailed dorsal, ventrolateral, detailed ventral, and detailed lateral aspects of tail, respectively.
Arrowheads in (A) and (D) mark rachis of feather featured in Figure 4A. Asterisks in (A) and (C) indicate carbonized film (soft tissue) exposure. Arrows in (B) and (E)–(G) indicate shared landmark, plus bubbles exaggerating rachis dimensions; brackets in (G) and (H) delineate two vertebrae with clear transverse expansion and curvature of tail at articulation. Abbreviations for feather rachises: d, dorsal; dl, dorsalmost lateral; vl, ventralmost lateral; v, ventral. Scale bars, 5 mm in (A), (B), (D), and (F) and 2 mm in (C), (E), (G), and (H). See also Figure S2.

While the feathers aren’t the first to be found in amber, earlier specimens have been difficult to definitively link to their source animal, the researchers say.WFS News:Ryan McKellar, from the Royal Saskatchewan Museum in Canada, said: “The new material preserves a tail consisting of eight vertebrae from a juvenile; these are surrounded by feathers that are preserved in 3D and with microscopic detail.

“We can be sure of the source because the vertebrae are not fused into a rod or pygostyle as in modern birds and their closest relatives. Instead, the tail is long and flexible, with keels of feathers running down each side. In other words, the feathers definitely are those of a dinosaur not a prehistoric bird.”

SR μ-XFI Maps and Scanning Electron Micrographs of DIP-V-15103 (A) Elemental maps and region of interest (ROI) image for exposed soft tissue preservation in DIP-V-15103; black carbon film surrounds clay minerals infilling void between vertebrae or partially replacing them; milky amber related to decay surrounds vertebrae and plumage (ROI prior to clay flake removal is better visible in Figure S3H). (B) Patchy keratin preservation with traces of fibrous structure in DIP-V-15103 ventral feather. (C) Fibrous keratin sheets and isolated melanosomes from barb of modern Indian peafowl (Pavo cristatus; Galliformes). Scale bars, 2 mm in (A) and 1 μm in (B) and (C). See also Figure S3.

SR μ-XFI Maps and Scanning Electron Micrographs of DIP-V-15103
(A) Elemental maps and region of interest (ROI) image for exposed soft tissue preservation in DIP-V-15103; black carbon film surrounds clay minerals infilling void between vertebrae or partially replacing them; milky amber related to decay surrounds vertebrae and plumage (ROI prior to clay flake removal is better visible in Figure S3H).
(B) Patchy keratin preservation with traces of fibrous structure in DIP-V-15103 ventral feather.
(C) Fibrous keratin sheets and isolated melanosomes from barb of modern Indian peafowl (Pavo cristatus; Galliformes).Scale bars, 2 mm in (A) and 1 μm in (B) and (C). See also Figure S3.

The study’s first author Lida Xing from the China University of Geosciences in Beijing discovered the remarkable specimen at an amber market in Myitkyina, Myanmar in 2015.

The amber piece was originally seen as some kind of plant inclusion and destined to become a curiosity or piece of jewellery, but Xing recognized its potential scientific importance and suggested the Dexu Institute of Palaeontology buy the specimen.

The researchers say the specimen represents the feathered tail of a theropod preserved in mid-Cretaceous amber about 99 million years ago. While it was initially difficult to make out details of the amber inclusion, Xing and his colleagues relied on CT scanning and microscopic observations to get a closer look.

Photomicrographs of DIP-V-15103 Plumage (A) Pale ventral feather in transmitted light (arrow indicates rachis apex). (B) Dark-field image of (A), highlighting structure and visible color. (C) Dark dorsal feather in transmitted light, apex toward bottom of image. (D) Base of ventral feather (arrow) with weakly developed rachis. (E) Pigment distribution and microstructure of barbules in (C), with white lines pointing to pigmented regions of barbules. (F–H) Barbule structure variation and pigmentation, among barbs, and ‘rachis’ with rachidial barbules (near arrows); images from apical, mid-feather, and basal positions respectively. Scale bars, 1 mm in (A), 0.5 mm in (B)–(E), and 0.25 mm in (F)–(H). See also Figure S4.

Photomicrographs of DIP-V-15103 Plumage
(A) Pale ventral feather in transmitted light (arrow indicates rachis apex).
(B) Dark-field image of (A), highlighting structure and visible color.
(C) Dark dorsal feather in transmitted light, apex toward bottom of image.
(D) Base of ventral feather (arrow) with weakly developed rachis.
(E) Pigment distribution and microstructure of barbules in (C), with white lines pointing to pigmented regions of barbules.
(F–H) Barbule structure variation and pigmentation, among barbs, and ‘rachis’ with rachidial barbules (near arrows); images from apical, mid-feather, and basal positions respectively.
Scale bars, 1 mm in (A), 0.5 mm in (B)–(E), and 0.25 mm in (F)–(H). See also Figure S4.

The feathers suggest the tail had a chestnut-brown upper surface and a pale or white underside. The specimen also offers insight into feather evolution. The feathers lack a well-developed central shaft or rachis. Their structure suggests that the two finest tiers of branching in modern feathers, known as barbs and barbules, arose before a rachis formed.

Professor Mike Benton from the School of Earth Sciences at the University of Bristol, added: “It’s amazing to see all the details of a dinosaur tail — the bones, flesh, skin, and feathers — and to imagine how this little fellow got his tail caught in the resin, and then presumably died because he could not wrestle free.

“There’s no thought that dinosaurs could shed their tails, as some lizards do today.”

DIP-V-15103 Structural Overview and Feather Evolutionary-Developmental Model Fit (A and B) Overview of largest and most planar feather on tail (dorsal series, anterior end), with matching interpretive diagram of barbs and barbules. Barbules are omitted on upper side and on one barb section (near black arrow) to show rachidial barbules and structure; white arrow indicates follicle. (C) Evolutionary-developmental model and placement of new amber specimen. Brown denotes calamus, blue denotes barb ramus, red denotes barbule, and purple denotes rachis [as in 5, 12]. Scale bars, 1 mm in (A) and (B).

DIP-V-15103 Structural Overview and Feather Evolutionary-Developmental Model Fit
(A and B) Overview of largest and most planar feather on tail (dorsal series, anterior end), with matching interpretive diagram of barbs and barbules. Barbules are omitted on upper side and on one barb section (near black arrow) to show rachidial barbules and structure; white arrow indicates follicle.
(C) Evolutionary-developmental model and placement of new amber specimen. Brown denotes calamus, blue denotes barb ramus, red denotes barbule, and purple denotes rachis [as in 5, 12].
Scale bars, 1 mm in (A) and (B).

The researchers also examined the chemistry of the tail inclusion where it was exposed at the surface of the amber. The analysis shows that the soft tissue layer around the bones retained traces of ferrous iron, a relic left over from haemoglobin that was also trapped in the sample.The findings show the value of amber as a supplement to the fossil record. Ryan McKellar added: “Amber pieces preserve tiny snapshots of ancient ecosystems, but they record microscopic details, three-dimensional arrangements, and labile tissues that are difficult to study in other settings.

“This is a new source of information that is worth researching with intensity, and protecting as a fossil resource.”

The researchers say they are now “eager to see how additional finds from this region will reshape our understanding of plumage and soft tissues in dinosaurs and other vertebrates.”

Citation:Lida Xing, Ryan C. McKellar, Xing Xu, Gang Li, Ming Bai, W. Scott Persons IV, Tetsuto Miyashita, Michael J. Benton, Jianping Zhang, Alexander P. Wolfe, Qiru Yi, Kuowei Tseng, Hao Ran, Philip J. Currie. A Feathered Dinosaur Tail with Primitive Plumage Trapped in Mid-Cretaceous Amber. Current Biology, 2016; DOI: 10.1016/j.cub.2016.10.008

Key: WFS,World Fossil Society,Riffin T Sajeev,Russel T Sajeev

WFS News: Popcorn-rocks solve the mystery of the magma chambers

Since the 18th century, geologists have struggled to explain how big magma chambers form in Earth’s crust. In particular, it has been difficult to explain where the surrounding rock goes when the magma intrudes. Now a team of researchers from Uppsala University and the Goethe University in Frankfurt have found the missing rocks — and they look nothing like what they expected.

Researchers have previously proposed that the roofs and walls of magma chamber were either melted and assimilated into the magma, or that they would sink to the bottom of the magma chamber. However, enough evidence for either of these hypotheses have not been forthcoming, and researchers now propose a third possibility.

When rock fragments fall into the magma chamber, all fluids inside boil instantly. This is similar to what happens when a grain of corn turns into popcorn. Credit: Börje Dahrén

When rock fragments fall into the magma chamber, all fluids inside boil instantly. This is similar to what happens when a grain of corn turns into popcorn. Credit: Börje Dahrén

“We show that rock fragments from the roof of the magma chambers could have been expelled, similar to popcorn that is thrown out of a hot pan! We have found them in rocks that have been ejected in volcanic eruptions. The rock fragments are full of bubbles and have very low densities, and they look a lot like popcorn,” says Steffi Burchardt, researcher at the Department of Earth Sciences, Uppsala University.

When rock fragments fall into the magma chamber, they are rapidly heated by several hundred degrees, and all fluids inside boil instantly. This is similar to what happens when a grain of corn is put into the pan and the water inside boils — and we get popcorn.

Appearance and structure of examples of frothy xenolith fragments.

Appearance and structure of examples of frothy xenolith fragments.

Steffi and her colleagues have now managed to show how the popcorn-effect makes the rock fragments float and rise to the top of magma chambers rather than sink to the bottom. The floating rock fragments are then found among the erupted volcanic rocks, instead of inside the frozen magma chambers as previously expected. Furthermore, the gases released from the rock fragments as they boil also contribute to a higher pressure in the magma which can help explain some of the more explosive eruptions.

Appearance and structure of a frothy sandstone xenolith sample from the 2011 offshore eruption at El Hierro, Canary Islands, Spain

Appearance and structure of a frothy sandstone xenolith sample from the 2011 offshore eruption at El Hierro, Canary Islands, Spain

“Sometimes you can find the solution to age-old puzzles by looking in new places — in this case literally looking outside the box! The frozen magma chambers proved to be the wrong place to look,” Steffi explains.

Model results of thermomechanical processes associated with a xenolith sinking in a granitic magma chamber.

Model results of thermomechanical processes associated with a xenolith sinking in a granitic magma chamber.

Journal Reference:Steffi Burchardt, Valentin R. Troll, Harro Schmeling, Hemin Koyi, Lara Blythe. Erupted frothy xenoliths may explain lack of country-rock fragments in plutons. Scientific Reports, 2016; 6: 34566 DOI: 10.1038/srep34566

Citation:Uppsala Universitet. “Popcorn-rocks solve the mystery of the magma chambers.” ScienceDaily. ScienceDaily, 2 November 2016. <www.sciencedaily.com/releases/2016/11/161102080013.htm>.

Key:WFS,World Fossil Society,Riffin T Sajeev,Russel T sajeev