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When And How Did Dinosaurs Go Extinct?

Saturday, October 20, 2018

It's asteroid versus volcano.

For 165 million years, dinosaurs dominated land, sea, and sky. Long-necked Brachiosauruses lumbered along like mobile four-story buildings. Tyrannosaurus rex chased down prey with 50 to 60 teeth as big as bananas. Mosasaurs stretching 55 feet from snout to tail terrorized the seas, consuming everything they could catch.

But 66 million years ago, the world’s climate drastically changed. Dinosaurs had thrived in the warm temperatures and mild weather of the Mesozoic era. All of a sudden, the Earth became much colder and darker. Plants died and food became scarce. All the dinosaurs—except for the ancestors of modern birds—and three quarters of the creatures living on Earth went extinct.

To this day, scientists debate what caused this sudden change. The leading theories involve an asteroid strike and a giant volcano.

Both theories start with a rare metal called iridium. This element is extremely rare on our planet’s surface, but does exist in Earth’s liquid core and in space rocks like asteroids. In the rock underneath the Earth’s oceans and continents, there’s a thin iridium layer in what geologists call the K-T Boundary, or the point in the geologic record where they see evidence of the dinosaurs’ mass extinction.

Discovering this layer led scientists to speculate that a giant, six-mile-wide meteor hit the Earth around 66 million years ago. The impact had the force of 10 billion nuclear bombs and would have thrown massive clouds of iridium dust and other debris into the air, blocking out the sunlight for years.

Researchers discovered an enormous crater in the Yucatan Peninsula in Mexico that may have been in just the right spot to cause maximum destruction, as the rocks in this area may have been especially rich in carbon dioxide and sulfur or hydrocarbons, all of which could have been released into the air upon impact and contributed to the rapid shift in the climate. The crater was also around 66 million years old. Scientists found some other strange clues in the ancient layers: shocked quartz, rock that looks like a massive shockwave rearranged its crystals; soot that suggested widespread wildfires; and glass-like spheres that looked like cooled molten rock.

While many scientists think a giant fireball signaled the end for the dinosaurs, not everyone is convinced. Some say the iridium layer and the strange rock clues could also point to volcanic activity instead.

Volcanoes went wild during the last 40 million years of the dinosaurs’ reign. In what is now western India, giant cones belched lava drawn up from the Earth’s mantle, spewing dust and ash. After millions of years of eruptions, scientists reason there could have been enough debris in the air to block out the sun. The volcanoes also could have drawn iridium from deep within the Earth to form the thin layer we see in the crust today.

Some scientists argue the volcanoes would not have changed the climate drastically enough to kill all the dinosaurs. Others say the truth could be a combination of these two theories. The asteroid could even have made the eruptions worse, giving the dinosaurs a geologic one-two punch. Other scientists think the dinosaurs had already started gradually dying off before something catastrophic finished them off.

Whether by asteroid or volcano, we do know the whole planet changed suddenly and drastically. And when the darkness lifted, the surviving mammals, reptiles, and birds took over the planet.

Source: www.popsci.com

Modern Birds Might Have Dinosaur Lungs to Thank for Their Existence

Sunday, October 21, 2018

An artist's interpretation of the dinosaur-era bird Archaeorhynchus spathula, which was a bit larger than a modern pigeon. Credit: Brian Choo

Ancient organs rarely fossilize, so paleontologists were stunned to find the incredibly well-preserved remains of a lung that belonged to bird from the dinosaur age.

Initially, scientists were excited to describe the specimen of Archaeorhynchus spathula, a bird that lived about 120 million years ago, because its fossil had exquisitely preserved feathers, including a unique pintail that isn't seen in any other Cretaceous bird, but is common in birds nowadays.

A closer inspection, however, revealed that the bird's lungs had also fossilized, meaning the paleontologists had discovered the oldest "informative" fossilized lung on record (more on that later) and the oldest fossilized lung ever seen in a bird fossil, said study co-lead researcher Jingmai O'Connor, a professor with the Institute of Vertebrate Paleontology and Paleoanthropology at the Chinese Academy of Sciences.

The fossil itself is from the early Cretaceous Jehol Lagerstätte formation in northeastern China, but O'Connor and her colleagues found it at the Shandong Tianyu Museum of Nature, in Pingyi, where an avid fossil collector houses the thousands of bird fossils he's purchased over the decades.

This is the fifth described A. spathula specimen — a toothless, pigeon-size bird — but it's by far the best preserved, O'Connor said. That's especially because of the speckled, white material in its chest cavity that appears to be a fossilized lung.

The finding reveals that the lung structures in early birds are similar to the lungs of modern birds, the researchers said. This means that A. spathula likely had unidirectional airflow in its lungs — the air that flowed in was largely fresh and full of oxygen, unlike the air in mammals' lungs, which is mixed with both new and previously breathed air, meaning it has a lower oxygen content.

"Lungs of birds are very different from our lungs and [had] much more complex structures," P. Martin Sander, a paleontologist at the University of Bonn in Germany who was not involved in the research, told Live Science in an email. "They are kind of like a bag pipe, with an air management system (the air sacs) separated from the gas exchanger (the lung proper) which is preserved here."

Living crocodilians also have lungs with unidirectional airflow, and paleontologists considered it to be ancestral in early feathered dinosaurs. But evidence for such a lung structure in an early bird has been elusive, until now.

The amazingly detailed Archaeorhynchus spathula, which has preserved feathers and what may be the oldest fossil lung ever seen in a bird. Credit: Image courtesy of J. Zhang/Institute of Vertebrate Paleontology and Paleoanthropology, Beijing

Deep dive

To get a better look at the supposed lung remains, "we went and extracted some samples, put them in the SEM [scanning electron microscope] and — boom — lung tissue," O'Connor told Live Science. Because O'Connor specializes in skeletal (not organ) anatomy, she roped in John Maina, a professor of zoology at the University of Johannesburg in South Africa, who is an expert on the lungs of living birds.

"I was like, 'Look, do you think this is lung tissue? If you do think it is, then none of us digging-in-the-dirt paleontologists can argue with you,'" O'Connor said. Maina's contribution was so critical, that he became a co-researcher on the study.

An analysis of the tissue showed that it contained structures that resemble blood capillaries, which absorb oxygen to help power the highly energetic flight of birds. "Avian flight is the most physically demanding form of locomotion, so you need a lot of oxygen for it," O'Connor said. 

It's possible that this unique structure was unique to Ornithuromorpha, a clade (group) of ancient birds that survived the mass extinction about 66 million years ago and includes today's living birds. "Maybe this specialization was only in that clade and was one of the many factors that allowed [their] survival," O'Connor said.

What's more, it appears that the fossilized lung was embedded in the bird's ribs, just as bird lungs are today. Unlike human lungs, which expand with every breath, bird lungs are rigid, so they can easily inhale and exhale at the same time, O'Connor said.

The tissue doesn't appear to be leftover stomach contents, as those usually preserve as black, carbonized organic matter, she noted. Moreover, the preserved tissue is paired, just like a modern lung. There are no other paired organs that it could be, and it's likely not the liver (which is lobed) because that organ has a high iron content and usually preserves as red, O'Connor said.

However, this specimen isn't the oldest lung on record. That honor goes to Spinolestes, an early Cretaceous mammal that has fossilized lungs about 5 million years older than the newly analyzed bird. But those lung fossils didn't preserve any microstructure and don't provide much information about Spinolestes, other than that it likely had a muscular diaphragm. So, O'Connor is calling the A. spathula fossil "the first informative lung remains," because they shed light on bird evolution.

The lung findings are "cool stuff," because it shows"what the lung of an early bird looked like," Sander said. However, because it's so rare to see a fossilized organ, more work is needed to verify that this is a lung, he said.

"We should apply various other analytical techniques to confirm that the area in the fossil really is lung," he said. "But I would not be surprised if lung can fossilize because of its high iron content because the lung is rich in blood."

The research was presented here at the 78th annual Society of Vertebrate Paleontology meeting (Oct. 18, 2018).

Originally published on Live Science.

Tyrannosaurus Rex Arms May Have Been Useful After All

Sunday, October 21, 2018

A T. rex skeleton. Photo credit: Getty

Scientists have discovered Tyrannosaurus rex (T. rex) arms may have actually been useful, instead of the short stumpy implements they are currently believed to be.

The discovery hinges on the way the arms move. Scientists realised the T. rex and other predators like it may have been able to rotate their palms, LiveScience reports.

Christopher Langel, an undergraduate student of geology, and Matthew Bonnan, a professor of biology, both from Stockton University in New Jersey, made the discovery by looking at distant relatives of the T. rex - the American Alligator and domestic turkey.

The pair was forced to use other animals' legs because soft tissue rarely fossilizes, so there isn't much left of T. rex cartilage to study.

"We are missing information on what the shapes of the [theropod] joints actually looked like and how far apart the bones were when the predatory dinosaur was alive," Dr Langel told LiveScience.

They found the T. rex, and in fact all other theropods (a group of meat eating, bipedal dinosaurs) could have had a bigger range of movement than first anticipated.

It adds to the saying "T. rex was a clapper not a slapper", as it means it likely kept its hands in a clapping position with the palms facing inwards, rather than a slapping position with them facing down.

Scientists still aren't sure what it all means, but they think it would have been possible for the dinosaurs to use their arms to bring smaller prey towards their face for eating.

Dr Langel and Mr Bonnan now plan to study more turkey and alligator legs to tighten up their theory.

The pair's initial study is yet to be published in a peer reviewed journal.

Source: www.newshub.co.nz

New Research Indicates the Oldest Fossils Ever Found on Earth Might Just be Rocks

Friday, October 19, 2018

In this July 2012 photo provided by Laure Gauthiez, scientists Vickie Bennett, Allen Nutman and Clark Friend examine rocks in Greenland. A new study says what were billed as the oldest fossils on Earth may just be some rocks. Two years ago, a team of Australian scientists, including Nutman, found odd structures in Greenland that they said were partly a leftover from microbes that lived on an ancient seafloor. The tiny structures were said to be 3.7 billion years old. But different researchers concluded in a study published Wednesday, Oct. 17, 2018, that the structures were likely not fossils. The Australian scientists defended their work. Laure Gauthiez/The Australian National University via AP, File

Oldest fossils ever are probably just rocks: Study.

What were billed as the oldest fossils on Earth may just be some rocks, according to a new study.

Two years ago, a team of Australian scientists found odd structures in Greenland that they said were partly leftovers from microbes that lived on an ancient seafloor. They were said to be 3.7 billion years old, which suggests life formed quicker and easier than thought after Earth formed.

But the journal Nature, which published the 2016 study, released new research using NASA technology that concludes the structures found on rocks were likely not fossils but more rock. The Australian scientists, however, still maintain they are.

The new work was done by NASA astrobiologist Abigail Allwood, who had found the previously oldest fossil at nearly 3.5 billion years old. When she read the 2016 paper, she thought “there was something not quite right” so she went to Greenland and looked herself.

Allwood found the shapes, the weathering and mostly the interior layers of the structures didn’t fit with this type of fossil, called stromatolites. One even was growing in what she called the wrong direction.

Then Allwood used a version of an instrument that’s being sent to Mars in a few years to create a chemical map of the structure. She said it didn’t have the chemical signature of fossilized life.

Three outside experts told The Associated Press they agree with the newest research; none thought they were fossils as suggested by Allen Nutman at the University of Wollongong in Australia.

A claim of such an old fossil requires several lines of evidence, “so scientists were impressed but not convinced by Nutman’s work,” said University of Connecticut’s Pieter Visscher. He said he was persuaded by Allwood’s thorough work that it was not a fossil.

Nutman and his colleagues released a statement defending their work. They said Allwood took samples from the far end of one of two sites and didn’t test the original specimens when offered.

“This is a classic comparing apples and oranges scenario, leading to the inevitable outcome that ours and their observations do not exactly match,” they said in the statement.

Said another of the outside experts, Marie Catherine Sforna of the University of Liege in Belgium: “The search for traces of early life is without any doubt a difficult task and often raises controversy.”

Source: www.ktvb.com

This Flesh-Eating Fish 'Super-Piranha' Terrorized Jurassic Seas

Saturday, October 20, 2018

An artist’s reconstruction of Piranhamesodon pinnatomus. Image credit: Jura-Museum Eichstätt.

A remarkable new species of predatory fish that lived about 152 million years ago (Jurassic period) has been identified from a fossil found in Germany.

The ancient fish, named Piranhamesodon pinnatomus, belongs to Pycnodontiformes, an extinct order of ray-finned fishes that lived from Triassic to Eocene period.

“It comes from a group of fishes that are famous for their crushing teeth,” said Dr. Martina Kölbl-Ebert, a paleontologist at the Jura-Museum Eichstätt.

“It is like finding a sheep with a snarl like a wolf.”

“But what was even more remarkable is that it was from the Jurassic.”

The nearly complete fossilized specimen of Piranhamesodon pinnatomus came from the Late Jurassic Plattenkalk deposits of the Solnhofen Archipelago, Bavaria, the same deposits that contained the famous feathered dinosaur Archaeopteryx.

Careful study of the specimen’s well-preserved jaws revealed long, pointed teeth on the exterior of the vomer, a bone forming the roof of the mouth, and at the front of both upper and lower jaws.

Additionally, there are triangular teeth with serrated cutting edges on the prearticular bones that lie along the side of the lower jaw.

The tooth pattern and shape, jaw morphology, and mechanics suggest a mouth equipped to slice flesh or fins.

“We were stunned that this fish had piranha-like teeth,” Dr. Kölbl-Ebert said.

The scientists also found the victims of Piranhamesodon pinnatomus: other fish that had apparently been nibbled on in the same limestone deposits where this piranha-like fish was found.

“We have other fish from the same locality with chunks missing from their fins,” said Dr. David Bellwood, a researcher at James Cook University.

“This is an amazing parallel with modern piranhas, which feed predominantly not on flesh but the fins of other fishes.”

paper reporting this discovery is published in the journal Current Biology.

_____

Martina Kölbl-Ebert et al. A Piranha-like Pycnodontiform Fish from the Late Jurassic.Current Biology, published online October 18, 2018; doi: 10.1016/j.cub.2018.09.013

Source: www.sci-news.com

This Juvenile Dinosaur Got Eaten, Bite Marks on Bones Reveal

Friday, October 19, 2018

A reconstruction of a young Gorgosaurus eating the ceratopsian. (Credit: Marie-Hélène Trudel-Aubry)

As heavily armored as Triceratops and its cousins often were, they were far from invulnerable. That’s apparent in a new fossil scientists have unearthed from a juvenile member of the horned dinosaurs. It’s got obvious bite marks in it that might have come from a tyrannosaur or raptor.

Paleontologists examined a fossil roughly 76.5 million years old excavated from the badlands of Dinosaur Provincial Park in Alberta, Canada. The specimen belonged to a ceratopsian, the herbivorous dinosaurs that included three-horned Triceratops and spike-frilled Styracosaurus.

Nibbling on a Frill

Specifically, the roughly 3-inch-long, half-inch-thick fossil was likely part of the bony frill of a ceratopsian known as a centrosaur.  “The big ones had skulls well over a meter long and a typical adult would have been about 6 meters in total length,” said study lead author David Hone, a paleontologist at Queen Mary University of London. “They had a big curved nose horn, only tiny brow horns and a fairly complex frill of spikes. Ecologically, they were low browsers of tough plants.”

The size and structure of the fossil suggested that it belonged to a juvenile Centrosaur. “It would have been about 4 meters long,” Hone said. “That’s pretty big, but they get much bigger.”

A number of marks on the fossil apparently came from bites. These marks do not match known bite marks from crocodilians, lizards or mammals known from this place and time. Instead, the clearest bite marks came either from the very thin, blade-like teeth of a large dromaeosaur — the feathered predators often known as raptors — or the broad, deep teeth of a young tyrannosaur.

“There are two sets of tooth marks, and these might have been made by different animals,” Hone said.

Based on the nature of the bite marks, the researchers suspect they came from a scavenger. The frill “is an area that would normally have no real muscle and only a bit of skin, so not something most predators would try and take even if they had days to feed on the rest of the body,” Hone said.

These are the first known bite marks found on the fossil of a juvenile ceratopsian, and it helps paleontologists better understand how the dinosaurs of the time interacted with each other. “Juveniles are rare generally in the fossil record, so while we think a lot of them likely got eaten and we might expect to see bites on them, because they are rare, getting evidence of bites on a non-adult is rare,” Hone said. “It’s nice confirmation that bites were not just happening on adults.”

Source: http://blogs.discovermagazine.com

Dinosaur Fossils Discovered in Inner Mongolia

Friday, October 19, 2018

The Kissing Dinosaurs of Erenhot, China

A group of dinosaur fossils has been discovered in north China's Inner Mongolia Autonomous Region.

Paleontologists found the fossils in Ejinaoer Township and have begun an excavation.

According to authorities, fossils of a giant sauropod dinosaur, believed to have existed during the early Cretaceous period 120 million years ago, have been found. The fossils are quite intact, and paleoeologists say that the dinosaur could have been as long as 17 meters.

Fossils of Archaeornithomimus dinosaurs have also been spotted.

Archaeornithomimus asiaticus skeleton mounted at the Paleozoological Museum of China.

The area has been listed as an area in urgent need of excavation and will provide valuable materials for research about sauropod dinosaurs.

Source: www.xinhuanet.com

Printing Dinosaurs: Idaho Virtualization Lab leads a “3-D revolution”

Thursday, October 18, 2018

ISU houses the Idaho Virtualization lab in the Idaho Museum of Natural History, which is on the leading edge of the 3-D printing revolution in digitizing and printing fossils, according to museum director Leif Tapanila.

The program has been going for 15 years, and Tapanila said in those years, the rest of the country has begun to recognize the value of digitizing and 3-D printing fossils

“There’s groups of museums across the country that are involved with this 3-D revolution, the idea that we can give access and discoverability to all of these hidden treasures across the country,” Tapanila said.

Jesse Pruitt, lab manager of the Idaho Virtualization Lab, said his is the only program in the country that goes to the extent it does in 3-D printing fossils.

“Everybody does a little bit of this and a little bit of that, but no one really does [everything we offer],” he said.

Other labs in the country are more research-driven, while the Idaho Virtualization Lab operates more uniquely, Pruitt said.

“We do our own internal research, we digitize our collections and we also do other people’s research as well,” he said.

Other labs generally don’t perform research for other universities, according to Pruitt.

The lab is “outpacing everybody else in the country in terms of output and quality,” Pruitt said.

It’s unusual to see a small state school house this kind of program, he added.

“It’s not something you see at a smaller university,” Pruitt said. “For this to exist at the level that it exists here is pretty remarkable in my mind.”

The Idaho Visualization Lab is also one of the only programs to have a large online database of the 3-D models it creates. The Smithsonian, one of the only online collections rivaling his lab’s, has around 200-300 models in its database, while the Idaho Visualization Lab has around 3,000 models, Pruitt said.

Museum professionals consider 3-D printing a safer process than casts and molds because there’s less of a chance of the fossil being damaged. Pruitt said there have been models the lab has made of damaged or fragile skeletons that they never would’ve been able to make a cast of because of how likely they were to break.

Another advantage to 3-D printing fossils is that they don’t have to be shipped. Any museum with access to the database can 3-D print their own fossils.

Pruitt estimates that it will take another 15-20 years for the work the lab performs to become mainstream in the rest of the country.

“3-D scanning and 3-D printing are gonna be the future of how we do this,” he said.

Tapanila said he’s thrilled to be a part of a program like this.

According to Tapanila, there are an estimated three billion historical specimens in the United States hidden away in museum collections for preservation.

“That’s three billion objects that could be used more broadly if people knew about them, could access, search, and do research on them,” he said.

The Idaho Virtualization Lab has taken the opportunity to spread knowledge about the processes it uses by educating middle schoolers in the area by building their own dinosaur at Dino Camp.

During the summer, the students were trained to use the software Pruitt and his lab use to digitize and 3-D print an oryctodromeus dinosaur, the most common dinosaur found in Idaho.

That dinosaur is now a part of the museum’s permanent collection.

“That’s the kind of transformation that this kind of technology allows us to bring to the public, to educate kids and give opportunities,” Tapanila said.

Tapanila said members of the Idaho Virtualization Lab are working hard to make their work even more available to the research community and the public.

“We’re part of that solution, of making [this research] available to people,” Tapanila said. “It’s really exciting to be a part of that.”

Source: http://isubengal.com

Experts Start New Round of Preservation Work on Dinosaur Footprints in Beijing

Thursday, October 18, 2018

An experimental conservation effort for dinosaur footprints in Yanqing Geopark in Beijing, Oct. 15

Experts from China and Greece have started a new round of joint preservation work on more than 180 fossilized dinosaur footprints discovered in a suburb of Beijing.

The team has started to clean the surface of the fossils, fill the cracks and apply a special reagent to prevent them from weather damage.

"We hope that our preservation work can make dinosaur footprints more visible and maintain their original conditions, so as to attract more visitors and enrich their knowledge about dinosaurs," said Ilias Valiakos, an expert from Greece.

The footprints, unearthed in a geological park in Yanqing County in 2011, are the first dinosaur traces to be found inside the city. They are believed to be left by dinosaurs that lived some 140 to 150 million years ago in the late Jurassic Period.

"About 120 footprints are relatively visible, with the largest ones 60 cm long and 3 cm deep," said Zeng Guangge, an administrator with the Yanqing Geopark.

The team has conducted two rounds of preservation work on these dinosaur footprints in October last year and May this year.

Source: www.globaltimes.cn

Dinosaur Theme Park To Open Soon - And Here's How To Win Free Family Entry For a Year

Thursday, October 18, 2018

A new dinosaur theme park is opening - and you can win free family access for a whole year.

The park, to be called Dinotropolis, will feature animatronic dinosaurs, three storeys of soft play, dino interactives, raptor racing and the tasty Fossil Cafe.

And it is opening at Bluewater Shopping Centre, in Kent, so not too far to travel!

A promotional website about the new theme park reads: "You’ll become a real Dino Ranger when you explore the Jurassic world in our Discovery Cove, where you can search for fossils in the Dino Dig and discover all of your favourite dinosaurs.

"Build your own volcanoes at the scientific sand table, paint and draw anything your heart desires in our arts and crafts corner and bring dinosaurs to life on our huge interactive screens. The best place to learn and play before putting your Dino Ranger skills to the test.

"Plus - when you're all played out, you can refuel like a true ranger at the Fossil Cafe, serving up deli-ceous, nutri-ceous meals and snacks. So, get ready to be catapulted back in time to a forgotten era where you will see, hear, and feel what it was really like to play with the dinosaurs!"

Any more information is being kept quiet, with no opening date released currently.

The theme park is also holding a competition to win free family access for a year.

Source: www.gazette-news.co.uk

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