Newly Discovered 250-Million-Year-Old Fierce Lizard Fossil is Named After Mythical Monster

Ancient Origins

Who knows if the people who lived in the Paraná Basin of southern Brazil years ago saw fossils of dinosaurs and came up with strange mythical beings because of them. Whatever connection there may be, scientists have identified a new fossil near where the Guarani people live—a beautiful fossil of a creature that fills an evolutionary gap.

The previously unknown lizard lived about 250 million years ago.
The scientists have named the genus of the creature after one of the Guarani people’s mythical monsters. An article in the journal Nature states:

“Genus named after Teyú Yaguá, one of the seven legendary beasts in the mythology of the Guarani ethnic group, who occupied a large territory of central east South America, including the type locality of the new species. Teyú Yaguá, literally meaning ‘fierce lizard,’ is commonly represented as a dog-headed lizard. Species name derived from paradoxa, Greek meaning ‘paradoxical’, ‘unexpected’, owing to its unusual combination of plesiomorphic and derived characters.”

Teyujagua paradoxa holotype. (Pinheiro et al.)

The team who found it, three Brazilian university researchers, call it a beautiful fossil. It was a small animal, similar to a crocodile. It likely lived near lakeshores and fed on fish.
An article on Guarani mythology describes the monster called Teyú Yaguá and says it is a giant lizard with a dog’s head and skin covered in gold and precious stones that it gained from rolling in the treasures of Itayu.
His eyes are believed to shoot fire, but despite this and his menacing appearance, he is said to be benign. He doesn’t move well, but that may be due to his large size.

Depiction of Teyú Yaguá from the Mythical Museum Ramón Elías. (tripfreakz)

According to legends, Teyú Yaguá’s diet consists of fruit, and he is considered the protector of fruits. But his favorite food is honey, which his brother Yasy Yatere, another monster, gave him.

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Not knowing about evolution led many people around the world to tell stories about how the world and its various creatures and features came into being. The Guarani believed that Teyú Yaguá was the son of Tau, the spirit of evil, and Kerana, a Guarani princess.
The couple’s story is highly important in the Guarani creation myth and belief system. Tau took form as a human and courted Kerana for seven days.

Depiction of Tau and Kerana. (Public Domain)

But the spirit of good, Angatupyry, tried to save Kerana. Angatypyry fought Tau for seven days until he defeated him. Tau went into exile. But he returned, kidnapped Kerana, and they became a couple. The goddess Arasy cursed the couple. With this curse and Tau’s malevolent nature, the pair had seven monstrous sons with different attributes and domains. Teyú Yaguá is one of these seven sons.
The fossil identified by the scientists from Brazilian universities was related to the dinosaurs’ ancestors the archosauriforms—a class of reptiles that were at the apex of the food chain before a series of volcanic eruptions nearly wiped them out about 252 million years ago. About 90 percent of Earth’s life forms that lived then were killed by the catastrophe.

Fossilized skull of the Teyujagua. (University of Birmingham)

Felipe Pinheiro of the Universidade Federal do Pampa was one of the scientists who discovered the fossil skull near the city of São Francisco de Assis.

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He said the creature differs from other fossils of the Lower Jurassic. It is similar in anatomy to the archosauriforms and primitive reptiles, including the dinosaurs and pterosaurs, modern birds and crocodiles.
"The discovery of Teyujagua was really exciting,” Pinheiro told the BBC. “Ever since we saw that beautiful skull for the first time in the field, still mostly covered by rock, we knew we had something extraordinary in our hands. Back in the lab, after slowly exposing the bones, the fossil exceeded our expectations. It had a combination of features never seen before, indicating the unique position of Teyujagua in the evolutionary tree of an important group of vertebrates.”

Archosauromorph phylogeny showing the recovered position of Teyujagua. (Pinheiro et al.)

The ancient culture of the Guarani people, who are spread across Paraguay, Brazil, Argentina, and Bolivia, is as strong today as it was many centuries ago, sustained through an oral tradition of passing down myths and legends from one generation to the next.
Featured Image: Artistic representation of Teyujagua paradoxa. Source: Voltaire Neto
By Mark Miller

Dinos Issued a Climate Warning 215M Years Ago

Sauropods avoided volatile tropics in Triassic

Only small, carnivorous dinosaurs could have survived these conditions, a study finds.   (Victor Leshyk

 

Newser

 Scientists have long been baffled by a lack of Triassic period fossils from large, herbivorous dinosaurs known as sauropods near the equator. A new study offers some illumination: It suggests a hot, unpredictable climate and high carbon dioxide levels kept some of the world's first dinosaurs away—and may shed light on our own issues with climate change. Researchers first analyzed ancient sedimentary rocks in New Mexico, which would have been much closer to the equator as part of the supercontinent Pangea some 215 million years ago, reports LiveScience. In separating carbon isotopes from fossilized organic matter, they identified significant and rapid changes to the ecosystem and atmospheric CO2 levels—which were four to six times those of today. Pollen and spores suggested available plants varied in quantity based on the frequent changes, while fossil charcoal showed evidence of wildfires every few dozen years that wreaked havoc on vegetation.                                                                

The combined factors suggest an environment too unstable for sauropods until about 30 million years later, though small, carnivorous dinosaurs did populate the area. "The conditions would have been something similar to the arid Western United States today, although there would have been trees and smaller plants near streams and rivers and forests during humid times," study author Jessica Whiteside explains in a press release. Eerily, she writes at the Conversation that "rapid climate swings and extremes of drought and intense heat driven by increasing atmospheric CO2 levels have as much ability to alter the vegetation supporting modern human populations as they did for the large plant-eating dinosaurs in the Triassic." Whiteside adds we can expect "profound challenges to human sustainability in the future if we experience the high CO2 conditions predicted to develop in the coming 100 to 200 years." (Scientists made an incredible discovery inside "crap" dino fossils.)

Toxic oceans played a huge part in prehistoric mass extinction

 Walt Bonner

Fox News

 

A woman looks up at a replica skeleton during a preparation for an exhibition titled "The Dawn of the Dinosaurs", displaying fossils, replicas of the creatures and skeletons from the Triassic age, at Roppongi Hills in Tokyo July 2, 2010. (REUTERS/Yuriko Nakao)

An oxygen-depleted ocean played a huge role in the prehistoric mass-extinction that occurred at the end of the Triassic Period, new research revealed. According to a study to be published in Geology, changes in the biochemical balance of the Panathalassic Ocean– one of two oceans that surrounded the supercontinent Pangea – were a critical factor in the extinction where half of the Earth’s animal, plant, and marine life died.

The Triassic period saw the emergence of dinosaurs, who became the dominant animal life form during the subsequent Jurassic period.

 

“This is significant because it is the first time an open ocean setting was investigated,” Study Co-author Jessica Whiteside of the University of Southampton in the U.K., told FoxNews.com. “Previous work focused on shallow coastal areas in what is now Europe, where regional effects could predominate. Thus, by studying the Panathalassic Ocean, we provided strong evidence that these environmental changes were global in nature.”
When Pangea broke apart 201 million years ago, volcanic rifts spewed massive amounts of carbon dioxide into the atmosphere. While this created a rise in temperatures from the greenhouse effect, the huge spike in carbon dioxide brought about a massive chemical bio-imbalance in the Earth’s oceans. When the oceans’ surface waters that were exposed to the sun (the photic zone) lost oxygen, they became toxic by way of hydrogen sulfide – an extremely poisonous chemical produced by microorganisms that don’t need oxygen to survive. This process is called photic zone euxinia (PZE).
To find rocks that lay at the bottom of the Panathalassic Ocean during this period, the researchers travelled to the Queen Charlotte Islands off the coast of British Columbia, Canada. “We of course did not know if the Canadian rocks would contain evidence of PZE, only that they were deposited in well-mixed and rather deep oceanic waters of the Panathalassic Ocean, in contrast to earlier studies that [focused on] terrestrial and very shallow marine sediments,” Whiteside told FoxNews.com. “We wanted to test the hypothesis that PZE was more widespread than just the shallow marine environment, and therefore of potential global, rather than local, significance.” The team knew that if there was evidence of PZE, the rocks were comprised of the right sediment to preserve the indicative molecules.

To find these molecules, which are so small they couldn’t even be seen under a light microscope, the team had to take the sediment samples to a lab. After chemically isolating the fossilized organic cells from the sediment in the lab, Whiteside and her colleagues measured the molecules (or biomarkers) from the cells’ fat membranes.
“In their structural formulae, these molecules record environmental conditions,” Whiteside explained. “Because we know how they affect the environment today, and how the environment affects them, we can infer what happened in the geologic past if we know their concentrations.” For example, the researchers knew that the presence of green sulfur bacteria today indicates an environment where there is light and hydrogen sulfide, but little oxygen (green sulfur bacteria is found in volcanic hot springs, salt marsh sediments, and in the depths of freshwater lakes). As noted earlier, hydrogen sulfide is a by-product of anaerobic organisms and is extremely toxic to most forms of life.
“Thus,” concluded Whiteside, “if we find biomarker evidence for green sulfur bacteria in the geologic record, we can infer that oxygen is depleted and levels of hydrogen sulfide also increased during that time. Our study demonstrates that for the mass extinction 201 million years ago, hydrogen sulfide poisoning disrupted the distribution of nutrients and altered food chains essential for the survival of marine ecosystems in the area. All this, from tiny bits of fat.”
She notes it took dozens of thousands of years for the rise in carbon dioxide and greenhouse gases to bring about the mass extinction, which on a geologic timescale is nearly instantaneous.
Though there were no polar ice caps at the end of the Triassic– and the carbon dioxide levels were higher– Whiteside warns that it bears a strong resemblance to the world we live in today, thanks to the burning of fossil fuels. “The amount of CO2 released during the extinction, and the speed at which it was released, is very similar to what is occurring today, and thus serves as a cautionary tale for what might be in store for us in the near future.”

Found in Michigan backyard: 42 mastodon bones

By John Johnson

Fox News

Ancient mastodon vertebrae bones that Dan LaPoint unearthed excavating a pond on Eric Witzke's property outside Olivet, in Bellevue Township, Mich. (AP Photo/The State Journal, Rod Sanford)

Eric Witzke's home is in Bellevue Township, Michigan, but he is clearly not the first one to roam his yard. While he and neighbor Daniel LaPoint were excavating a backyard pond, they happened upon more than 40 mastodon bones, reports ABC News.

An expert from the University of Michigan Museum of Paleontology confirmed the find and says the bones are from a male mastodon, about age 40, that lived between 10,000 and 14,000 years ago, reports the Lansing State Journal.

The two unexpected archaeologists plan to donate the Ice Age bones to the museum. "Finding them was very, very cool," says LaPoint, while the museum official is happy about the "the new perspective, the new information, that specimens like these can bring." It's not uncommon for bones from the elephant ancestor to turn up in various parts of Michigan, though sometimes the discovery is of a single tusk.

In Alaska, meanwhile, the study of mastodon teeth has solved a longstanding puzzle, reports Alaska Dispatch News. Carbon dating had suggested that mastodons roamed Alaska between 10,000 and 75,000 years ago, but that never quite made sense: Alaska had few trees then and mastodons had teeth tailor-made for chomping wood.

The new study of tooth enamel shows that mastodons were in the region much earlier, about 120,000 years ago, when trees were more plentiful. (A newly discovered fossil reveals that Scotland once had something akin to a sea monster.)

This article originally appeared on Newser: Michigan Neighbors Unearth Mastodon Bones in Backyard

Bizarre dinosaur reconstructed after 50 years of wild speculation

Ian Sample

A reconstruction of the dinosaur Deinocheirus mirificus. Photograph: Yuong-Nam Lee/KIGAM

Deinocheirus mirificus, or ‘unusual horrible hand’, had long, clawed forearms, a sail on its back and
 a duck-like bill

Nearly 50 years after researchers uncovered the gigantic arms of a mysterious dinosaur in the Gobi desert, the true nature of the beast has finally been established.
Since its discovery in 1965, the only clues to the engimatic creature were its shoulders and forelimbs – the latter measuring an astounding 2.4 metres long – and a few ribs and vertebrae dug from the ground by a joint Polish-Mongolian expedition.
The fossils were extraordinary enough for scientists to declare the dinosaur a new genus and species. The name they decided upon was Deinocheirus mirificus, meaning “unusual horrible hand”.
In the absence of more complete remains, early reconstructions were at times wildly speculative. In 1970, one palaeontologist argued that Deinocheirus was a giant sloth-like climber that hung beneath the branches of enormous trees. A more accurate view put the dinosaur in a group of beaked omnivores called ornithomimosaurs, which resembled giant ostriches, at least superficially.

Deinocheirus walking. One of the newly discovered specimens was 11 metres long and weighed more than six tonnes. Video: Yuong-Nam Lee/KIGAM

But writing in the journal Nature on Wednesday , a Korean-led team of experts has transformed scientists’ understanding of the animal. They report the discovery of two nearly complete 70 million-year-old Deinocheirus skeletons, pieced together from fossils unearthed in Mongolia, along with a skull and hand that had been poached and sold on to private collectors.
With the new remains, the researchers built the first accurate reconstruction of the dinosaur. The creature stood tall on its back legs, but sported long, clawed forearms. Neural spines formed an impressive sail on its back and its long, toothless snout flared out to both sides. The duck-like bill may have helped Deinocheirus forage for food at the bottom of streams, while blunt, flattened bones under its claws prevented it from sinking on wet ground.
One of the new specimens grew to 11 metres long and weighed more than six tonnes. Its broad hips and large feet suggest it was not agile. The animal likely fed on plants and small animals, though the remains of fish were found among its stomach contents.

An artist’s impression of the dinosaur Deinocheirus mirificus. Photograph: Yuong-Nam Lee/KIGAM

Writing in the journal, Young-Nam Lee at the Korea Institute of Geoscience and Mineral Resources, describes the team’s surprise on seeing the complete dinosaur. “The discovery of the original specimen almost half a century ago suggested that this was an unusual dinosaur, but did not prepare us for how distinctive Deinocheirus is – a true cautionary tale in predicting body forms from partial skeletons,” he says.The Guardian

Newfound South American Predator Snacked on Little Dinosaurs

by Charles Q. Choi  

The predatory dinosaur Tachiraptor admirabilis, unearthed in Venezuela, attacking the herbivorous dinosaur Laquintasaura. Credit: Maurílio Oliveira

A puma-sized predatory dinosaur that may have snacked on its smaller cousins while stomping about an ancient rift valley dotted with erupting volcanoes has been discovered in Venezuela. The finding could shed light on the evolution of all carnivorous dinosaurs, researchers say.
The newfound fossil, from a dinosaur named Tachiraptor admirabilis, was unearthed from the northernmost branch of the Andes Mountains at the western border of Venezuela. The only bones from the dinosaur found so far are its shinbone and part of its hip bone, but these are enough to reveal that the beast was relatively small compared with its later, giant relatives, measuring about 4.9 to 6.5 feet (1.5 to 2 meters) long.
This two-legged species is the first predatory dinosaur unearthed in Venezuela. Its name derives from three sources: Táchira, the Venezuelan state where the fossil was discovered; raptor, Latin for thief, referring to the dinosaur's probable predatory habits; and "admirabilis," for Simón Bolívar's Admirable Campaign, which freed Venezuela from Spanish control, and in which La Grita, the town close to where the bones were found, played a strategic role. The fossils were discovered in early 2013, "near where a road was cut out of La Grita," said lead study author Max Langer, a vertebrate paleontologist at the University of São Paulo in Brazil. [See Images of an Omnivorous Dinosaur from Venezuela]
The fossils are about 200 million years old. This means the animal lived during the earliest part of the Jurassic period, when dinosaurs were beginning their rise to global dominance.
Dinosaurs originated about 230 million years ago, in the late Triassic period, but their reign began after the end-Triassic mass extinction event. One of the big five mass extinctions to affect life on Earth, this event killed off a number of other reptile groups that might have been competitors, along with at least half of all species the living on Earth. The most recent extinction event, the end-Cretaceous, occurred about 67 million years ago and ended the age of dinosaurs.
Back when Tachiraptor was alive, Venezuela was part of the supercontinent Pangaea, where most of the landmasses that make up today's continents were once concentrated.
"Pangaea was in the process of breaking up back then," Langer told Live Science. This area was a rift valley, a valley created by the rifting of the land, "like what we have in East Africa now, a rift that ultimately created the northern Atlantic Ocean," Langer said. "There was a lot of volcanic activity around, and in the valley, [there was] a meandering river, along which were patches of forest where this dinosaur lived."
Dinosaur skeletons are nearly unknown from northern South America. The only other dinosaur found in Venezuela is the two-legged, fox-sized plant-eater Laquintasaura venezuelae.
"Laquintasaura may have been part of Tachiraptor's diet," Langer said. "Tachiraptor was probably a generalist predator that ate anything it could get, such as small dinosaurs and other vertebrates, such as lizards."
Nearly all predatory dinosaurs, or theropods, belonged to a group of dinosaurs known as Averostra. This included tyrannosaurs and the ancestors of birds. However, features of T. admirabilis' shinbone revealed that it belonged to a sister group of Averostra.
"By having other theropods to compare Averostra to, it helps us understand more about Averostra and how that large group evolved," Langer said.
The find also suggests the equatorial belt of Pangaea may have played a pivotal role in theropod evolution. Past research suggested that the region was too inhospitable for dinosaurs during the early Jurassic.
"Pangaea was a sort of boomerang shape, and this dinosaur came from its equatorial warm belt, which more or less included northern South America, southern North America and Africa," Langer said. "To the north and south of this belt, you had big deserts. These findings suggest this area may not have been as barren as before thought, but may have hosted more diversity than the fossil record currently indicates."
The scientists plan to go back to Venezuela to search for more dinosaur bones; they also plan to dig in rocks of similar age in Tanzania and Brazil to learn more about the spread of dinosaurs across the world.

Live Science

Dinosaur Arms to Bird Wings: It's All in the Wrist

by Stuart Gary

One of the last niggling doubts about the link between dinosaurs and birds may be settled by a new study that shows how bird wrists evolved from those of their dinosaur predecessors.
The study, reported in the Journal PLOS Biology, shows how nine dinosaurian wrist bones were reduced over millions of years of evolution to just four wrist bones in modern day birds.
"This discovery clarifies how dinosaur arms became bird wings," said one of the study's authors, Dr Alexander Vargas of the University of Chile in Santiago.

A huge triceratops skeleton was found in Wyoming! Researchers are saying it's not a triceratops -- that dinosaur never existed.

               

"It shows that some bones fused, other bones disappeared, and one bone disappeared and then reappeared in evolution."
Skeletal similarities between theropod dinosaurs and birds provide some of the strongest evidence showing how birds developed from dinosaurs. But the evolution of straight dinosaur wrists into hyperflexible wrists allowing birds to fold their wings when not flying, has remained a point of contention between palaeontologists and some developmental biologists.
Among the structures in question is a half-moon shaped wrist bone called the semilunate which is found in dinosaurs and looks very similar to a wrist bone also found in birds.
The semilunate originated as two separate dinosaur bones which eventually fused into a single bone. However some developmental biologists claim it evolved as a single bone in birds, and so isn't the same bone as that found in dinosaurs.
To help settle the debate, Vargas and colleagues examined the wrist bones of dinosaur fossils in the collections from several museums, and compared them to new developmental data from seven different species of modern birds.
"We developed a new technique called whole-mount immunostaining, which allows us to observe skeleton development better than ever before, including the expression of proteins inside embryonic cartilage," said Vargas.

Modern Birds Are Really Baby Dinosaurs

The technique allowed the authors to determine that the embryonic semilunate in birds evolves as two separate cartilages which fuse into a single bone, consistent with what palaeontologists had been saying.
"These findings eliminate persistent doubts that existed over exactly how the bones of the wrist evolved, and iron out arguments about wrist development being incompatible with birds originating from dinosaurs," said Vargas.
The study also produced an interesting surprise for the research team when they discovered a wrist bone called the pisiform, which was present in early sauropod (four-legged, long-tailed, long-necked) dinosaurs, but had disappeared in later theropod (two-legged, two-armed) dinosaurs.
The authors found the pisiform had reappeared in early birds, probably as an adaptation for flight, where it allows transmission of force on the downstroke while restricting flexibility on the upstroke.
"We think the pisiform was lost when dinosaurs became bipedal," said Vargas. "Quadrupedal animals used this bone because they walk with their forelimbs, but bipedal dinosaurs no longer walked with their forelimbs and lost the bone. However they regained it when they began using their forelimbs for locomotion in flight."

Top 10 Largest Dinosaurs

This is a compelling scenario for a rare case of evolutionary reversal, said Professor Mike Archer of the University of New South Wales, who was not involved in the study.
"That's the most fascinating thing coming out of this work, because all of a sudden we're understanding how complex and yet how flexible and deliciously plastic embryological development can be," said Archer.
"There may be a gene lying around dormant and doing nothing, which suddenly gets kick-started and produces a structure that had been lost in the ancestor of the same animal."
Discovery News

Tiny Bite Marks Reveal Afterlife of an Ichthyosaur

By Megan Gannon

At least 145 million years ago, a hungry sea urchin might have left these star-shaped marks on this rib fragment of an ichthyosaur. Credit: Nature Communications, doi:10.1038/ncomms5789

When whales die, their bodies sink to the seafloor. But surprisingly few of their natural graves have ever been found.
The rare "whale falls" that have been seen by scientists aren't exactly grim pictures of death; rather, they're often teeming with life. Sharks, eels, bacteria and bone-eating "zombie worms" gather around these nutrient-rich graveyards. The number of new species discovered around whale falls in deep water suggests the carcasses can host distinct, complex ecosystems.
At a time when dinosaurs still roamed Earth and whales and other marine mammals had yet to evolve, the corpses of marine reptiles known as ichthyosaurs may have enriched the seas, according to a new study. [Image Gallery: Ancient Monsters of the Sea]
A group of scientists reports they found traces of scavenging on the bones from a fossilized "ichthyosaur fall" of the Late Jurassic Period. This 10-foot-long (3 meters) specimen was discovered during the construction of a road in 1991 in Dorset, England. (The creature is now housed at the Bristol City Museum and Art Gallery.)
Ichthyosaurs, which lived from about 245 million to 90 million years ago, were dolphin-shaped predators that gave birth to live young. The one that turned up in Dorset belonged to the genus Ophthalmosaurus, named so for the animal's freakishly big eyes.
The researchers — led by Silvia Danise of Plymouth University in the United Kingdom — found sharp, narrow grooves on the animal's rib bones, likely left by small fish that picked flesh off the ichthyosaur soon after it died. The scientists also saw star-shaped grazing marks likely left by sea urchins that flocked to the boneyard once it was covered in bacteria. The carcass then seems to have gone through a "reef stage" for several years when the bones were encrusted by animals like oysters.
Modern whale falls typically don't go through a long reef stage, partly because bone-eating worms in the genus Osedax can devour an entire whale skeleton within a few years, Danise and colleagues wrote on Sept. 10 in the journal Nature Communications. But this ichthyosaur was likely spared. Scientists currently believe Osedax worms, which were only described in 2002, evolved in the late Cretaceous Period — millions of years after this ichthyosaur met its death.
Live Science

Enormous New Dinosaur as Formidable as Its Namesake Battleship

 
At 60 tons, the newly named "Dreadnoughtus" is the most complete of the giant titanosaurs yet found.

Ken Lacovara is shown with 22 tail vertebrae (out of 32 collected) of the massive sauropod Dreadnoughtus schrani. The dinosaur has the largest calculable weight of any known land animal.

 Photograph by Robert Clark, Excel Magazine, Drexel University

Brian Switek

After nine years of excavation and study, paleontologists have unveiled one of the largest creatures ever to walk the Earth. The most complete skeleton of a giant titanosaur will provide new insights into how these giants lived large.

The new dinosaur is named Dreadnoughtus schrani, a reference to the armored battleship and a tribute to the dinosaur's perceived fearlessness. Details on the dinosaur are announced Thursday in the journal Scientific Reports.

Art: Emily M. Eng, NG Staff Source: Matthew C. Lamanna, Carnegie Museum of Natural History

In life, Dreadnoughtus would have been about 86 feet (26 meters) long and weigh nearly 60 tons, heavier than a Chieftan tank, Drexel University paleontologist Ken Lacovara and colleagues calculate. That's so big, the scientists write, that adults of the species would have been "nearly impervious to attack" by predators that stalked the same floodplains between 84 million and 66 million years ago.

Among the largest of dinosaurs, titanosaurs like Dreadnoughtus were hefty herbivores with tiny heads, long necks, and tapering tails. This body type marks titanosaurs as part of a group called sauropods, to which classic dinosaurs such as Apatosaurus also belonged. Sauropods spent their days feeding high and low, plucking greens from patches of ferns and trees alike, as they browsed the prehistoric salad bar.

What makes Dreadnoughtus a remarkable new addition to this prehistoric family is the amount of material recovered from the dinosaur. The remains, representing two individual animals, include both the humerus and femur of Dreadnoughtus, and Lacovara and colleagues used the circumference of these bones to estimate the dinosaur's weight.

So far, Lacovara says, "Dreadnoughtus has the largest calculable mass of any land animal."

The humerus, or upper arm bone, of Dreadnoughtus shows muscle scarring.

Photograph by Robert Clark, Excel Magazine, Drexel University

A Big Find

At first, though, Dreadnoughtus didn't seem so impressive. "In 2005, we were prospecting in the desert [of southern Argentina]," Lacovara says, "and the first day of that field season I found a collection of bones." They just looked like a pile of fragments, but when Lacovara and collaborators returned to the site, they started uncovering big limb bones.

"By the end of the day we had ten bones exposed," Lacovara says. "At that point we were pretty excited." Four field seasons later, the team had excavated 145 bones.

Altogether the bones represent about 45 percent of a complete skeleton, and because some of the bones have mirror images on the other side of the body, Lacovara and colleagues were able to reconstruct about 70 percent of a Dreadnoughtus skeleton. The best large titanosaur find previously, Futalognkosaurus, was only about 27 percent complete.

"Now we can start talking intelligently about the body proportions of these giant titanosaurs," says Western University of Health Sciences paleontologist Mathew Wedel.

Emily M. Eng, NG Staff

And Dreadnoughtus could have grown even bigger than the new estimate. "Since the authors provide data that illustrate that Dreadnoughtus was still growing when it died," says Macalester College paleontologist Kristi Curry Rogers, "we can be fairly certain that there were other heavier dinosaurs out there."

Mysterious Lives

But size isn't everything. "If we want to really begin to understand how these big dinosaurs grew, and how long it took them to reach their massive sizes, these are the perfect kinds of data to begin with," Curry Rogers says. Having two individuals is a good start, she says, but scientists will need to find more of the dinosaurs to begin piecing together their lifestyles.

"There are so many fundamental things we don't know about sauropods," Lacovara says, such as the arrangement of their muscles and how they moved. Turning to muscle scars on the bones of Dreadnoughtus, Lacovara and others are figuring out the dinosaur's muscle anatomy and how those soft tissues translated to movement.

This is just the sort of effort other paleontologists are hoping to see. "It's all about building toward a more complete picture of the living animal," Wedel says.

The 5.6-foot (1.7-meter) scapula of Dreadnoughtus is the longest yet reported for any titanosaur.

Photograph by Robert Clark, Excel Magazine, Drexel University

For now, though, Lacovara is glad to see Dreadnoughtus finally emerge after all the years of fieldwork and study. "This is like Christmas and my birthday and my wedding combined."

 

National Geographic

Here are some of the biggest dinosaur questions still unanswered

By Neal Colgrass

Dinosaur articles, movies, and museum displays are common enough that you might consider all dino-mysteries solved, but the Smithsonian reports that major ones still remain. Among them:

• Who was first? Nobody knows which dinosaur species came first, partly because fossil records provide fragmentary insights rather than "the entire reel," notes the Smithsonian.
  But skeletons in Tanzania and tracks in Poland tell us that dinosaurs may have started about 245 million years ago—with the slim and "dog-size" Nyasasaurus.
• Hot- or cold-blooded? Several experts say dinosaurs were hot-blooded, but now some suggest they were "mesotherms," warming their bodies with their muscle activity and experiencing changing body temperatures.
• Who was biggest? The fossil record isn't clear, but titanic sauropods evolved a few times into huge creatures like the Supersaurus, Diplodocus, and Argentinosaurus, each of which reached about 100 to 110 feet in length.
• How did they mate? Well, they hatched from eggs.
  We assume females had a cloaca—an orifice that functions for reproduction, excretion, and urination in today's crocodiles and birds—and males had an "intromittent organ" found in ostriches and ducks.
  But we can't know without clear fossils of the organs.

Click for the full list, including the mystery of their "funky headgear," hunting habits, and, of course, how they went extinct.
(Here's one theory on the latter.)
http://www.foxnews.com/science/2014/08/12/here-are-some-biggest-dinosaur-questions-still-unanswered/

Dinosaurs shrank to evolve into birds over 50m years

Ian Sample

Theropods underwent 12 stages of miniaturisation – from 163kg beasts to becoming the first birds on Earth, study finds

This is how the first feathered dinosaur, Microraptor, would have looked. It existed during the Cretaceous period, 120m years ago, in what is now northern China. Photograph: Brian Choo/Science

Huge meat-eating dinosaurs shrank steadily over 50 million years to evolve into small, flying birds, researchers say.

The branch of theropod dinosaurs which gave rise to modern birds decreased inexorably in size from 163kg beasts that roamed the land, to birds weighing less than 1kg over the period.

The radical transformation began around 200m years ago and was likely driven by a move to the trees where creatures with smaller, lighter bodies and other features, such as large eyes for 3D vision, fared better than others.

Scientists pieced together the dinosaurs' sustained shrinkage after analysing more than 1,500 anatomical features of 120 species of theropods and early birds.

The evolutionary tree reveals that the theropod ancestors of modern birds underwent 12 substantial decreases in size that led to archaeopteryx, the earliest known bird on Earth. The rate at which they evolved distinct features, such as feathers, wings and wishbones, was four times faster than adaptations in other dinosaurs.

"Birds evolved through a unique phase of sustained miniaturisation in dinosaurs," said Michael Lee at the University of Adelaide. "Being smaller and lighter in the land of giants, with rapidly evolving anatomical adaptations, provided these bird ancestors with new ecological opportunities, such as the ability to climb trees, glide and fly. Ultimately, this evolutionary flexibility helped birds survive the deadly meteorite impact which killed off all their dinosaurian cousins," he added. The study is published in the journal, Science.

The steady reduction in size saw the two-legged land-based theropods evolve new bird-like features, including shorter snouts, smaller teeth and insulating feathers.

Gareth Dyke, a vertebrate palaeontologist and co-author of the study at Southampton University said: "The dinosaurs most closely related to birds are all small, and many of them, such as the aptly named Microraptor, had some ability to climb and glide."

In an accompanying article, Michael Benton at Bristol University, said that the long-term trend that led to modern birds was probably shaped by the animals taking up in new habitats. "The crucial driver may have been a move to the trees, perhaps to escape from predation or to exploit new food resources," he writes.

A smaller body size would have benefited animals living in the trees, while enlarged eyes would improve their 3D vision to avoid collisions with branches. Insulating feathers could have helped them hunt at night, and elongated forelimbs gave them increasingly more impressive wings to enable more daring leaps from tree to tree, Benton writes

http://www.theguardian.com/science/2014/aug/01/dinosaurs-shrank-birds-theropods-earth

Tyrannosaur 'Gangs' Terrorized Ancient Landscape

By Tia Ghose

Three trackways made by tyrannosaurs have recently been unearthed in Canada. The trackways suggest the giant predators may have been pack hunters Credit: Richard McCrea

Some 70 million years ago, three tyrannosaurs stalked together across a mud flat in Canada, possibly searching for prey.
The new insight comes from several parallel tyrannosaur tracks unearthed in Canada. The dinosaur tracks provide stronger evidence for a controversial theory: That the fearsome mega-predators hunted in packs.
The ferocious beasts may have "stuck together as a pack to increase their chances of bringing down prey and individually surviving," said study co-author Richard McCrea, a curator at the Peace Region Palaeontology Center in Canada

Tyrannosaur hunting
Paleontologists have long debated whether Tyrannosaurus rex and its cousins, such as Albertosaurus, hunted alone or in groups.
While most researchers believe the predators were lone wolves, so to speak, multiple Albertosaurus specimens found in a single bone bed in Canada's Dry Island Buffalo Jump Provincial Park have led some to propose that tyrannosaurs were pack animals.
But finding groups of bones together isn't definitive evidence for pack hunting, because bones can move after death. Other circumstances can cause fossil skeletons to accumulate in one location. For instance, many carnivores wandered individually into classic predator traps, such as the La Brea tar pits in Los Angeles, but probably didn't hunt together in life, McCrea said.
Track marks unearthed
In 2011, a local hunting outfitter and guide, Aaron Fredlund, unearthed two tyrannosaur track marks in the foothills of the Canadian Rockies in British Columbia and then told McCrea's team about the discovery.
The team eventually discovered a patch 197 feet (60 meters) long by 13 feet (4 m) wide filled with footprints from multiple dinosaurs, including tyrannosaurs, other small theropods, and duck-billed dinosaurs called hadrosaurs. These dinosaurs were apparently walking in the silty sediments from an overflowing river and formed the track marks about 70 million years ago. A thick layer of volcanic ash then preserved the marks, McCrea said.
In total, the team found seven tracks that were made by three tyrannosaurs. Though the researchers couldn't identify the specific species, it's likely given the period and location where they were found that Albertosaurus, Gorgosaurus or Daspletosaurus left the tracks, McCrea said.
Though the other dinosaur tracks there are all pointing in random directions, the tyrannosaur footprints are parallel with each other. The tyrannosaurs also left prints of about the same depth in the wet sediments, suggesting they crossed through the area at the same time. (As the mud dries, the depth of footprints becomes shallower.)
The new find may be one of the world's oldest examples of a missed connection. "The hadrosaur footprints are much more shallow, indicating that they came later," possibly just a few hours or days after the tyrannosaurs, McCrea told Live Science.
Pack animals
The new tracks suggest that the tyrannosaurs may have hunted in packs to take down large prey, just as wolves do today.
"An individual wolf would not be able to take out a moose, but a pack of them would," McCrea said.
Similarly, pack hunting could explain how tyrannosaurs could kill hadrosaurs, which are almost as large as the predators, without sustaining horrific injuries, he said.
That doesn't mean tyrannosaurs would have been friendly to one another. In fact, other fossils reveal that the dinosaurs liked to head-bite each other. But the tyrannosaurs may have stuck together to hunt because it increased their odds of survival, McCrea said.
The new discovery also highlights the rough life of these hunters. One of the beasts was missing bones in its left foot, which is in keeping with many of the injuries found on other tyrannosaur specimens, McCrea said.
http://www.livescience.com/46965-tyrannosaurs-were-pack-animals.html

Did All Dinosaurs Sport Feathers? Downy Beast Suggests Yes

By Tanya Lewis

The plant-eating dinosaur Kulindadromeus zabaikalicus in its natural environment Credit: Andrey Atuchin

Steven Spielberg's "Jurassic Park" might need a little more revising — a newly discovered dinosaur species offers hints that feathers were much more common among the ancient beasts than once thought.
Researchers unearthed hundreds of fossils of a new genus and species of plant-eating dinosaur called Kulindadromeus zabaikalicus in Siberia that sports both feathers and scales. The finding suggests that most dinosaurs had feathers, which they used for insulation or attracting mates, only later relying on the fringes for flight, according to a study detailed today (July 24) in the journal Science.
"Here, for the first time, we have found featherlike structures in a dinosaur [that] is far from the lineage leading to birds," said study co-author Pascal Godefroit, a paleontologist at the Royal Belgian Institute of Natural Sciences in Belgium.

Scientists have long known that birds descended from dinosaurs. Since the mid-1990s, paleontologists in China have been finding feathered dinosaur skeletons from about 20 different groups, but they all belonged to a single lineage, theropods, which includes Tyrannosaurus rex and velociraptors. In fact, some scientists believe T. rexmay have sported some feathers itself.
Godefroit and his colleagues found hundreds of skeletons of the same species, from a lineage of plant-eating dinosaurs known as ornithischians, which lived about 160 million years ago during the middle to late Jurassic period. Researchers found the fossils buried in the bottom of what appears to have been a large lake.
"It was a small animal, not very impressive," Godefroit said. It was about 4.9 feet (1.5 meters) long; walked on two long, slender legs; and sported very short arms, he said.
The little dinosaur skeleton was equipped with preserved long filaments resembling downy feathers around its arms and legs. Because the animal couldn't fly, the scientists think these filaments may have served as insulation. The specimen also had more-complex feathers that it may have used to entice mates, Godefroit said. The animal had a long tail, covered in large, thin scales.
The preservation of soft tissues such as feathers and scales is extremely rare, the researchers said, which explains why relatively few feathered dinosaur fossils have surfaced before. "The conditions for preserving feathers are really exceptional," Godefroit said.
"This is the first time birdlike feathers have been found in dinosaurs that are not closely related to birds," said Darla Zelenitsky, a paleontologist at the University of Calgary in Canada, who was not involved in the research. "This unexpectedly reveals that such feathers would likely have been present in most groups of dinosaurs," Zelenitsky told Live Science in an email.
Steve Brusatte, a paleontologist at the University of Edinburgh in Scotland, agreed that feathers probably existed in the common ancestor of all dinosaurs. The idea is not a new one, he said; two other fossils of plant-eating dinosaurs found in China had simple, filamentlike feathers, but it was debatable whether these were related to bird feathers, or evolved independently. Now, this new evidence "seals the deal that feathers were also present in plant-eating dinosaurs," Brusatte told Live Science.
As for the fossil scales, they resemble modern birds' scales, which are actually aborted feathers, the researchers said. In chickens, for example, genes in the skin control the development of feathers. If these genes are modified, the chicken will sprout feathers on its legs, like that of an English chicken. Perhaps primitive dinosaurs had already developed this genetic mechanism of preventing feathers from developing in certain parts of their bodies, Godefroit said.
More fossils must be found in order to determine if other groups of dinosaurs besides theropods and ornithischians had feathers, the researchers said. "We found [feathered fossils] in one locality in Siberia, and we will look around now to see if we can find more," Godefroit said.
http://www.livescience.com/46991-first-feathered-plant-eating-dinosaurs.html

Stolen 'Nest of Dinosaurs' Returned to Mongolia

By Megan Gannon

Nearly 100 years ago, Mongolia made it illegal to own or export objects of cultural importance, such as dinosaur fossils. These bones were among a hoard of illegally obtained dinosaur skeletons seized by U.S. authorities. Credit: HSI

More than 18 dinosaur skeletons illegally taken from Mongolia were formally returned to their homeland last week, U.S. authorities announced.
The fossilized bones were handed over to Mongolian officials in a repatriation ceremony held July 10 in New York. "Today, we return a veritable nest of dinosaurs," Manhattan U.S. Attorney Preet Bharara said in a statement after the ceremony.     
"This is a historic event for the U.S. Attorney's Office, in addition to being a prehistoric event, and we are proud to participate in the return of these dinosaur skeletons to their rightful home," Bharara said

The road to repatriation began two years ago, in 2012, when an auction house in New York was offering a skeleton of a Tarbosaurus bataar — an Asian cousin of Tyrannosaurus rex. Mongolian authorities voiced concern that the specimen had likely been smuggled into the United States. The 70-million-year-old dinosaur species was native to the Gobi desert in Asia, and to date, has only been found in modern-day Mongolia.
The Tarbosaurus sale attracted a bid of more than $1 million, but the suspicions of the Mongolian authorities sparked a long legal battle and federal investigation. U.S. authorities froze the sale, and after a lengthy custody battle, the specimen was returned to Mongolia in May 2013.
Eric Prokopi, a self-described commercial paleontologist who imported the dinosaur, pleaded guilty to criminal charges that he smuggled the skeleton and other fossils into the United States. In June, Prokopi was sentenced to three months in federal prison.
The other Mongolian fossils forfeited by Prokopi during the case were returned in the July 10 ceremony, including a second Tarbosaurus, oviraptors and skeletons of the duckbilled, plant-eating Saurolophus angustirostris.
Federal authorities also returned fossils that had been forfeited by Christopher Moore, a onetime business partner of Prokopi in the United Kingdom, including a third Tarbosaurus, skeletons of a roosterlike Gallimimus dinosaur and a nest of fossilized eggs, all looted from Mongolia.
"The fossils returned today do not belong in the hands of any private collection or one owner," James T. Hayes Jr., special agent in charge of Homeland Security Investigations (HSI) in New York, said in a statement. "They belong to the people of Mongolia where they will be displayed in their national museum alongside the Bataar ICE repatriated last year. HSI will not allow the illicit greed of some to trump the cultural history of an entire nation."
The Mongolian government made it illegal in 1924 to own or export items of cultural significance, including dinosaur fossils.
http://www.livescience.com/46792-stolen-dinosaurs-returned-to-mongolia.html

“De los Dinosaurios a las Aves”

“De los Dinosaurios a las Aves” expone la evolución desde los primeros dinosaurios (con 225 millones de años) hasta las aves modernas, pasando por las primeras aves del Cretácico de China y de España, algo inédito en España.

    Además, los niños se podrán divertir y aprender sobre los dinosauiros y los fósiles en nuestros talleres didácticos. No te los pierdas, podrás reconocer las distintas especies de dinosaurios, identificar fósiles marinos, hacer réplicas de fósiles o excavar un dinosaurio.

    Talleres todos los días a las 19:00 h. Precio el taller 5 €.
    Visitas a la exposición todos los días de 12:00 a 22:00 h. Precio de la visita 2,50 €.

Avda. María Victoria Atencia, s/n 29010 La Píndola-Promalaga, Málaga Abierto de Domingos a Viernes Telf. 695867563 - 690146786 gaiadidactica@gmail.com
Exposición Permanente Exposiciones Temporales Visitas Guiadas Talleres Infantiles / Adultos Excursiones Culturales Cursos Campamentos Actividades Didácticas Ciclos de Conferencias
Enlace recomendado: PRODUCTOS DIETÉTICOS GRANADA Producción y venta de productos naturales en Granada, cosmética natural y productos dietéticos. Disponemos de una amplia gama de productoselaborados con propóleo, jalea real, miel, aloe vera, aceite de oliva...

http://www.gaiamuseum.es/index.html

Huge Trove of Dinosaur Footprints Discovered in Alaska

By Becky Oskin

Artist's conception of how the trace fossils were formed roughly 70 million years ago. Credit: Karen Carr/Perot Museum View full size image

A "world-class" dinosaur track site discovered in Alaska's Denali National Park shows that herds of duck-billed dinosaurs thrived under the midnight sun.
"We had mom, dad, big brother, big sister and little babies all running around together," said paleontologist Anthony Fiorillo, who is studying the dinosaur tracks. "As I like to tell the park, Denali was a family destination for millions of years, and now we've got the fossil evidence for it."
The discovery adds to Fiorillo's growing conviction that dinosaurs lived at polar latitudes year-round during the Late Cretaceous Period, about 70 million years ago

"Even back then the high latitudes were biologically productive and could support big herds of pretty big animals," said Fiorillo, curator of earth sciences at the Perot Museum of Nature and Science in Dallas.
Dino dance party
The dinosaur track site, near Cabin Peak in the park's northeast corner, has thousands of tracks from hadrosaurs, or duck-billed dinosaurs. Many of the deep tracks contain preserved skin and "nail" impressions from the plant-eating hadrosaurs.

A hadrosaur track from Denali National Park's amazing track site.
Credit: Perot Museum

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"This is definitely one of the great track sites of the world. We were so happy to find it," Fiorillo said.
Fiorillo and his collaborators also found traces from birds, clams, worms and bugs intermingled with the dinosaur tracks. Other dinosaur denizens who left behind footprints in Denali were ceratopsians, therizinosaurs and the flying reptiles called pterosaurs. Ferns and redwood cones complete the picture of a rich Cretaceous ecosystem.
The muddy ground is so rumpled by footprints that the researchers were hard-pressed to pull out tracks from individual hadrosaurs. Instead, they counted each print and grouped them by size. The results were published June 30 in the journal Geology.
There are four distinct size ranges, varying in length from 5 inches (about 12 centimeters) to 24 inches (about 60 cm). More than 80 percent of the tracks are from adults, and 13 percent are from young duckbills less than a year old. Just 3 percent are juvenile hadrosaurs. The researchers think the small number of juvenile prints suggest the young underwent a rapid growth spurt, spending only a short time as tiny, vulnerable dinosaurs (a theory also supported by studies of hadrosaur bones).
Duck-billed dinosaurs are the most common dinosaur fossils from the Late Cretaceous, with a wide range of species found on several continents. Call them the buffalo of the dinosaurs, grazing on the fern prairie and protecting their young in big herds.
Polar patrol
The evidence emerging from the Denali hadrosaur tracks show babies and juvenile dinosaurs living in Alaska during the summer. The juveniles probably couldn't endure a long migration, so the tracks suggest the dinosaurs spent their entire lives in the Arctic, rather than migrating from somewhere else, the researchers said.

Researchers document the full extent of the amazing dinosaur track site discovered in Denali National Park.
Credit: Perot Museum

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Some researchers have speculated that dinosaurs migrated north to Alaska, perhaps even coming from Canada like huge caribou herds.
"If you take a great big herd of plains eaters, they have to move at some level, otherwise they strip out all the vegetation," Fiorillo said. "But there's a growing data set that suggests they didn't do the thousand and thousands of miles of migration that was originally considered."
During the Late Cretaceous, Alaska sat at about the same latitude as today, but it was a tectonic jigsaw puzzle that had yet to assemble into today's stunning topography. Mountain-fed rivers and streams flowed through Denali, but not the same mountains: the Alaska Range was just being born. Mount McKinley, now the tallest mountain in North America, didn't exist. The climate was warmer, similar to coastal Washington and Oregon, but sunlight still flipped between extremes, with lengthy summer days and long, dark winters. [In Images: How North America Grew as a Continent]
Despite the dark winters, scientists such as Fiorillo have uncovered scores of dinosaur fossils and tracks across Alaska in recent decades, from quarries near the North Slope oil fields down to Denali's spectacular mountains.
Preserving history
Fiorillo and colleagues from Texas, Japan and Alaska have been documenting the new Denali track site since 2011. Exhibits featuring copies of the Denali dinosaur fossils and hadrosaur footprints are on display in the park and at the Perot Museum in Texas.
The trampled ground sits at the top of a steep ridge and is exposed on a cliff face about 590 feet (180 meters) long. The tracks were made within a short time range, between 69 million to 72 million years ago, likely in a muddy river or stream bank during the height of summer, the researchers said. (The bugs and plants help pin down the time of year.)
The outcrop was revealed by a rockfall and could be destroyed by another landslide in the future, so researchers scanned the area with lidar (a high-resolution laser-scanning technique) to preserve the site forever.
"On one of the last nights, as work was coming to a close, I was lying in my tent and woke up to an earthquake in the park," Fiorillo said. "For the first time in my life, I wasn't worried about a big rock [hitting me]. I was worried about my track site sliding down the mountain."
http://www.livescience.com/46688-denali-huge-dinosaur-track-site.html