Dinosaurs: New Findings & Theories

[ramonmercado]

Ancient bone-headed dinosaur found
http://www.bbc.co.uk/news/science-environment-22436942
By Helen Briggs
BBC News

Reconstruction of Acrotholus audeti

Scientists have unveiled a new species of bone-headed dinosaur, which they say is the oldest in North America, and possibly the world.

The dog-sized plant-eater had a dome-shaped skull that may have been used to head-butt other dinosaurs.

University of Toronto researchers say the new species, revealed in the journal Nature Communications, fills in gaps in the dinosaur family tree.

They believe more small dinosaurs like Acrotholus audeti await discovery.

Bone-headed dinosaurs, or thick-headed lizards, are known scientifically as pachycephalosaurs.

Continue reading the main story
“
Start Quote

We can predict that many new small dinosaur species like Acrotholus are waiting to be discovered by researchers willing to sort through the many small bones that they pick up in the field”

Dr Michael Ryan
Cleveland Museum of Natural History
They are a strange group of herbivorous dinosaurs which possessed a thick-boned dome on the top of their skulls.

The dome may have been used for decoration or to head-butt other dinosaurs in combat.

The new find, Acrotholus, dates back to 85 million years ago.

It was about the size of a large dog, weighed about 40kg (88lb), walked on two legs, and had a skull composed of solid bone over 10cm (4 inches) thick.

Dr David Evans of the Royal Ontario Museum and University of Toronto said the fossil provides a wealth of new information on the evolution of bone-headed dinosaurs.

He told BBC News: "What's interesting about Acrotholus is that it's the oldest known pachycephalosaur from North America, and it might be the oldest known pachycephalosaur in the world.

"So what Acrotholus does is it extends our knowledge of the anatomy of this group early in their evolution - and it's actually important for understanding the evolution of pachycephalosaurs in general."


The discovery is based on two skull caps unearthed from rocks known as the Milk River formation in southern Alberta
Relatively little is known about the diversity of small dinosaurs weighing less than 100kg (220lb), as they are under represented in the fossil record.

There has been scientific debate over whether the fossil record is a true reflection of the diversity of small dinosaurs or whether their more delicate bones are less likely to have been preserved compared with their larger cousins.

The Canadian study predicts the latter, suggesting there may be more discoveries of small bodied dinosaur fossils in the future.

"We can predict that many new small dinosaur species like Acrotholus are waiting to be discovered by researchers willing to sort through the many small bones that they pick up in the field," said co-researcher Dr Michael Ryan, curator of vertebrate palaeontology at the Cleveland Museum of Natural History.

 

[ramonmercado]

Gives a whole new meaning to dinosaur attitudes.

Mum and Dad Dinosaurs Shared the Work
http://www.sciencedaily.com/releases/20 ... 213109.htm

Oviraptorid skeleton and eggs in the Senckenberg Museum in Frankfurt am Main. (Credit: EvaK via Wikimedia Commons, Creative Commons license)
May 15, 2013 — A study into the brooding behaviour of birds has revealed their dinosaur ancestors shared the load when it came to incubation of eggs.

Research into the incubation behaviour of birds suggests the type of parental care carried out by their long extinct ancestors.

The study aimed to test the hypothesis that data from extant birds could be used to predict the incubation behaviour of Theropods, the group of carnivorous dinosaurs from which birds descended.

The paper, out today in Biology Letters, was co-authored by Dr Charles Deeming and Dr Marcello Ruta from the University of Lincoln's School of Life Sciences and Dr Geoff Birchard from George Mason University, Virginia.

By taking into account factors known to affect egg and clutch size in living bird species, the authors -- who started their investigation last summer at the University of Lincoln's Riseholme campus -- found that shared incubation was the ancestral incubation behaviour. Previously it had been claimed that only male Theropod dinosaurs incubated the eggs.

Dr Deeming said: "In 2009 a study in the journal Science suggested that it was males of the small carnivorous dinosaurs Troodon and Oviraptor that incubated their eggs. Irrespective of whether you accept the idea of Theropod dinosaurs sitting on eggs like birds or not, the analysis raised some concerns that we wanted to address. We decided to repeat the study with a larger data set and a better understanding of bird biology because other palaeontologists were starting to use the original results in Science in order to predict the incubation behaviour of other dinosaur species. Our analysis of the relationship between female body mass and clutch mass was interesting in its own right but also showed that it was not possible to conclude anything about incubation in extinct distant relatives of the birds."

Palaeobiologist Dr Ruta was involved in mapping the parental behaviour in modern birds on to an evolutionary tree.

Dr Ruta said: "As always in any study involving fossils, knowledge of extant organisms helps us make inferences about fossils. Fossils have a unique role in shaping our knowledge of the Tree of Life and the dynamics of evolutionary processes. However, as is the case with our study, data from living organisms may augment and refine the potential of fossil studies and may shift existing notions of the biology and behaviour of long extinct creatures."

Dr Birchard added: "The previous study was carried out to infer the type of parental care in dinosaurs that are closely related to birds. That study proposed that paternal care was present in these dinosaurs and this form of care was the ancestral condition for birds. Our new analysis based on three times as many species as in the previous study indicates that parental care cannot be inferred from simple analyses of the relationship of body size to shape, anatomy, physiologyand behaviour. Such analyses ought to take into account factors such as shared evolutionary history and maturity at hatching. However, our data does suggest that the dinosaurs used in the previous study were likely to be quite mature at birth."

The project has helped in understanding the factors affecting the evolution of incubation in birds. More importantly it is hoped that the new analysis will assist palaeontologists in their interpretation of future finds of dinosaur reproduction in the fossil record.

Share this story on Facebook, Twitter, and Google:

Other social bookmarking and sharing tools:

Share on stumbleupon Share on linkedin Share on pinterest_share Share on blogger Share on digg Share on delicious Share on newsvine |
Story Source:

The above story is reprinted from materials provided by University of Lincoln.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

Journal Reference:

G. F. Birchard, M. Ruta, D. C. Deeming. Evolution of parental incubation behaviour in dinosaurs cannot be inferred from clutch mass in birds. Biology Letters, 2013; 9 (4): 20130036 DOI: 10.1098/rsbl.2013.0036

 

[tastyintestines]

The egg came first!

 

[ramonmercado]

Fossil brain teaser: New study reveals patterns of dinosaur brain development

May 20th, 2013 in Other Sciences / Archaeology & Fossils

Fossil skull of the juvenile specimen of Dysalotosaurus lettowvorbecki. Credit: Tom Hübner, Niedersächsisches Landesmuseum Hannover

Fossil skull of the juvenile specimen of Dysalotosaurus lettowvorbecki. Credit: Tom Hübner, Niedersächsisches Landesmuseum Hannover

A new study conducted at the University of Bristol and published online today in the Journal of Evolutionary Biology sheds light on how the brain and inner ear developed in dinosaurs.

Stephan Lautenschlager from Bristol's School of Earth Sciences, together with Tom Hübner from the Niedersächsische Landesmuseum in Hannover, Germany, picked the brains of 150 million year old dinosaurs.

The two palaeontologists studied different fossils of the Jurassic dinosaur Dysalotosaurus lettowvorbecki: a very young (juvenile) individual of approximately three years of age and a fully grown specimen of more than 12 years of age.

Stephan Lautenschlager, lead author of the paper, said: "The two different growth stages of Dysalotosaurus provided a unique opportunity to study their brain, and how it developed during the growth of the animal."

Using high-resolution CT scanning and 3D computer imaging, it was possible to reconstruct and visualise the brain and inner ear of Dysalotosaurus lettowvorbecki – a small, plant-eating dinosaur, which lived 150 million years ago, in what is now Tanzania.

Co-author Tom Hübner said: "Well-preserved fossil material, which can be used to reconstruct the brain anatomy is usually rare. Thus, we were fortunate to have different growth stages available for our study."

Reconstruction of the brain in the young and fully grown Dysalotosaurus lettowvorbecki. Credit: Stephan Lautenschlager, University of Bristol

By looking at the brain and inner ear anatomy, the two researchers found that the brain of Dysalotosaurus underwent considerable changes during growth – most likely as a response to environmental and metabolic requirements. However, important parts responsible for the sense of hearing and cognitive processes were already well developed in the young individual.

Stephan Lautenschlager said: "Our study shows that the brain was already well-developed in the young dinosaurs and adapted perfectly to interact with their environment and other individuals."

This study has important ramifications for the understanding of how parts of the brain developed in dinosaurs. However, further research into that field is necessary to investigate if the pattern of brain development in individual dinosaurs is also reflected in a large scale trend during the more than 150 million years of dinosaur evolution.

The study by Stephan Lautenschlager (Bristol) and Tom Hübner (Hannover) is published today in the Journal of Evolutionary Biology.

More information: 'Ontogenetic trajectories in the ornithischian endocranium' by Stephan Lautenschlager and Tom Hübner in the Journal of Evolutionary Biology

Provided by University of Bristol

"Fossil brain teaser: New study reveals patterns of dinosaur brain development." May 20th, 2013. http://phys.org/news/2013-05-fossil-bra ... terns.html

 

[ramonmercado]

More refined table manners?

Allosaurus Fed More Like a Falcon Than a Crocodile: Engineering, Anatomy Work Reveals Differences in Dinosaur Feeding Styles
http://www.sciencedaily.com/releases/20 ... 152638.htm

A modern-day kestrel (a small falcon) is perched atop the skull of the Jurassic predatory dinosaur Allosaurus. A key finding of the new study is that Allosaurus had a feeding style similar to falcons. In both cases, tearing flesh from carcasses involved grasping meat with the jaws and tugging back and up with the neck and body. (Credit: WitmerLab, Ohio University)
May 21, 2013 — The mighty T. rex may have thrashed its massive head from side to side to dismember prey, but a new study shows that its smaller cousin Allosaurus was a more dexterous hunter and tugged at prey more like a modern-day falcon.

"Apparently one size doesn't fit all when it comes to dinosaur feeding styles," said Ohio University paleontologist Eric Snively, lead author of the new study published today in Palaeontologia Electronica. "Many people think of Allosaurus as a smaller and earlier version of T. rex, but our engineering analyses show that they were very different predators."

Snively led a diverse team of Ohio University researchers, including experts in mechanical engineering, computer visualization and dinosaur anatomy. They started with a high-resolution cast of the five-foot-long skull plus neck of the 150-million-year-old predatory theropod dinosaur Allosaurus, one of the best known dinosaurs. They CT-scanned the bones at O'Bleness Memorial Hospital in Athens, which produced digital data that the authors could manipulate in a computer.

Snively and mechanical engineer John Cotton applied a specialized engineering analysis borrowed from robotics called multibody dynamics. This allowed the scientists to run sophisticated simulations of the head and neck movements Allosaurus made when attacking prey, stripping flesh from a carcass or even just looking around.

"The engineering approach combines all the biological data—things like where the muscle forces attach and where the joints stop motion—into a single model. We can then simulate the physics and predict what Allosaurus was actually capable of doing," said Cotton, an assistant professor in the Russ College of Engineering and Technology.

To figure out how Allosaurus de-fleshed a Stegosaurus, the team had to "re-flesh" Allosaurus. The anatomical structure of modern-day dinosaur relatives, such as birds and crocodilians, combined with tell-tale clues on the dinosaur bones, allowed Snively and anatomists Lawrence Witmer and Ryan Ridgely to build in neck and jaw muscles, air sinuses, the windpipe and other soft tissues into their Allosaurus 3D computer model.

"Dinosaur bones simply aren't enough," said Witmer, Chang Professor of Paleontology in the Heritage College of Osteopathic Medicine and principal investigator on the National Science Foundation's Visible Interactive Dinosaur Project that provided funding for this research. "We need to know about the other tissues that bring the skeleton to life."

A key finding was an unusually placed neck muscle called longissimus capitis superficialis. In most predatory dinosaurs, such as T. rex, which Snively studied previously, this muscle passed from the side of the neck to a bony wing on the outer back corners of the skull.

"This neck muscle acts like a rider pulling on the reins of a horse's bridle," explained Snively. "If the muscle on one side contracts, it would turn the head in that direction, but if the muscles on both sides pull, it pulls the head straight back."

But the analysis of Allosaurus revealed that the longissimus muscle attached much lower on the skull, which, according to the engineering analyses, would have caused "head ventroflexion followed by retraction."

"Allosaurus was uniquely equipped to drive its head down into prey, hold it there, and then pull the head straight up and back with the neck and body, tearing flesh from the carcass … kind of like how a power shovel or backhoe rips into the ground," Snively said.

In the animal world, this same de-fleshing technique is used by small falcons, such as kestrels. Tyrannosaurs like T. rex, on the other hand, were engineered to use a grab-and-shake technique to tear off hunks of flesh, more like a crocodile.

But the team's engineering analyses revealed a cost to T. rex's feeding style: high rotational inertia. That large bony and toothy skull perched at the end of the neck made it hard for T. rex to speed up or slow down its head or to change its course as it swung its head around.

Allosaurus, however, had a relatively very light head, which the team discovered as they restored the soft tissues and air sinuses.

Having a lot of mass sitting far away from the axis of head turning, as in T. rex, increases rotational inertia, whereas having a lighter head, as in Allosaurus, decreases rotational inertia, the researchers explained. An ice skater spins faster and faster as she tucks her arms and legs into her body, decreasing her rotational inertia as the mass of her limbs moves closer to the axis of spinning.

"Allosaurus, with its lighter head and neck, was like a skater who starts spinning with her arms tucked in," said Snively, "whereas T. rex, with its massive head and neck and heavy teeth out front, was more like the skater with her arms fully extended … and holding bowling balls in her hands. She and the T. rex need a lot more muscle force to get going."

The end result is that Allosaurus was a much more flexible hunter that could move its head and neck around relatively rapidly and with considerable control. That control, however, came at the cost of brute-force power, requiring a de-fleshing style that, like a falcon, recruited the whole neck and body to strip flesh from the bones.

The Ohio University team will continue to use their engineering approach to explore additional differences in dinosaur feeding styles.

Story Source:

The above story is reprinted from materials provided by Ohio University.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

Journal Reference:

Eric Snively, John R. Cotton, Ryan Ridgely, and Lawrence M. Witmer. Multibody dynamics model of head and neck function in Allosaurus (Dinosauria, Theropoda). Palaeontologia Electronica, 2013 (in press)

 

[ramonmercado]

How 'Parrot Dinosaur' Switched from Four Feet to Two as It Grew
http://www.sciencedaily.com/releases/20 ... 092147.htm

A Psittacosaurus skeleton cast in the permanent collection of The Children’s Museum of Indianapolis. (Credit: Photo by Michelle Pemberton, via Wikimedia Commons (Creative Commons license))

June 28, 2013 — Tracking the growth of dinosaurs and how they changed as they grew is difficult. Using a combination of biomechanical analysis and bone histology, palaeontologists from Beijing, Bristol, and Bonn have shown how one of the best-known dinosaurs switched from four feet to two as it grew.

Psittacosaurus, the 'parrot dinosaur' is known from more than 1000 specimens from the Cretaceous, 100 million years ago, of China and other parts of east Asia. As part of his PhD thesis at the University of Bristol, Qi Zhao, now on the staff of the Institute for Vertebrate Paleontology in Beijing, carried out the intricate study on bones of babies, juveniles and adults.

Dr Zhao said: "Some of the bones from baby Psittacosaurus were only a few millimetres across, so I had to handle them extremely carefully to be able to make useful bone sections. I also had to be sure to cause as little damage to these valuable specimens as possible."

With special permission from the Beijing Institute, Zhao sectioned two arm and two leg bones from 16 individual dinosaurs, ranging in age from less than one year to 10 years old, or fully-grown. He did the intricate sectioning work in a special palaeohistology laboratory in Bonn, Germany,

The one-year-olds had long arms and short legs, and scuttled about on all fours soon after hatching. The bone sections showed that the arm bones were growing fastest when the animals were ages one to three years. Then, from four to six years, arm growth slowed down, and the leg bones showed a massive growth spurt, meaning they ended up twice as long as the arms, necessary for an animal that stood up on its hind legs as an adult.

Professor Xing Xu of the Beijing Institute, one of Dr Zhao's thesis supervisors, said: "This remarkable study, the first of its kind, shows how much information is locked in the bones of dinosaurs. We are delighted the study worked so well, and see many ways to use the new methods to understand even more about the astonishing lives of the dinosaurs."

Professor Mike Benton of the University of Bristol, Dr Zhao's other PhD supervisor, said: "These kinds of studies can also throw light on the evolution of a dinosaur like Psittacosaurus. Having four-legged babies and juveniles suggests that at some time in their ancestry, both juveniles and adults were also four-legged, and Psittacosaurus and dinosaurs in general became secondarily bipedal."

The paper is published in Nature Communications.

Story Source:

The above story is reprinted from materials provided by University of Bristol.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

Journal Reference:

Qi Zhao, Michael J. Benton, Corwin Sullivan, P. Martin Sander, Xing Xu. Histology and postural change during the growth of the ceratopsian dinosaur Psittacosaurus lujiatunensis. Nature Communications, 2013; 4 DOI: 10.1038/ncomms3079

 

[ramonmercado]

Dinosaurs, Diets and Ecological Niches: Study Shows Recipe for Success
http://www.sciencedaily.com/releases/20 ... 183640.htm

Dr. Jordan Mallon in the museum’s fossil collections with three of the skulls he examined for his study on niche partitioning. Front to back: Lambeosaurus clavinitelis (a hadrosaur), Chasmosaurus belli, and Styracosaurus albertensis, both ceratopsids (horn-faced dinosaurs). (Credit: Dan Smythe © Canadian Museum of Nature)

July 10, 2013 — A new study by a Canadian Museum of Nature scientist helps answer a long-standing question in palaeontology -- how numerous species of large, plant-eating dinosaurs could co-exist successfully over geological time.

Dr. Jordan Mallon, a post-doctoral fellow at the museum, tackled the question by measuring and analyzing characteristics of nearly 100 dinosaur skulls recovered from the Dinosaur Park Formation in Alberta, Canada. The specimens now reside in major fossil collections across the world, including the collections of the Canadian Museum of Nature. The work was undertaken as part of his doctoral thesis at the University of Calgary under the supervision of Dr. Jason Anderson.

Mallon's results, published in the July 10, 2013 issue of the open-access journal PLOS ONE, indicate that these megaherbivores (all weighing greater than 1,000 kg) had differing skull characteristics that would have allowed them to specialize in eating different types of vegetation. The results support a concept known as niche partitioning, which dates to the 19th-century studies of Charles Darwin and came into its own in the 1950s with the development of the science of ecology.

The Dinosaur Park Formation is between 76.5 and 75 million years old and is known for its rich concentration of dinosaur remains. The rock unit has yielded nearly 20 species of megaherbivores from the Late Cretaceous period. Of these, six species would have coexisted at any one time, including two types of ankylosaurs (tank-like armoured dinosaurs), two types of hadrosaurs (duck-billed dinosaurs), and two types of ceratopsids (horn-faced dinosaurs).

Dr. Jordan Mallon in the museum's fossil collections with three of the skulls he examined for his study on niche partitioning. Front to back: Lambeosaurus clavinitelis (a hadrosaur), Chasmosaurus belli, and Styracosaurus albertensis, both ceratopsids (horn-faced dinosaurs).

Modern megaherbivores include elephants, giraffes, hippos and rhinos. "Today's megaherbivore communities are not nearly as diverse as those from the Late Cretaceous of Alberta, and most other fossil communities also pale by comparison. So the question is: how does an environment support so many of these large herbivores at once?" asks Mallon.

Mallon tested two competing hypotheses. The first is that availability of food was not a limiting factor in species survival. Plants may have been either super-abundant, so the megaherbivores did not have to compete for food, or the dinosaurs' metabolisms were relatively low, so the environment could support more species relative to a fauna comprised entirely of high-metabolic animals.

The second hypothesis is that the available food resources were limiting and that niche partitioning came into play; in other words, there weren't that many plants to go around so that the species had to share available food sources by specializing on different types of vegetation.

"If niche partitioning was in effect, then you would expect to see various dietary adaptations among the coexisting dinosaur species, " explains Mallon. "So you would look for differences in the shapes of the skull, in the teeth, and in the beaks that might reflect adaptations for feeding on diverse plants or plant parts. " These differences, for example, would reflect whether a dinosaur was adapted to feeding on soft or hard plant tissues.

Until Mallon's study, neither of these hypotheses had been rigorously tested with such a large sample size. For each of the nearly 100 dinosaur skulls he studied, Mallon measured 12 characteristics that are known to relate to diet in modern animals. These include depth of the jaw, angle of the beak, size of muscle insertions, and length of the tooth row. "We can apply those same functional and mechanical principles to dinosaurs to see what they might tell us about niche partitioning," he explains.

Styracosaurus albertensis, a ceratopsid (horn-faced dinosaur), was one of the many skulls studied by Dr. Jordan Mallon for his study on niche partitioning. This specimen is in the museum's collections in Gatineau, Quebec.

Not unexpectedly, differences were found between the three major groups (ankylosaurs, hadrosaurs and ceratopsids). But more striking were the subtle yet significant differences within each of the three groups that were probably related to feeding. "We found those differences that were previously suspected but never demonstrated, " explains Mallon.

As an example, the palaeontologist suggests that ankylosaurs probably specialized on eating ferns, because they stood low to the ground, and their wide beaks would have allowed them to feed efficiently on abundant, relatively low-nutrient plants. However, within this group, the family known as nodosaurids (clubless ankylosaurs) had more efficient jaw mechanics that might have enabled them to include tougher plants in their diets. In contrast, ceratopsids had skulls that suggest they were adapted to feeding on mid-sized shrubs, while the taller hadrosaurs were less picky and would have fed on anything within reach.

Although different species came and went, the same ecological roles were filled over the 1.5 million year span of the Dinosaur Park Formation. "This tells us that niche partitioning was a viable strategy for the coexistence of these animals," adds Mallon. "The study provides further evidence to explain why dinosaurs were one of the most successful groups of animals to live on this planet."

The study was funded by an NSERC Alexander Graham Bell Canada Graduate Scholarship, Alberta Innovates Technology Futures graduate student scholarship, Queen Elizabeth II scholarship, and a research grant from the Jurassic Foundation. The dinosaur specimens examined reside in the collections of the Canadian Museum of Nature (Ottawa), Royal Ontario Museum (Toronto), Royal Tyrrell Museum of Palaeontology (Drumheller, Alberta), University of Alberta (Edmonton), American Museum of Natural History (New York), Field Museum (Chicago), Yale Peabody Museum (New Haven, Connecticut), National Museum of Natural History (Washington), and Natural History Museum (London).

Story Source:

The above story is reprinted from materials provided by Canadian Museum of Nature.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

Journal Reference:

Jordan C. Mallon, Jason S. Anderson. Skull Ecomorphology of Megaherbivorous Dinosaurs from the Dinosaur Park Formation (Upper Campanian) of Alberta, Canada. PLoS ONE, 2013; 8 (7): e67182 DOI: 10.1371/journal.pone.0067182

 

[ramonmercado]

Nasutoceratops: 'Big-nose, horn-face' dinosaur described
http://www.bbc.co.uk/news/science-environment-23329193
By Rebecca Morelle
Science reporter, BBC World Service

Artist's impression of Nasutoceratops titusi

The dinosaur roamed the Earth about 75 million years ago, during the Late Cretaceous period

An unusual new species of dinosaur, unearthed from the deserts of Utah, has been described by scientists.

The 5m-long (15ft) beast is a member of the triceratops family, but with a huge nose and exceptionally long horns, palaeontologists say it is unlike anything they have seen before.

It has been named accordingly as Nasutoceratops titusi, which means big-nose, horn-face.

The research is published in the Proceedings of the Royal Society B.

Dr Mark Loewen, from the University of Utah and Natural History Museum of Utah, told BBC News: "This dinosaur just completely blew us away.

"We would never have predicted it would look like this - it is just so outside of the norm for this group of dinosaurs."

Fearsome vegetarian?

The creature was first discovered in 2006 the Grand Staircase-Escalante Monument area of Utah.

Continue reading the main story
“
Start Quote

The horns are by far the absolute largest of any member of its group of dinosaurs”

Dr Mark Loewen
University of Utah
However, it has taken several years to prepare and then study the fossil in detail.

The rocks it was found in date to about 75-million-years old, so the beast would have roamed the Earth during the Late Cretaceous period.

"The horns are by far the absolute largest of any member of its group of dinosaurs - they curve sideways and forwards," explained Dr Loewen.

"In addition it has the biggest nose of its group too."

He added that it also had a scalloped frill at the back of its head.

Nasutoceratops was also hefty, weighing about 2.5 tonnes, and with its unusual looks it would have cut a fearsome figure.

However this species, like all members of the triceratops family is a herbivore. It would have been more concerned with feasting on plants in its tropical, swampy surrounds than terrorising other dinosaurs.

'Treasure trove'

Skull of Nasutoceratops (Rob Gaston)
The dinosaur has a big nose and sports two large horns above its eyes
Nasutoceratops is one of a number of species that have been discovered in this area of North America.

The desert where it was found would have once formed part of a continent called Laramidia, which has been described as a treasure trove for fossils.

Other plant-eating species, including two other kinds of horned dinosaurs and duck-billed hadrosaurs, were found close to Nasutoceratops titusi, suggesting that the creatures were able to co-exist.

Dr Loewen said: "All of these animals are upwards of three tonnes... You have an environment where you have all of these large herbivores competing for food.

"We aren't really sure how you can support all of these animals, but you do find them all in the rock at the same time."

He added that other unusual new species were also emerging from the site.

 

[ramonmercado]

Plant-eating dinosaurs replaced teeth often, carried spares
July 17th, 2013 in Other Sciences / Archaeology & Fossils

Some of the largest herbivorous dinosaurs replaced their teeth at a rate of approximately one tooth every 1-2 months to compensate for tooth wear from crunching up plants, according to research published July 17 in the open access journal PLOS ONE by Michael D'Emic from Stony Brook University and colleagues from other institutions.

A little like counting tree rings, researchers can estimate rates of tooth formation and replacement in extinct animals by counting lines of deposition of tooth dentin, a layer below enamel that grows throughout an animal's life. In this study, authors estimated tooth replacement rates in Diplodocus and Camarasaurus, two distantly related, different-looking sauropod dinosaurs of similar giant size. Camarasaurus had up to three "baby teeth" lined up in each tooth socket, and replaced about one tooth every 62 days. Each Diplodocus tooth socket held up to five replacement teeth and one functional tooth, and each tooth was replaced once in 35 days.

This is a CT-generated movie of the premaxilla of Diplodocus (YPM 4677), with bone rendered transparent and teeth opaque. Credit: D'Emic MD, Whitlock JA, Smith KM, Fisher DC, Wilson JA (2013) Evolution of High Tooth Replacement Rates in Sauropod Dinosaurs. PLoS ONE 8(7): e69235. doi:10.1371/journal.pone.0069235

As D'Emic explains, "A nearly 100-foot-long sauropod would have had a fresh tooth in each position about every one to two months, sometimes less. Effectively, sauropods took a 'quantity over quality' approach to making teeth, opposite the approach taken by large animals —mammals—today."

These sauropod dinosaurs were the largest terrestrial herbivores known, and would have required huge food supplies. Eating large amounts of plant foods likely caused extensive tooth wear, requiring this constant growth and replacement. Differences in the rates at which these species replaced their teeth could reflect differences in their feeding strategies or food choices.

More information: PLoS ONE 8(7):e69235.
doi:10.1371/journal.pone.0069235

Provided by Public Library of Science

"Plant-eating dinosaurs replaced teeth often, carried spares." July 17th, 2013. http://phys.org/news/2013-07-plant-eati ... teeth.html

 

[ramonmercado]

New Evidence for Warm-Blooded Dinosaurs
http://www.sciencedaily.com/releases/20 ... 194948.htm

T. rex (artist's rendering). (Credit: © DX / Fotolia)

July 17, 2013 — University of Adelaide research has shown new evidence that dinosaurs were warm-blooded like birds and mammals, not cold-blooded like reptiles as commonly believed.

In a paper published in PLoS ONE, Professor Roger Seymour of the University's School of Earth and Environmental Sciences, argues that cold-blooded dinosaurs would not have had the required muscular power to prey on other animals and dominate over mammals as they did throughout the Mesozoic period.

"Much can be learned about dinosaurs from fossils but the question of whether dinosaurs were warm-blooded or cold-blooded is still hotly debated among scientists," says Professor Seymour.

"Some point out that a large saltwater crocodile can achieve a body temperature above 30°C by basking in the sun, and it can maintain the high temperature overnight simply by being large and slow to change temperature.

"They say that large, cold-blooded dinosaurs could have done the same and enjoyed a warm body temperature without the need to generate the heat in their own cells through burning food energy like warm-blooded animals."

In his paper, Professor Seymour asks how much muscular power could be produced by a crocodile-like dinosaur compared to a mammal-like dinosaur of the same size.

Saltwater crocodiles reach over a tonne in weight and, being about 50% muscle, have a reputation for being extremely powerful animals.

But drawing from blood and muscle lactate measurements collected by his collaborators at Monash University, University of California and Wildlife Management International in the Northern Territory, Professor Seymour shows that a 200 kg crocodile can produce only about 14% of the muscular power of a mammal at peak exercise, and this fraction seems to decrease at larger body sizes.

"The results further show that cold-blooded crocodiles lack not only the absolute power for exercise, but also the endurance, that are evident in warm-blooded mammals," says Professor Seymour.

"So, despite the impression that saltwater crocodiles are extremely powerful animals, a crocodile-like dinosaur could not compete well against a mammal-like dinosaur of the same size.

"Dinosaurs dominated over mammals in terrestrial ecosystems throughout the Mesozoic. To do that they must have had more muscular power and greater endurance than a crocodile-like physiology would have allowed."

His latest evidence adds to that of earlier work he did on blood flow to leg bones which concluded that the dinosaurs were possibly even more active than mammals.

Story Source:

The above story is reprinted from materials provided by University of Adelaide.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

Journal Reference:

Roger S. Seymour. Maximal Aerobic and Anaerobic Power Generation in Large Crocodiles versus Mammals: Implications for Dinosaur Gigantothermy. PLoS ONE, 2013; 8 (7): e69361 DOI: 10.1371/journal.pone.0069361

 

[ramonmercado]

Rare Fossil of Late Cretaceous Plesiosaur Discovered
http://www.sciencedaily.com/releases/20 ... 161916.htm

An artist rendering of an elasmosaur, created by University of Alabama undergraduate student Asher Albein. (Credit: University of Alabama)

July 16, 2013 — University of Alabama researchers have discovered the fossilized remains of a large marine reptile that once ruled the open seas 80 million years ago.

The initial discovery, made June 20 by middle-school student Noah Traylor during a UA-hosted expedition, was later identified as part of a large neck vertebra of an elasmosaur, which is a subgroup of the late Cretaceous plesiosaurs.

Elasmosaurid plesiosaurs are easily recognized by their large body size -- some species reach up to 45 feet in length.

"Think Loch Ness monster," said Dr. Dana Ehret, UA Museum paleontologist. "They have very large flippers for swimming and extremely long necks, consisting of up to about 70 neck vertebrae."

Plesiosaurs became extinct by the end of Cretaceous, or about 65.5 million years ago, and they are generally rare in the fossil record for Alabama. This is only the second elasmosaurid specimen containing more than one or two bones found in the state, Ehret said. The first, which consists of 22 vertebrae, was found in the late 1960s and is now part of UA Collections.

This discovery appears to be on par with the first one. To date, about 15 large vertebrae, a few paddle bones and many bone fragments have been collected, but an extensive excavation is still in progress, so Ehret is uncertain how complete this skeleton is.

"We find a lot of the more common fossils here, but this is a macropredator that is not normally found in Alabama," Ehret said. "It's really interesting because it gives us a bigger picture of what was happening in Alabama at that time."

The skeleton was also not found near water. Ehret said during the late Cretaceous period, temperatures were much warmer than they are today, resulting in higher sea levels. The specimen was found in a small quarry in rural Greene County, a region commonly called the "Black Belt."

The "Black Belt" represents the late Cretaceous shoreline in the Gulf Coast. The sediments found in this region are classified as chalk, are composed of extinct microscopic organisms and are extremely nutrient rich, making them the perfect place for farming.

The discovery was made during the Museum's Expedition 35, which was hosted by UA's Alabama Museum of Natural History and led by Randy Mecredy, director of the Museum. The expedition is an annual summer program that is open to middle and high-school students.

In addition to Ehret, others involved in the excavation include students from the expedition, Dr. Takehito "Ike" Ikejiri with UA's department of geological sciences, museum staff, Dr. Prescott Atkinson of the University of Alabama at Birmingham, the UA Museum's Board of Regents and a few UA geology students.

The bones were initially excavated in place from the chalk in the quarry. Once they were able to determine the size and extent of the individual bones, those working the excavation could take them out of the ground and transport them back to the museum. Some pieces came back loose, while others were wrapped to prevent them from falling apart.

In the paleontology lab, the bones are now being unwrapped and prepared. Specimens are washed and scrubbed to remove loose sediments, and, for those that are still embedded in the chalk sediment, Ehret said they will use different tools to remove the sediment.

It will take several weeks to prepare the bones properly and then harden them to ensure they will not later fall apart. Once finished, the specimen will be displayed in UA's Smith Hall.

"From a research standpoint, this is an important find. To have this many pieces, you can do an extensive comparative analysis," Mecredy said. "But, it's also having the ability to take high-school and middle-school students in the field where they find these things. It inspires them to pursue science-related fields."

Story Source:

The above story is reprinted from materials provided by University of Alabama.

 

[ramonmercado]

Paleontologists discover dinosaur tail in northern Mexico
http://www.newsdaily.com/article/7e8b46 ... ern-mexico
TUESDAY JUL 23, 2013 | LUC COHEN FOR REUTERS

A fossilized tail of a duck-billed dinosaur, or hadrosaur, is seen in the Municipality of General Cepeda, Coahuila
Credit: Handout/Reuters

MEXICO CITY (Reuters) - A team of paleontologists have discovered the fossilized remains of a 72 million-year-old dinosaur tail in a desert in northern Mexico, the country's National Institute for Anthropology and History (INAH) said on Monday.

Apart from being unusually well preserved, the 5 meter (16 foot) tail was the first ever found in Mexico, said Francisco Aguilar, INAH's director in the border state of Coahuila.

The team, made up of paleontologists and students from INAH and the National Autonomous University of Mexico (UNAM), identified the fossil as a hadrosaur, or duck-billed dinosaur.

The tail, found near the small town of General Cepeda, likely made up half the dinosaur's length, Aguilar said.

Paleontologists found the 50 vertebrae of the tail completely intact after spending 20 days in the desert slowly lifting a sedimentary rock covering the creature's bones.

Strewn around the tail were other fossilized bones, including one of the dinosaur's hips, INAH said.

Dinosaur tail finds are relatively rare, according to INAH. The new discovery could further understanding of the hadrosaur family and aid research on diseases that afflicted dinosaur bones, which resembled those of humans, Aguilar said.

Scientists have already determined that dinosaurs suffered from tumors and arthritis, for example.

Dinosaur remains have been found in many parts of the state of Coahuila, in addition to Mexico's other northern desert states.

"We have a very rich history of paleontology," Aguilar said.

He noted that during the Cretaceous period, which ended about 65 million years ago, much of what is now central northern Mexico was on the coast. This has enabled researchers to unearth remains of both marine and land-based dinosaurs.

The presence of the remains was reported to INAH by locals in June 2012. After initial inspections, excavation began earlier this month. The remains of the tail will be transferred to General Cepeda for cleaning and further investigation.

(This version of story corrects to show researchers were paleontologists, not archaelogists)

(Editing by Dave Graham and Philip Barbara)

Copyright (2013) Thomson Reuters. Click for restrictions

This article was distributed through the NewsCred Smartwire. Original article © Reuters 2013

 

[ramonmercado]

Feathered dinosaurs had 'flight-ready' brains
http://www.bbc.co.uk/news/science-environment-23514985
By Melissa Hogenboom
Science reporter, BBC News

Archaeopteryx artwork

Archaeopteryx is no longer regarded as the only missing link for the transition from dinosaur to bird

Several ancient dinosaurs evolved the brainpower needed for flight long before they could take to the skies, scientists say.

Non-avian dinosaurs were found to have "bird brains", larger than that of Archaeopteryx, a 150 million-year-old bird-like dinosaur.

Once regarded as a unique transition between dinosaurs and birds, scientists say Archaeopteryx has now lost its pivotal place.

The study is published in Nature.

A recent discovery in China which unveiled the earliest creature yet discovered on the evolutionary line to birds, also placed Archaeopteryx in less of a transitional evolutionary place.

Bird brains tend to be more enlarged compared to their body size than reptiles, vital for providing the vision and coordination needed for flight.

Scientists using high-resolution CT scans have now found that these "hyper-inflated" brains were present in many ancient dinosaurs, and had the neurological hardwiring needed to take to the skies.

This included several bird-like oviraptorosaurs and the troodontids Zanabazar junior, which had larger brains relative to body size than that of Archaeopteryx.

This latest work adds to previous studies which found the presence of feathers and wishbones on ancient dinosaurs.

A 3D rendering from CT scans of the troodontid dinosaur Zanabazar junior In this image the endocast (brain) is rendered opaque and the skull transparent
Dinosaurs like the troodontid Zanabazar junior had enlarged "bird brains"
"Archaeopteryx has always been set up as a uniquely transitional species between feathered dinosaurs and modern birds," said lead author Amy Balanoff, of the American Museum of Natural History and Stony Brook University.

By studying the brains of closely related dinosaurs, she said that Archaeopteryx "might not have been so special".

"Large forebrains are typically correlated with things like increased cognition and parental care of the young, while not flying, they were definitely doing other things with these enlarged brains.

"A lot of these characteristics that are distinctive within birds evolved much earlier in the history of Theropods . It's interesting that the brain followed this pattern as well. The large brain evolved before flight earlier than was previously thought," Dr Balanoff told BBC News.

Continue reading the main story
Other ancient birds
Epidexipteryx
Epidexipteryx - a very small feathered dinosaur discovered in China and first reported in 2008 (above). It had four long tail feathers but there is little evidence that it could fly.

Jeholornis - this creature lived 120 million years ago in the Cretaceous. It was a relatively large bird, about the size of a turkey. First discovered in China, and reported in 2002.

Sapeornis - lived 110 to 120 million years ago. Another small primitive bird about 33 centimetres in length. It was discovered in China and was first reported in 2002.

Xiaotingia, a chicken-sized dinosaur which dates back 155 million years to the Jurassic Period, reported in 2011.

Aurornis, which means "dawn bird" lived about 160 million years ago, about 50cm tail to beak reported in China in 2013.

By compiling CT scans, the scientists created 3D reconstructions of dinosaur skulls as well as modern bird brains. They also calculated the total volume of each digital brain and determined the size of major anatomical regions such as the olfactory bulbs, cerebrum, optic lobes and cerebellum.

"The story of brain size is more than its relationship to body size," said co-author Gabriel Bever, of the New York Institute of Technology.

"If we also consider how the different regions of the brain changed relative to each other, we can gain insight into what factors drove brain evolution as well as what developmental mechanisms facilitated those changes."

Adrian Thomas at the department of zoology at Oxford University, who was not involved with the study, said the picture now is much more complicated than "dinosaurs couldn't fly and Archaeopteryx could".

"There were a whole group of more or less distantly related feathered dinosaurs, some were gliding down from trees, some were flapping, and it all seemed to be happening at the same time.

"Rather than a straight [evolutionary] path that led Archaeopteryx to birds, the picture now is that there were lots of dinosaurs exploiting the advantages of gliding and flight. The birds are the ones that carried on successfully to the present day," Prof Thomas told BBC News.

But he added that the "processing power required for flight is relatively simple" compared to walking and running.

"So it is interesting, but not a great surprise, to see increased brain size in these dinosaurs associated with their highly agile lifestyles."

 

[ramonmercado]

Ostrich necks give clues to dinosaur flexibility
By Melissa Hogenboom
http://www.bbc.co.uk/news/science-environment-23679932
Science reporter, BBC News

Artwork of four Brachiosaurus dinosaurs feeding in a forest of tree ferns next to snow-capped mountains

A thick mass of neck muscle restricted the range over which the dinosaurs could reach

The familiar view of sauropod dinosaurs reaching out for vegetation using their long, graceful necks may not be entirely accurate, say scientists.

A study of modern-day ostriches suggests the ancient animals were probably quite stiff in their movement.

Sauropod dinosaurs had a thick mass of muscle in their necks and the researchers say this would probably have restricted the range over which the beasts could move their heads.

The study is published in Plos One.

Its authors say the findings have implications for the way we display the dinosaurs in museum exhibits and in the media.

Computer modelling that has been used to simulate sauropod movements will not have portrayed the lack of neck flexibility accurately, the team adds.

For example, the BBC's landmark TV series Walking with Dinosaurs modelled the neck movement using the position of the vertebrae.

But this did not account for the effects of soft tissues like muscle and cartilage, which this new study tries to incorporate by looking at ostriches.

The team, led by Matthew Cobley from the University of Utah, US, has shown that muscle mass reduces the maximum flexibility of ostrich necks.

The researchers measured the flexibility of the flightless birds with all their muscle tissue intact, and then slowly removed the muscles to test how this changed the situation.

As they are the largest birds to exhibit elongated necks, with vertebrae and musculature broadly comparable to those of sauropods, ostriches provide useful insights into the past.

"Previous studies looked at the skeleton on its own and the assumption was that flexibility is limited by the bones of the skeleton, but our study shows it's actually the soft tissue around it," said Mr Cobley.

He added that computer modelling of any biological system needed to be "ground-truthed" before it was accepted by the scientific community and presented to the public.

Ostrich
The long-necked ostrich gives scientists clues about its sauropod relative
"It's easy to be swayed by these beautifully reconstructed models of dinosaurs, but if these models aren't based on real, empirical data taken from living animals we can actually study, they only serve to confuse the general public."

The amount of cartilage in the neck and varying distances between vertebral joints could also have caused reduced flexibility, the research found.

A common sauropod picture in films and museums is a creature reaching from high tree-tops to food that's very low on the ground, but this new work could now change how the animals are depicted.

It suggest the lack of flexibility may have restricted the range of food to which the the dinosaurs had access. And they may have had to work harder for their food - the hefty herbivores needed about 400kg of plant-based material each day.

"Different sauropods were limited to different food types. It's why you don't see giraffes eating from bushes from the floor or goats eating from the tree-tops," Mr Cobley told BBC News.

"There was a better division of resources between dinosaurs, with the taller ones limited to taller trees and smaller ones to grazing bushes on the floor."

Michael Benton of Bristol University, UK, commenting on the research, said the study "provides food for thought" and a warning about reconstructing sauropod necks without considering the distribution of soft tissues.

"Formerly, people assumed a standard amount of soft tissue that would limit flexibility, but it is rather more complex, and some previous reconstructions of sauropod necks snaking around must be modified," Prof Benton told BBC News.

 

[rynner2]

Science 'could lose' duelling dinos
By Simon Redfern, Science reporter, BBC News

Rare dinosaur remains could be forever lost to the scientific community when they go under the hammer in November.
The remarkably preserved fossils of two "duelling" dinosaurs frozen in a death clinch could fetch up to $10m.
But scientists want the opportunity to examine the specimens of the tyrannosaur, which appears to have bitten off more than it could chew.
Details of the discovery, from Montana, US, were discussed at the British Science Festival in Newcastle.

The large arms and thin head of this most complete tyrannosaur ever discovered suggest it is a new species, called Nanotyrannus, living alongside and related to T. rex.
The observations were made by Dr Phil Manning of Manchester University.

Some 65 to 67 million years ago, in an area that now lies the middle of Montana, T. rex was the top predator of the ecosystem. Dr Manning has just returned from an excavation of a new T. rex skeleton that he is preparing for a museum in Leiden, Germany.

Fossil fragments of T. rex are found throughout the rocks called the "Hell Creek Formation" in Montana, but never before has an entire tyrannosaur skeleton been found.

Only two T. rex skeletons that are more than half complete have been ever been recovered. The Fields Museum in Chicago has the most complete T. rex, at 85% of a skeleton, which was bought at auction for a record sum, and the Black Hills Museum in South Dakota has a 65% complete T. rex.

There has been great excitement, therefore, over the recent excavation of an entire and complete tyrannosaur predator from the Hell Creek Formation. More than that, it was found forever frozen in a linked death clasp with its prey, a complete Triceratops.

Dr Phil Manning from the University of Manchester explained at the British Science Festival in Newcastle how new observations show a tooth from the tyrannosaur embedded between the neck vertebrae of the Triceratops, while the skull of the tyrannosaur appears to have been shattered by a blow from the Triceratops.

"It was a bad day for both of them" quipped Dr Manning. "These animals could have been fighting on the banks of a river. They both became mortally injured." They were then rapidly buried and preserved as fossils.

But there is more to this remarkable death duelling pair than the preservation of their last moments as entire skeletons. The preservation also solves a longstanding scientific question.

In 1988, a similar skull bone from a predatory dinosaur was identified as a distinct species, which was then named Nanotyrannus, but the identification from one skull fossil was not widely accepted, with many suggesting that this was simply a young T. rex.
The dispute over whether a second large predator lived alongside T. Rex has rumbled on over the last decades, but Dr Manning's observations of the new entire skeleton help resolve the issue.

T. rex has some notable distinctive features, one of which is its very small arms. Dr Phil Manning has just returned from a visit to inspect the new specimen from Montana, and described its very large fore arms. Despite being about half the body size of an adult T. rex the arms of Nanotyrannus are noticeably larger than those of T. rex.

Nanotyrannus is characterised by Dr Manning as having its own ecological niche, with a long swan-like neck, relatively large fore arms, and a narrower gracile skull. "If you think of the savannah of Africa today, the lion is taking down the big prey and the cheetah is maybe taking down the small prey. Maybe we are looking at the cheetah of the Cretaceous here: we've got similar niche partitioning of the ecosystem that existed 65 to 67 million years ago".

"When you have a big predator, like T. rex, it means that you have a healthy established ecosystem. So it's not surprising to find a more complex system in place at the end of the Cretaceous" Dr Manning explained.

Dr David Norman of the University of Cambridge was not involved in the study. He commented to the BBC "A really nice skull has been described previously, and looks rather low and long compared to a classic T. rex skull, which led to the suggestion of Nanotyrannus.
"If this new specimen has larger forelimbs and a gracile skull on a more slender swan-like neck, it provides plausible reasons to substantiate the idea that this is a new genus."

The remarkable specimen was discovered on private land by an independent fossil collector, and is now being offered for sale by auction. It is expected to fetch as much as $10m dollars when it goes under the hammer in November.

The scientific community demands that original research material like this sample be deposited in accessible museum collections if the description or discoveries of new species or genus are to be accepted, to allow observations to be verified and studied openly by others.

The auction of the Nanotyrannus - Triceratops pair may yet stymie the acceptance of Nanotyrannus as a new species. If it goes to a private collection it will no longer be available to science, and the unique observations made thus far will never be subject to peer-scrutiny.

The whole issue of the commercialisation of fossil discovery is raising concerns among palaeontologists and other scientists, and may hinder future discovery, they say.
Discussing the issue, Dr Norman commented: "This is the most distasteful part of it. Ever since the T. rex was sold to the Fields Museum in Chicago for $8m, the commercial value of fossils has been hyped.
"This spiralling effect means that more and more scientifically important objects risk being removed from the community for scientific study. They fall into private hands because they become objects d'art.

"It destroys the whole ethos of the availability of specimens. These fossils were left by Nature, shouldn't they be available to be appreciated and studied by everybody, rather than falling into private hands?
"There are national issues about how fossils are sold and valued that vary from country to country. It is becoming a minefield now that fossils can have a high value, and makes it a curatorial nightmare for museums."

http://www.bbc.co.uk/news/science-environment-24033966

 

[ramonmercado]

Dinosaur in a wind tunnel tests feathered flight
http://www.newscientist.com/article/dn2 ... jsMJcZ6ZvI
10:00 18 September 2013 by Alyssa Botelho

Video: Microraptor in wind tunnel reveals flight secrets

A life-sized model of a dinosaur has been suspended in a wind tunnel to help test how feathered dinosaurs might have taken to the air roughly 125 million years ago.

The results suggest that the small, four-winged creatures of the genus Microraptor would have been efficient gliders even without feathers. This supports the idea that plumage might not have evolved for flight but may instead have been a key aspect of sexual-selection displays.

The creatures lived during the early Cretaceous period and are a genus of dromaeosaurs – two-legged predatory dinosaurs that are related to birds. The first microraptor with preserved feathers was unearthed in China in 2003, showing long plumes on all four of its limbs. This set off a firestorm of debate about how the animal might have moved through the air, since this could offer clues to how bird ancestors first put their limbs to the task of gliding and flapping.

Model flyer

One of the fiercest points of contention was microraptors' leg positioning: were the legs splayed parallel to the forearms to form two pairs of wings, like a biplane? Or were they folded beneath its body, like the legs of modern raptors catching prey?

"For years scientists thought microraptors could fly but weren't sure how," says Gareth Dyke at the University of Southampton in the UK. For their tests, Dyke and his colleagues fashioned the first full-scale, anatomically accurate model of a microraptor from balsa wood, aluminium and mallard feathers. The model, dubbed Maurice, weighs in at about half a kilogram and has a 60-centimetre wingspan.

Maurice was suspended in a wind tunnel by piston-tipped poles, which allowed the team to alter the legs and tail mid-flight (see video, above). The model was then exposed to gusts of up to 20 metres per second. Airflow analysis suggests that the dinosaur probably could have switched between its possible leg configurations mid-air, and that either one would have allowed it to glide in roughly the same way.

Squirrely dino

Overall, microraptors would have been most stable in a slow glide that is less aerodynamically efficient but would have resulted in minimal height loss and longer flight distances. That kind of movement would have been ideal for an animal that combined arboreal and ground-based foraging by scampering up trunks and gliding between trees, like a modern-day flying squirrel, says Dyke.

What's more, Maurice's flight capabilities did not change when his feathers were removed. "The most important thing for this dinosaur was maximising wing surface rather than the presence of feathers," says Dyke.

"That's a key thing, because for many years scientists thought feathers were unique to birds as a great adaption for generating flight. But it seems almost 100 per cent certain that feathers evolved for something else. We just have to figure out what for."

Journal reference: Nature Communications, DOI: 10.1038/ncomms3489

 

[ramonmercado]

Predatory 'king of gore' dinosaur discovered
http://www.bbc.co.uk/news/science-environment-24817884
By Melissa Hogenboom
Science reporter, BBC News

Lythronax argestes

The new predator was on the same evolutionary line as T. rex

A new super-predator dinosaur that roamed the Earth 80 million years ago has been discovered in southern Utah.

It was closely related to its slightly larger relative, Tyrannosaurus rex, but lived earlier, making it the largest living land predator of its time.

Growing to about 30ft (9m) long, the predator has been named Lythronax argestes which means "king of gore".

The research, published in the journal Plos One, highlights once more that the age of discovery is far from over.

The team also hopes this new find will help uncover what the climate was like towards the end of the age of dinosaurs.

"It's always exciting to find new species but what's really significant is what these species tell us about their ancient world," said Randall Irmis, co-author of the study at the Natural History Museum of Utah, US.

"This was a very different place 80 million years ago. It was a very lush, wet, tropical environment and there were no polar ice caps at the time."

Continue reading the main story
Tyrannosaurid dinosaurs

Artist's impression of the new tyrannosaur Lythronax announced by paleontologists
Lythronax belongs to a group of carnivorous dinosaurs called Tyrannosaurids, the same group as the T. rex
They are the greatest carnivores - though not the largest - to have walked the Earth
Lived in the Late Cretaceous Period, between 95-70 million years ago
The new find lived on a strip of land called Laramidia in western North America
This same area was home to a range of species such as the the horned and duck billed dinosaurs
Recently an unusual new species of horned dinosaur with a big nose was also discovered in the area
BBC Nature - Dinosaurs videos, news and facts
Short snout
First discovered in 2009, the partial skeleton included a number of bones from the skull and some from the rest of the body. The fossils were then excavated and studied in the lab.

The new discovery was closely related to T. rex and shows that similar features evolved 10 million years earlier than previously thought.

Lythronax had a short and narrow snout and forward slanting eyes. Like its evolutionary relative, it had a head full of sharp teeth and was a ferocious predator, the largest of its ecosystem.

The team also uncovered the most complete fossils of another named species of Tyrannosaur - Teratophoneus curriei. It was previously only known from a few skull bones but the team now have more than 70% of its skeleton.

"There's a whole diversity of different branches of the Tyrannosaur family tree that are waiting to be found out there," Dr Irmis told BBC News.

It was previously unclear why there were so many different Tyrannosaurid species present in a similar area, as the animals were able to move around freely. The palaeontologists believe this was due to a changing of sea level.

"We think that when the sea level was high it was isolating areas in western North America that caused different species to evolve in isolation and that's why we're finding so many different species," added Dr Irmis.

He explained that the creature had been named the "King of Gore" because of its super-predator status. The second part of its name "argestes" comes from Greek poet Homer's naming of a south-westerly wind.

Lythronax fossil
Lythronax had binocular vision which made it a ferocious hunter
"Tyrannosaurids were the really large predators in their ecosystem. It's fairly certain based on what we can see on their skull, teeth and body size they probably ate whatever they could fit in their mouths," added Dr Irmis.

Apex predator
Another research member of the team, Joseph Sertich of the Denver Museum of Nature and Science, US, explained that the back of its skull was very wide which gave it good hunting eyes.

"One of the things that makes T. rex different from other dinosaurs is that it is able to look forward, it has binocular vision. Lythronax had that feature as well, its field of view could overlap which probably made it a better hunter," Dr Sertich told BBC News.

"It was the apex predator of it's time. It was the oldest advanced Tyrannosaur of its group, which is quite surprising.

"This is the tip of the iceberg. It's amazing what we're finding in southern Utah right now. You can walk over some of the hills and find fossils littering the sides of the slopes," he added.

Mike Benton at the University of Bristol, UK, who was not involved with the study, said the new find was important for understanding patterns of evolution of the Tyrannosaurids.

"Previously, Tyrannosauri origins were uncertain, whether in Asia or North America, and the new find tends to suggest a mainly North American evolution for the group."

Reconstructed skull and skeleton
The specimen discovered was 24ft long but was not a fully grown adult - estimated to be 30ft long

 

[ramonmercado]

Amber Provides New Insights Into the Evolution of Earth's Atmosphere: Low Oxygen Levels for Dinosaurs
http://www.sciencedaily.com/releases/20 ... 081043.htm

The team analyzed amber samples from almost all well-known amber deposits worldwide. This amber originates from the Cretaceous period, an inclusion of foliage of the extinct conifer tree Parataxodium sp. from the Foremost Formation at Grassy Lake, Alberta, Canada. It is approximately 77 million years old. (Credit: Ryan C. McKellar)

Nov. 18, 2013 — An international team of researchers led by Ralf Tappert, University of Innsbruck, reconstructed the composition of Earth's atmosphere of the last 220 million years by analyzing modern and fossil plant resins. The results suggest that atmospheric oxygen was considerably lower in Earth's geological past than previously assumed. This new study questions some of the current theories about the evolution of climate and life, including the causes for the gigantism of dinosaurs.

Scientists encounter big challenges when reconstructing atmospheric compositions in Earth's geological past because of the lack of useable sample material. One of the few organic materials that may preserve reliable data of Earth's geological history over millions of years are fossil resins (e.g. amber). "Compared to other organic matter, amber has the advantage that it remains chemically and isotopically almost unchanged over long periods of geological time," explains Ralf Tappert from the Institute of Mineralogy and Petrography at the University of Innsbruck. The mineralogist and his colleagues from the University of Alberta in Canada and universities in the USA and Spain have produced a comprehensive study of the chemical composition of Earth's atmosphere since the Triassic period.

The study has been published in the journal Geochimica et Cosmochimica Acta. The interdisciplinary team, consisting of mineralogists, paleontologists and geochemists, use the preserving properties of plant resins, caused by polymerization, for their study. "During photosynthesis plants bind atmospheric carbon, whose isotopic composition is preserved in resins over millions of years, and from this, we can infer atmospheric oxygen concentrations," explains Ralf Tappert. The information about oxygen concentration comes from the isotopic composition of carbon or rather from the ratio between the stable carbon isotopes 12C and 13C.

Atmospheric oxygen between 10 and 15 percent

The research team analyzed a total of 538 amber samples from from well-known amber deposits worldwide, with the oldest samples being approximately 220 million years old and recovered from the Dolomites in Italy. The team also compared fossil amber with modern resins to test the validity of the data. The results of this comprehensive study suggest that atmospheric oxygen during most of the past 220 million years was considerably lower than today's 21 percent. "We suggest numbers between 10 and 15 percent," says Tappert. These oxygen concentrations are not only lower than today but also considerably lower than the majority of previous investigations propose for the same time period. For the Cretaceous period (65 -- 145 million years ago), for example, up to 30 percent atmospheric oxygen has been suggested previously.

Effects on climate and environment

The researchers also relate this low atmospheric oxygen to climatic developments in Earth's history. "We found that particularly low oxygen levels coincided with intervals of elevated global temperatures and high carbon dioxide concentrations," explains Tappert. The mineralogist suggests that oxygen may influence carbon dioxide levels and, under certain circumstances, might even accelerate the influx of carbon dioxide into the atmosphere. "Basically, we are dealing here with simple oxidation reactions that are amplified particularly during intervals of high temperatures such as during the Cretaceous period." The researchers, thus, conclude that an increase in carbon dioxide levels caused by extremely strong vulcanism was accompanied by a decrease of atmospheric oxygen. This becomes particularly apparent when looking at the last 50 million years of geological history. Following the results of this study, the comparably low temperatures of the more recent past (i.e. the Ice Ages) may be attributed to the absence of large scale vulcanism events and an increase in atmospheric oxygen.

Oxygen may not be the cause of gigantism

According to the results of the study, oxygen may indirectly influence the climate. This in turn may also affect the evolution of life on Earth. A well-known example are dinosaurs: Many theories about animal gigantism offer high levels of atmospheric oxygen as an explanation. Tappert now suggests to reconsider these theories: "We do not want to negate the influence of oxygen for the evolution of life in general with our study, but the gigantism of dinosaurs cannot be explained by those theories." The research team highly recommends conducting further studies and intends to analyze even older plant resins.

Story Source:

The above story is based on materials provided by University of Innsbruck.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

Journal Reference:

Ralf Tappert, Ryan C. McKellar, Alexander P. Wolfe, Michelle C. Tappert, Jaime Ortega-Blanco, Karlis Muehlenbachs. Stable carbon isotopes of C3 plant resins and ambers record changes in atmospheric oxygen since the Triassic. Geochimica et Cosmochimica Acta, 2013; 121: 240 DOI: 10.1016/j.gca.2013.07.011

 

[ramonmercado]

Dinosaur mummy's fleshy head crest
http://www.bbc.co.uk/nature/25260312
By Ella Davies
Reporter, BBC Nature

Edmontosauraus regalis illustration

A mummified dinosaur provides the first evidence the scaly animals had fleshy head ornaments, scientists say.

The preserved remains of the duck-billed dinosaur Edmontosauraus regalis were discovered in Alberta, Canada.

Analysis revealed the previously unknown feature which experts compared to a rooster's comb.

They suggest the ornaments were used to attract mates in the same way modern birds use bright appendages.

The findings are published in Current Biology.

Continue reading the main story
Dino details

Illustration of hadrosaurs
See the variety of bony crests in duck-billed dinosaur skeletons

What can preserved poo tell us about prehistoric times?

Watch secrets revealed by a fossilised dinosaur nest

"This is the first evidence of an entirely soft-tissue crest for any dinosaur," said lead author Dr Phil Bell from the University of New England, Australia.

"Bony crests are well known but skin rarely fossilises and even when it does, it is almost never found on the skull."

The specimen was discovered by co-author and geologist Frederico Fanti from the University of Bologna, Italy.

"While we were using a rock saw to cut the block down in the field to make it easier to transport, we discovered skin impressions quite by accident but it wasn't until we got the block back to the lab that we realised just how extensive the skin was," explained Dr Bell.

E. regalis is a member of the Hadrosaurid family - also known as the duck-billed dinosaurs.

They were the most common dinosaurs in North America between 75 and 65 million years ago and used their long bills to graze on vegetation.

Preserved Edmontosaurus regalis
The comb structure is the round lump in the centre of the picture, the scales to the left are on the dinosaur's neck. It was preserved with its head rolled back.
Soft tissue is often lost in the process of fossilisation but preserved tissues from hadrosaurs have been found in recent years.

Experts suggest that when an animal was instantly buried in certain sediments, decay was slowed down through a lack of oxygen and soft tissues were mineralised.

This process allows microscopic details and even original organic compounds to be preserved so the remains are sometimes referred to as 'dinosaur mummies'.

Other hadrosaurs are known to have had hollow bone structures on their heads, whereas pterosaurs had smooth crests made of keratin - the hard fibrous proteins responsible for beaks, horns and fingernails.

But the scaly, fleshy structure found in E. regalis "raises the thought-provoking possibility of similar crests among other dinosaurs," according to Dr Bell.

The research team's illustrated reconstruction, that suggests the crest was brightly coloured, is based on evidence of similar appendages seen in the modern world.

"Based on comparisons with living birds, crests like that in Edmontosaurus were probably used to attract mates," said Dr Bell.

"Often, the largest and most brightly coloured crest gets the girl and in the case of herding animals, it probably identified who was the head of the group."

 

[ramonmercado]

Feathers were the exception rather than the rule for dinosaurs
Survey of dinosaur family tree finds that most had scaly skin like reptiles.
http://www.nature.com/news/feathers-wer ... rs-1.14379
Matt Kaplan
27 December 2013

De Agostini Picture Library/Getty Images

The late-Cretaceous Triceratops were among the majority of dinosaurs that had featheless, scaly skins.

Birds evolved from dinosaurs, and dinosaur fossils are often covered with impressions of feathers, which made some palaeontologists speculate whether feathers were a common trait that appeared early in their history. Now a team analysing feathers on the overall dinosaur family tree argues this is taking things too far.


Ten people who mattered in science this year
Why swine flu, and a vaccine against it, may have triggered cases of narcolepsy
Best evidence yet that our Universe is a hologram
Palaeontologists have known for about two decades that theropods, the dinosaur group that contained the likes of Tyrannosaurus and Velociraptor and from which modern birds evolved, were covered in feathery structures from early on in their history.

By contrast, the ornithischian lineage — which contained animals such as Triceratops, Stegosaurus and Ankylosaurus — and the huge, long-necked dinosaurs in the sauropod lineage were considered to be scaly, similar to modern reptiles. Indeed, all evidence pointed in this direction until the discovery, beginning in 20021, 2, of a few ornithischians with filament-like structures in their skin. This led to speculation that feather-like structures were an ancestral trait for all dinosaur groups.

Related stories
Palaeontology: The truth about T. rex
Dust-up over dinosaurs' true colours
Rise of the feathered dinosaurs
More related stories
Keen to know more, palaeontologists Paul Barrett of the Natural History Museum in London and David Evans of the Royal Ontario Museum in Toronto created a database of all known impressions of dinosaur skin tissues. They then identified those that had feathers or feather-like structures, and considered relationships in the dinosaurian family tree.

The results, which Barrett revealed at the Society of Vertebrate Palaeontology’s annual meeting in Los Angeles in late October, indicate that although some ornithischians, such as Psittacosaurus and Tianyulong, had quills or filaments in their skin, the overwhelming majority had scales or armour. Among sauropods, scales were also the norm.

“I’d go so far as to say that all dinosaurs had some sort of genetic trait that made it easy for their skin to sprout filaments, quills and even feathers,” says Barrett. ”But with scales so common throughout the family tree, they still look like they are the ancestral condition.”

The findings provide “a valuable reality check for all of us who have been enthusiastic about suggesting dinosaurs were primitively feathered”, says Richard Butler, a palaeontologist at the University of Birmingham, UK, who was not associated with the study.

Even so, Butler points out that the findings are not set in stone. “We don’t have primitive dinosaurs from the late Triassic and early Jurassic periods preserved in the right conditions for us to find skin or feather impressions,” he says. “This picture could quickly change if we start finding early dinosaurs with feathers on them.”

Nature doi:10.1038/nature.2013.14379

References

Mayr, G., Peters, D. S., Plodowski, G. & Vogel, O. Naturwissenschaften 89, 361–365 (2002).
ArticlePubMedISIChemPort

Zheng, X.-T., You, H.-L., Xu, X. & Dong, Z.-M. Nature 458, 333–336 (2009).
ArticlePubMedISIChemPortShow context
Related stories an

 

[rynner2]

Ichthyosaur skeleton found at base of Dorset cliff

Storms in Dorset over the Christmas period have uncovered a 1.5m (5ft) ichthyosaur skeleton at the base of Black Ven near Charmouth.
Stormy seas have eroded away parts of the Jurassic Coast, making it a "prime time" to find fossils, according to earth science manager Richard Edmonds.

The giant marine reptile fossil was removed on Boxing Day.
It will take hundreds of hours to piece together the ichthyosaur skeleton, which looks similar to a dolphin.

Mr Edmonds, who works for the Jurassic Coast world heritage site team, said he found three ichthyosaur skeletons last year due to increased coastal erosion caused by bad weather.
Normally it could be up to two years between discoveries, he added.

http://www.bbc.co.uk/news/uk-england-dorset-25548426

I'd hardly call 5ft 'giant'!

 

[rynner2]

Ichthyosaur fossil at Charmouth narrowly misses storm destruction

A near-complete ichthyosaur skeleton discovered on the Dorset coast after Christmas storms was hours away from destruction, fossil hunters have said.
Storms uncovered the 1.5m (5ft) fossil at the base of Black Ven near Charmouth on Boxing Day.
The giant marine reptile fossil was painstakingly removed over eight hours, shortly before another storm was due.

Professional fossil hunter Paul Crossley, who helped excavate it, said it was "a beautiful find".
"There was a very difficult, short window before another storm blew in so we were limited for time before it got ploughed out," he said.

With only part of the snout missing, but with most vertebrae and its rib cage in place, Mr Crossley said it was one of only a few ichthyosaur fossils found in such a complete condition on the Jurassic Coast in the past decade.
Ichthyosaurs (literally 'fish-lizards') were predatory dolphin-like reptiles that swam the world's oceans 200 million years ago at the time of the dinosaurs.

The fossilised remains were spotted by hobby collector Alan Saxon, from Chippenham in Wiltshire, who was on a post-Christmas visit to the Jurassic Coast.
Mr Saxon said he hoped the fossil would eventually go on public display
"It was actually easy to spot - I just saw a long black snout against the grey shale. I had a closer look and could see jaws, teeth and backbones," he added.

Mr Saxon, 59, said he was considering the best approach to ensure the fossil was conserved.
"In the long term I'd like it to be available for people to see, especially in the Lyme Regis locality," he said.

Recent storm-force south-westerly winds hitting the crumbling cliffs have produced some of the most conducive conditions for fossil hunting on the beaches around Lyme Regis in several years.
Mr Crossley said: "The word is already out that Lyme Regis is the capital of fossil hunting at the moment, we've seen more people than normal on the beaches.
"We always advise going when the tide is falling and always stay well away from the cliffs and mudslides. Use common sense."

http://www.bbc.co.uk/news/uk-england-dorset-25578510

 

[ramonmercado]

Malaysia: First fossil find a 'Spinosaurid tooth'.
News from Elsewhere...
...as found by BBC Monitoring
http://www.bbc.co.uk/news/blogs-news-fr ... e-26270766

The spinosaurid tooth

The tooth is said to date back to the Cretaceous period

Experts have unveiled Malaysia's first ever dinosaur fossil after nearly two-years of digging, it's been reported.

The find is a 75 million-year-old tooth. Less than an inch long, it is thought to have belonged to a fish-eating predator - a member of the spinosaurid family of dinosaurs, Australia's SBS public service broadcaster reports.

It was found in the central state of Pahang but the exact location is being kept secret to prevent "lawless excavations by private fossil collectors or robbers". Scientists are also hoping are are more such discoveries to be made.

"We currently continue further research and hope to conduct more extensive field investigations that may disclose more significant finds," a statement from the University of Malaya said. The dig was conducted by scientists from the University of Malaya and Japan's Waseda and Kumamoto Universities.

 

[Analis]

Feathers were the exception rather than the rule for dinosaurs
Survey of dinosaur family tree finds that most had scaly skin like reptiles.
http://www.nature.com/news/feathers-wer ... rs-1.14379
Matt Kaplann

Mark Witton provides here a number of interesting thoughts on the matter of fossil skin findings and their consequences on phylogenetic and anatomical deductions :
http://markwitton-com.blogspot.fr/2013/ ... ch-to.html

He has a number of points. His representation of furry pachyrhinosaurs is a bit extreme, and not really likely, but he cleverly demonstrates that it can not be hastily ruled out of hand. While considering that the finding of a skin pattern on a fossil animal implies that its relatives had the same skin pattern seems the most parsimonious assomption, and indeed is in my opinion, such generalization may lead us to make mistakes.

But in the end, Kaplan's article is right to state that only some well preserved fossils would help us to solve the mistery of original dinosaurs outlook. Let's hope that there is a Lägerstatten from the Triassic and Early Jurassic awaiting us somewhere. However, the discussion has already moved for a number of years to the first ornithodirans (dinosaurs, pterosaurs, and their closest relatives), and now even to the early archosaurs, based on genetic evidence.

 

[ramonmercado]

Ferocious dino was European giant
By Jonathan Amos
Science correspondent, BBC News
http://www.bbc.com/news/science-environment-26452266

Artist's impression of Torvosaurus gurneyi

When it roamed what is now Portugal, this dinosaur would have been at the top of the food chain

Scientists in Portugal have identified what they think may have been the largest predator ever to roam across the European landmass.

Fossil bones from the dinosaur were pulled from a cliff at Praia da Vermelha just north of Lisbon.

Known as Torvosaurus gurneyi, this ferocious beast would have been some 10m in length and weighed perhaps 4-5 tonnes.

Its features are described in the latest edition of the Plos One journal.

It was a theropod - the kind of two-legged, meat-eating animal that everyone instantly recognises in something like Tyrannosaurus rex.

But T. gurneyi lived much earlier in time, in the late Jurassic - about 150 million years ago.

"We all know about T. rex, but Tyrannosaurus was a Cretaceous animal," explains co-author Prof Octavio Mateus from the New University of Lisbon.


"Our dinosaur was Jurassic. The difference in age is striking - it's 80 million years. So, when T. rex walked on Earth, Torvosaurus was already a fossil," he told BBC News.

Scientists have now unearthed a number of body parts belonging to Torvosaurus from Portugal's fossil-rich Lourinha rock formation. These specimens even include eggs and embryos.

But it is with this latest description of the dinosaur's upper-jaw that the researchers believe they can put the creature in its proper context.

They say the Portuguese animal is distinct from the Torvosaurus already known from North America.

That fossil "cousin", known as Torvosaurus tanneri, was found in rocks of similar age, from the so-called Morrison formation.

It means that both animals must have shared a common ancestor deeper in time, before the Atlantic Ocean was fully opened.

"One hundred and fifty million years ago, Portugal was already separated from North America and this meant the mechanism of speciation could occur," said lead author Christophe Hendrickx. "And this is why we have a new species of Torvosaurus in Europe."

Size comparison
This diagram gives some sense of how big the animal would have been
One of the most impressive features of the Plos One T. gurneyi find is its teeth - blade-shaped and more than 10cm long.

This indicates it must have been at the top of the food chain when it stomped around the Iberian Peninsula.

"Besides dinosaurs, we had turtles, crocodiles, those flying reptiles we call pterosaurs, and also small mammals," Mr Hendrickx told BBC News.

"And for the flora - it must have been quite luxuriant. A lot of conifers and gingkos. [It would have looked] something like a tropical environment."

Prof Mateus added: "This was an area with a lot of rivers, a lot of fresh water; and a lot of vegetation. So, it would have been good for herbivores, and with herbivores come some carnivores like Torvosaurus."

Although a record-breaker for terrestrial Europe, Torvosaurus is not the largest predatory dinosaur known to science.

Carcharodontosaurus, Giganotosaurus and Tyrannosaurus from other parts of the world, and from the later Cretaceous Period, were all bigger land animals.

And of course there were marine predators in the Jurassic, such as plesiosaurs, that would have rivalled it for size.

The largest known herbivore in Europe was probably a sauropod from Spain whose bones suggest it weighed in excess of 40 tonnes.

Commenting on the Plos One paper, Dr Paul Barrett, from London's Natural History Museum, said: "This new dinosaur highlights surprising similarities between the classic Late Jurassic dinosaur faunas of North America and the more poorly known ecosystems of the same age in western Europe.

"Torvosaurus gurneyi and other dinosaurs from Portugal have many of their closest relatives in the US, suggesting that these two areas must have been linked by occasional land connections at the time when the European and North America species would have been separating from each other."

Upper-jaw part
The upper-jaw bone, or maxilla, has enabled the scientists to put the dinosaur in context

[email protected]. and follow me on Twitter: @BBCAmos

 

[ramonmercado]

Dinosaur skull may reveal T. rex's smaller cousin from the north
March 12th, 2014 in Other Sciences / Archaeology & Fossils

Paleontologists from the Perot Museum of Nature and Science in Dallas have discovered a new genus and species of a pygmy tyrannosaur that once roamed the ancient Arctic lands of Northern Alaska. The animal has been formally named Nanuqsaurus hoglundi. Credit: Karen Carr

Paleontologists from the Perot Museum of Nature and Science in Dallas have discovered a new genus and species of a pygmy tyrannosaur that once roamed the ancient Arctic lands of Northern Alaska. The animal has been formally named Nanuqsaurus hoglundi. Credit: Karen Carr

A 70 million year old fossil found in the Late Cretaceous sediments of Alaska reveals a new small tyrannosaur, according to a paper published in the open-access journal PLOS ONE on March 12, 2014 by co-authors Anthony Fiorillo and Ronald S. Tykoski from Perot Museum of Nature and Science, Texas, and colleagues.

Tyrannosaurs, the lineage of carnivorous theropod ("beast feet") dinosaurs that include T. rex, have captivated our attention, but the majority of our knowledge about this group comes from fossils from low- to mid-latitudes of North America and Asia. In this study, scientists analyzed the partial skull roof, maxilla, and jaw, recovered from Prince Creek Formation in Northern Alaska, of a dinosaur originally believed to belong to a different species, and then compared the fossils to known tyrannosaurine species.

According to the results of the authors' analysis, the cranial bones represent Nanuqsaurus hoglundi, a new tyrannosaurine species closely related to two other tyrannosaurides, Tarbosaurus and Tyrannosaurus. This new dinosaur is estimated to be relatively small, with an adult skull length estimated at 25 inches, compared to 60 inches for T. rex. The new species likely inhabited a seasonally extreme, high-latitude continental environment on the northernmost edge of Cretaceous North America. The authors suggest that the smaller body size of N. hoglundi compared to most tyrannosaurids from lower latitudes may reflect an adaptation to variability in resources in the arctic seasons. Further diversification may stem from the dinosaurs' partial isolation in the north by land barriers, such as the east-west running Brooks Range. Although the preserved elements of N. hoglundi are fragments, the authors point to morphological data to provide support for its place among derived tyrannosaurines. This discovery may provide new insights into the adaptability and evolution of tyrannosaurs in a different environment, the Arctic.

"The 'pygmy tyrannosaur' alone is really cool because it tells us something about what the environment was like in the ancient Arctic," said Fiorillo. "But what makes this discovery even more exciting is that Nanuqsaurus hoglundi also tells us about the biological richness of the ancient polar world during a time when the Earth was very warm compared to today."

More information: Fiorillo AR, Tykoski RS (2014) A Diminutive New Tyrannosaur from the Top of the World. PLoS ONE 9(3): e91287. DOI: 10.1371/journal.pone.0091287

Provided by Public Library of Science

"Dinosaur skull may reveal T. rex's smaller cousin from the north." March 12th, 2014. http://phys.org/news/2014-03-dinosaur-s ... aller.html

 

[ramonmercado]

Anzu wyliei: Scientists announce new dinosaur discovery
By Jane O'Brien
BBC News, Washington
http://www.bbc.com/news/world-us-canada-26653799

The BBC's Jane O'Brien speaks to Smithsonian dinosaur expert Hans Sues about the discovery of the "chicken from hell"

US scientists have announced the discovery of a new species of dinosaur. Its fossils offer further clues to how the dinosaurs became extinct 66 million years ago.

Anzu wyliei is a strange, bird-like creature that has a bony crest on top of a beaky head and a long tail like a lizard.

The animal was identified from the partial remains of three skeletons collected in North and South Dakota.

It is reported in PLoS ONE journal.

Continue reading the main story
“
Start Quote

It's clear that dinosaurs were still quite diverse until the very end”

Hans Sues
Smithsonian Institution
"We had inklings that there might be such a creature out there, but now with these bones we have 80% of the skeleton and can really look in detail at the structure of this animal and make inferences about its biology," says Hans Sues, curator of vertebrate palaeontology in the department of palaeobiology at the Smithsonian's National Museum of Natural History in Washington DC.

"Anzu is really bizarre, even by dinosaur standards.

"The skull has this extraordinarily tall and thin crest with a snout and a huge beak with sharp edges and a strange sliding jaw joint," that could be used to cut up vegetation and meat, he says.

Diverse communities
The size of a small car, the dinosaur also had claws and feathers on its upper arms. It belongs to a group of dinosaurs known as Oviraptorosauria. Most evidence of their existence comes from fossils discovered in Central and East Asia.

The Anzu bones are the first detailed evidence that oviraptorosaurs also lived in North America.

The specimens were found in a geological formation known as Hell Creek, which has been extensively explored and is the source of many dinosaur fossils discovered in North America.

Scientists have nicknamed it "the chicken from Hell" because of its appearance and where it was found.

The site is important because it was formed in the last two million years of the Cretaceous Period, just before dinosaurs were wiped out by an asteroid strike.

Many researchers have argued that the dinosaurs were already in decline because of climate change. But according to Dr Sues and his team, the discovery of Anzu offers further proof that many species were still evolving and dinosaur communities were diverse and flourishing.

Skull
The Anzu wyliei skull, shown in a reconstruction, featured a bony crest
"This is consistent with the idea that a mass extinction was caused by the great asteroid impact 66 million years ago. It's clear that dinosaurs were still quite diverse until the very end," says Dr Sues.

A thousand species of dinosaurs have been discovered so far. Scientists believe there are many thousands more waiting to be identified, even in heavily excavated formations such as Hell Creek.

The discovery of another species from the site was announced in December last year - a small raptor called Acheroraptor temertyorum. And scientists have only begun to explore potential dinosaur graves in Central Asia.

Bones in ground
But there's no magic formula for discovery, according to Tyler Lyson, who found one of the Anzu skeletons in 2009 on his uncle's ranch in North Dakota.

"We were just walking along when we saw some dinosaur bones poking out of the ground," he recalls.

"I knew right away that they belonged to a meat-eating dinosaur because meat-eating dinosaurs have hollow bones, and these bones were hollow. We carefully made a plaster jacket to wrap the specimen and get it back to the lab. After several hours cleaning it, we knew we had found something new. It was unlike anything else we had ever seen before."

Dr Lyson is part of the Smithsonian team and the founder of the Marmarth Research Foundation, which promotes the study of fossils. He discovered his first dinosaur bone when he was just six years old. The other two Anzu skeletons, which include a skull, were discovered by private collectors.

"You just have to spend time out there," he says. "The bones come to the surface and then break up into little pieces. You get a trail of broken bits of bone which you follow, and if you're lucky you'll see bones sticking out of the side of the hill - and that's exactly what we found here."

Although the Anzu skeletons were discovered several years ago, scientists work in "deep time", says Dr Lyson. Bones have to be catalogued and compared with other specimens while scientific evidence has to be peer-reviewed. It can take a decade before any official announcement is made.

All three Anzu skeletons are housed at the Carnegie Museum of Natural History in Pittsburgh, which collaborated with the Smithsonian to identify the new species.

 

[Analis]

But in the end, Kaplan's article is right to state that only some well preserved fossils would help us to solve the mistery of original dinosaurs outlook. Let's hope that there is a Lägerstatten from the Triassic and Early Jurassic awaiting us somewhere.

Hmmm... :
http://dinoweb.ucoz.ru/news/feather_lik ... 3-10-12-14

FEATHER-LIKE STRUCTURES AND SCALES IN A JURASSIC NEORNITHISCHIAN DINOSAUR FROM SIBERIA

GODEFROIT, Pascal, Institut Royal des Sciences Naturelles de Belgique, Brussels,
Belgium; SINITSA, Sofia, Institute of Natural Resources, Ecology and Cryology, SB
RAS, Chita, Russia; DHOUAILLY, Danielle, Université Joseph Fournier, La Tronche,
France; BOLOTSKY, Yuri, Institute of Geology and Nature Management, FEB RAS,
Blagoveschensk, Russia; SIZOV, Alexander, Institute of the Earth’s Crust, SB RAS,
Irkutsk, Russia
Recent discoveries in Middle–Late Jurassic and Early Cretaceous deposits from
northeastern China have revealed that numerous theropod dinosaurs were covered by
feathers. Furthermore, filamentous integumentary structures were also recently described
in rare Early Cretaceous ornithischian dinosaurs from Liaoning Province in China.
Whether these filaments can be regarded as epidermal and therefore part of the
evolutionary lineage towards feathers remains controversial. Here we describe a new
basal neornithischian dinosaur, based on isolated bones and partial skeletons collected in
two monospecific bonebeds from the Middle–Late Jurassic Kulinda locality in the
Transbaikal region (Russia). Varied integumentary structures were found directly
associated with skeletal elements, supporting the hypothesis that simple filamentous
feathers, as well as compound feather-like structures comparable to those in theropods,
were widespread amongst the whole dinosaur clade. Moreover, scales along the distal
tibia and on the foot closely resemble the secondarily-appearing pedal scales in extant
birds. More surprisingly, dorso-ventral movements of the tail were prevented by large
imbricated scales on its dorsal surface. It is hypothesized that, at the same time early
feathers evolved within the whole dinosaur clade, genetic mechanisms limiting the
growth of long epidermal structures on the distal portion of the hind limb and on the tail
were selected as they facilitate bipedal terrestrial locomotion.
http://dinoweb.ucoz.ru/forum/29-1790-1

The rumour had been running for a few months, but now an article seems to confirm it. This discovery of an early neornitischian would confirm that hair-like structures were present among various basal ornitischians, giving more weight to the assumption that they were shared by the last common ancestor to all dinosaurs. More surprisingly, it would evidence the first discovery of complex feathers outside theropods, which would force to revise even the most audacious theories. Their hypothesis that the facilitation of bipedal locomotion explains the presence of scales on the distal limb and the tail is interesting, but the fact that this condition is also matched on many mamals would suggest that bipedy is not a crucial condition.

 

[ramonmercado]

Vid & images at link.

New Tyrannosaur named 'Pinocchio rex'

Qianzhousaurus hunting a small feathered dinosaur Nankangia

Pinocchio was smaller than T. rex but its nose was a third longer - perhaps for a different hunting strategy

A new type of Tyrannosaur with a very long nose has been nicknamed "Pinocchio rex".

The ferocious carnivore, nine metres long with a distinctive horny snout, was a cousin of Tyrannosaurus rex.

Its skeleton was dug up in a Chinese construction site and identified by scientists at Edinburgh University, UK.

Continue reading the main story
“
Start Quote

This is the slam dunk we needed - the long-snouted tyrannosaurs were real”

Dr Steve Brusatte
Edinburgh University
How to move a T-Rex dinosaur
The 66-million-year-old predator, officially named Qianzhousaurus sinensis, is described in Nature Communications.

"Pinocchio" looked very different to other tyrannosaurs.

"It had the familiar toothy grin of T. rex, but its snout was long and slender, with a row of horns on top," said Edinburgh's Dr Steve Brusatte.

"It might have looked a little comical, but it would have been as deadly as any other tyrannosaur, and maybe even a little faster and stealthier.

"We thought it needed a nickname, and the long snout made us think of Pinocchio's long nose."

Researchers now think several different tyrannosaurs lived and hunted alongside each other in Asia during the late Cretaceous Period, the last days of the dinosaurs.

Skull of Qianzhousaurus
The enormous Tarbosaurus (up to 13m) had deep and powerful jaws like T. rex - strong enough to crush the bones of giant herbivores.

Continue reading the main story
“
Start Quote

This new dinosaur breaks the mould. Perhaps it had a faster bite and hunted in a different way”

Dr Steve Brusatte
Edinburgh University
The thinner teeth and lighter skeleton of Qianzhousaurus suggest it hunted smaller creatures, such as lizards and feathered dinosaurs. But at nine metres tall and weighing almost a tonne, it was still a gigantic carnivore.

"You wouldn't want to run into either of these guys," said Dr Brusatte.

'Weird features'
Pinocchio's snout was 35% longer than other dinosaurs of its size. So, why the long face?

"The truth is we don't know yet. But it must've been doing something different," Dr Brusatte told BBC News.

"The iconic picture of a tyrannosaur is T. Rex, the biggest, baddest dinosaur of all.

"But this new species was lighter, less muscular. It breaks the mould. Perhaps it had a faster bite and hunted in a different way."

Prof Junchang Lu and Dr Steve Brusatte at construction site where dinosaur fossil discovered
Prof Junchang Lu and Dr Steve Brusatte at the discovery site
The discovery of "Pinocchio" settles an argument over a series of strange new fossil finds.

In recent years, two tyrannosaurs with unusually prominent proboscises were dug up in Mongolia, and named Alioramus.

The horny-snouted predators appeared to come from an entirely new branch of the tyrannosaur family.


Dr Steve Brusatte: It would have "been quicker and more agile than a T-Rex"
"The trouble was, they were both juveniles. So it was possible their long snouts were just a weird transient feature that grows out in adults," said Dr Brusatte, an expert in tyrannosaur evolution.

But this new Qianzhousaurus specimen is an almost fully mature adult. It was found largely intact and remarkably well preserved by road construction workers near Ganzhou in southern China.

"It's twice the size of the juveniles, and yet it still shows the same features - including the distinctive horns," said Dr Brusatte.

"This is the slam dunk we needed: the long-snouted tyrannosaurs were real."

Palaeontologists are now confident that Qianzhousaurus and Alioramus are part of a new subgroup of tyrannosaurs with elongated skulls.

Their discovery from Mongolia to southern China suggests these "second tier" carnivores were widely distributed, according to Prof Junchang Lu of the Chinese Academy of Geological Sciences, a co-author on the paper.

"Although we are only starting to learn about them, the long-snouted tyrannosaurs were apparently one of the main groups of predatory dinosaurs in Asia," he said.

With these "weird" creatures now accepted as being part of a whole family, more and more of their long-snouted relatives are expected to be unearthed.

As for the riddle of Pinocchio's nose, the scientists hope to solve it via biomechanical studies of its jaw - which may hint at its feeding habits.
http://www.bbc.com/news/science-environment-27296357

 

[rynner2]

'Biggest dinosaur ever' discovered
By James Morgan, Science reporter, BBC News

Fossilised bones of a dinosaur believed to be the largest creature ever to walk the Earth have been unearthed in Argentina, palaeontologists say.
Based on its huge thigh bones, it was 40m (130ft) long and 20m (65ft) tall.
Weighing in at 77 tonnes, it was as heavy as 14 African elephants, and seven tonnes heavier than the previous record holder, Argentinosaurus.
Scientists believe it is a new species of titanosaur - an enormous herbivore dating from the Late Cretaceous period.

A local farm worker first stumbled on the remains in the desert near La Flecha, about 250km (135 miles) west of Trelew, Patagonia
[video: Dr Diego Pol explains how the weight of the dinosaur was calculated]

A film crew from the BBC Natural History Unit was there to capture the moment the scientists realised exactly how big their discovery was.
By measuring the length and circumference of the largest femur (thigh bone), they calculated the animal weighed 77 tonnes.
"Given the size of these bones, which surpass any of the previously known giant animals, the new dinosaur is the largest animal known that walked on Earth," the researchers told BBC News.
"Its length, from its head to the tip of its tail, was 40m.
"Standing with its neck up, it was about 20m high - equal to a seven-storey building."

etc...

http://www.bbc.co.uk/news/science-environment-27441156