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ramonmercado Psycho Punk
Joined: 19 Aug 2003 Total posts: 17933 Location: Dublin Gender: Male |
 Posted: 24-03-2013 03:26 Post subject: |
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| Quote: | Crow-Size Pterosaur Named After 9-Year-Old Fossil Hunter
http://news.nationalgeographic.com/news/2013/13/130321-vectidraco-daisymorrisae-pterosaurs-dinosaurs-science-animals/?utm_source=Facebook&utm_medium=Social&utm_content=link_fb20130323news-dinokid&utm_campaign=Content
Newfound flying reptile is named after nine-year-old Daisy Morris.
Illustration of the new species of pterosaur—Vectidraco daisymorrisae.
Illustration courtesy University of Southampton
Daisy Morris. Photograph courtesy University of Southampton
Ker Than
for National Geographic News
Published March 21, 2013
A new species of crow-size pterosaur has been named in honor of the nine-year-old fossil hunter who discovered it, a new study says.
The new species of pterosaur—a type of flying reptile that lived alongside the dinosaurs—was dubbed Vectidraco daisymorrisae after U.K. youngster Daisy Morris.
While exploring the U.K.'s Isle of Wight (map) in 2008, the then-five-year-old Morris came across blackened "bones sticking out of the sand," according to the BBC. (Vectidraco means "dragon from the Isle of Wight" in Latin.)
The Morris family brought the fossil to paleontologist Martin Simpson at the University of Southampton, who, with the help of colleagues, identified it as a new species. (Also see "New Giant Flying Reptile Found; Hunted on Foot?")
"In pterosaurs, certain parts of the skeleton, especially the skull and the pelvis, are really distinct between different [species]," explained Andrew Farke, a paleontologist at the Raymond M. Alf Museum of Paleontology in Claremont, California, and editor of the new study in PLoS ONE.
The newfound creature also belonged to a group of pterosaurs called the azhdarchoids, which, "in my opinion, are among the most interesting of pterosaurs," study co-author Darren Naish, also of Southampton University, said in a statement.
"All are from the Cretaceous, all are toothless, and many—perhaps all—were especially well adapted for life in terrestrial environments like woodlands, tropical forests, and floodplains," he said. (Related: "Pterosaur 'Runway' Found; Shows Birdlike Landing Style.")
New Pterosaur Was Expert Flyer
From the size of the pelvis, Simpson and his team estimate V. daisymorrisae had a wingspan of about 2.5 feet (75 centimeters) and was just over a foot (35 centimeters) from snout to tail, making it about the size of a gull or large crow.
V. daisymorrisae was a diminutive cousin of Quetzalcoatlus, which had a wingspan of more than 30 feet (10 meters) and was one of the largest flying creatures to have ever lived. (Watch a video of the "flying monster" Quetzalcoatlus.)
The England that V. daisymorrisae lived in 145 to 65 million years ago was also very different than today. It "was presumably quite a bit warmer then," Farke said, "and filled with lush vegetation."
If the new pterosaur was anything like its relatives, it probably had a head crest, was a reasonably good walker and runner on the ground, and could expertly fly through dense forests.
Daisy and the Dragon
More than a new species came out of Morris's fossil-collecting adventure: She also inspired study co-author Simpson to write a children's book entitled Daisy and the Isle of Wight Dragon. (Take National Geographic's dinosaur quiz.)
"The story highlights the special relationship between amateurs, academics, and curators, in bringing these important finds to the attention of the scientific world," Simpson said in a statement.
"It also shows that, continuing a long tradition in paleontology, major discoveries can be made by amateurs—often by being in the right place at the right time."
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| ramonmercado Psycho Punk
Joined: 19 Aug 2003 Total posts: 17933 Location: Dublin Gender: Male |
| Posted: 20-04-2013 23:10 Post subject: |
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| Quote: | Dinosaur 'fills fossil record gap'
By Helen Briggs
BBC News
http://www.bbc.co.uk/news/science-environment-22210435
The discovery site of the animal
Dinosaur fossils unearthed in Madagascar are of a new species that roamed the Earth about 90 million years ago, say US researchers.
The remains date back to a time when India and Madagascar were one landmass cut off from the rest of the world.
Revealing the discovery in the journal PLOS ONE, scientists say the dinosaur was a bi-pedal meat-eater about the size of a large cow.
It has been named Dahalokely tokana, which means "lonely small bandit".
Madagascar is a treasure trove for palaeontologists, yielding thousands of well-preserved fossils.
Continue reading the main story
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This just reinforces the importance of exploring new areas around the world where undiscovered dinosaur species are still waiting”
Joe Sertich
Denver Museum of Nature and Science
But the latest discovery is the first new dinosaur species unearthed on the island in almost a decade.
Its Malagasy name refers to its carnivorous diet and isolation on a landmass in the middle of the ocean.
The discovery fills a gap in the fossil record and raises intriguing questions about the evolution of animals on both Madagascar and India, which separated at about the time this newly identified creature walked the Earth.
Andrew Farke of the Raymond M Alf Museum of Paleontology in Claremont, California, says it belongs to a group called the Abelisauridae, which were common to the southern continents.
He told BBC News: "The most intriguing thing for me is that it fills a major gap in what we know about the history of dinosaurs in Madagascar.
"It shortens it by about 20 million years. It would have been a meat-eater, walking on two legs about the size of a large cow, with a tail."
Joe Sertich, curator of dinosaurs at the Denver Museum of Nature and Science, who discovered the dinosaur, said it was closely related to well-known dinosaurs from southern continents.
"This just reinforces the importance of exploring new areas around the world where undiscovered dinosaur species are still waiting." |
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| ramonmercado Psycho Punk
Joined: 19 Aug 2003 Total posts: 17933 Location: Dublin Gender: Male |
| Posted: 08-05-2013 23:23 Post subject: |
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| Quote: | 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
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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. |
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| ramonmercado Psycho Punk
Joined: 19 Aug 2003 Total posts: 17933 Location: Dublin Gender: Male |
| Posted: 18-05-2013 02:07 Post subject: |
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Gives a whole new meaning to dinosaur attitudes.
| Quote: | Mum and Dad Dinosaurs Shared the Work
http://www.sciencedaily.com/releases/2013/05/130514213109.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.
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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 |
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| tonyblair11 Joined: 28 Jan 2002 Total posts: 2080 |
| Posted: 18-05-2013 04:39 Post subject: |
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The egg came first!  |
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| ramonmercado Psycho Punk
Joined: 19 Aug 2003 Total posts: 17933 Location: Dublin Gender: Male |
| Posted: 21-05-2013 01:35 Post subject: |
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| Quote: | 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-brain-teaser-reveals-patterns.html |
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| ramonmercado Psycho Punk
Joined: 19 Aug 2003 Total posts: 17933 Location: Dublin Gender: Male |
| Posted: 22-05-2013 19:01 Post subject: |
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More refined table manners?
| Quote: | Allosaurus Fed More Like a Falcon Than a Crocodile: Engineering, Anatomy Work Reveals Differences in Dinosaur Feeding Styles
http://www.sciencedaily.com/releases/2013/05/130521152638.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) |
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| ramonmercado Psycho Punk
Joined: 19 Aug 2003 Total posts: 17933 Location: Dublin Gender: Male |
| Posted: 30-06-2013 23:53 Post subject: |
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How 'Parrot Dinosaur' Switched from Four Feet to Two as It Grew
http://www.sciencedaily.com/releases/2013/06/130628092147.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 |
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| ramonmercado Psycho Punk
Joined: 19 Aug 2003 Total posts: 17933 Location: Dublin Gender: Male |
| Posted: 14-07-2013 20:08 Post subject: |
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Dinosaurs, Diets and Ecological Niches: Study Shows Recipe for Success
http://www.sciencedaily.com/releases/2013/07/130710183640.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 |
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| ramonmercado Psycho Punk
Joined: 19 Aug 2003 Total posts: 17933 Location: Dublin Gender: Male |
| Posted: 17-07-2013 22:41 Post subject: |
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| Quote: | 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. |
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| ramonmercado Psycho Punk
Joined: 19 Aug 2003 Total posts: 17933 Location: Dublin Gender: Male |
| Posted: 18-07-2013 00:42 Post subject: |
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| Quote: | 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-eating-dinosaurs-teeth.html |
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| ramonmercado Psycho Punk
Joined: 19 Aug 2003 Total posts: 17933 Location: Dublin Gender: Male |
| Posted: 19-07-2013 23:20 Post subject: |
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| Quote: |
New Evidence for Warm-Blooded Dinosaurs
http://www.sciencedaily.com/releases/2013/07/130717194948.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 |
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| ramonmercado Psycho Punk
Joined: 19 Aug 2003 Total posts: 17933 Location: Dublin Gender: Male |
| Posted: 19-07-2013 23:28 Post subject: |
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| Quote: |
Rare Fossil of Late Cretaceous Plesiosaur Discovered
http://www.sciencedaily.com/releases/2013/07/130716161916.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. |
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| ramonmercado Psycho Punk
Joined: 19 Aug 2003 Total posts: 17933 Location: Dublin Gender: Male |
| Posted: 28-07-2013 17:37 Post subject: |
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| Quote: | Paleontologists discover dinosaur tail in northern Mexico
http://www.newsdaily.com/article/7e8b4659ebbe54dce611a9ed8d2437ac/paleontologists-discover-dinosaur-tail-in-northern-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 |
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| ramonmercado Psycho Punk
Joined: 19 Aug 2003 Total posts: 17933 Location: Dublin Gender: Male |
| Posted: 01-08-2013 14:06 Post subject: |
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| Quote: | 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." |
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