Sinosauropteryx dinosaurs, new study


This video says about itself:

Dinosaur May Have Looked Like a Raccoon | National Geographic

30 October 2017

A new study of the Sinosauropteryx fossil may shed some light on its appearance and habitat.

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Unusual herbivorous dinosaur discovery


This video says about itself:

op 26 October 2017

An ‘ugly’ dinosaur with huge scissor-style teeth that roamed the south of France 80 million years ago has been discovered by scientists.The plant eater – which grew to more than 16 feet long – had an unusually short face with powerful jaws that enabled it to snack on tough riverside palm trees.Its two-and-a-half inch teeth worked ‘like a pair of scissors’ as it chewed the hard foliage, before swallowing.

Matheronodon provincialis has been identified as a member of rhabdodontids – a group of herbivorous bipedal dinosaurs – from the late Campanian period about 84 to 72 million years ago. They were descendants of the iguanodontian dinosaurs from the Upper Jurassic.

By Helen Thompson, 4:00pm, October 26, 2017:

New dinosaur sported a curious set of chompers

Fossils discovered in France linked to previously unknown Cretaceous species

An ancient vegetarian dinosaur from the French countryside has given paleontologists something to sink their teeth into.

The most striking feature of a new species of rhabdodontid that lived from 84 million to 72 million years ago is its oversized, scissorslike teeth, paleontologist Pascal Godefroit, of the Royal Belgian Institute of Natural Sciences in Brussels, and his colleagues report October 26 in Scientific Reports. Compared with other dinos of its kind, Matheronodon provincialis’ teeth were at least twice as large but fewer in number. Some teeth reached up to 6 centimeters long, while others grew up to 5 centimeters wide. They looked like a caricature of normal rhabdodontid teeth, Godefroit says.

Of hundreds of fossils unearthed over the last two decades at a site called Velaux-La Bastide Neuve in the French countryside, a handful of jaw bones and teeth now have been linked to this new species, Matheronodon provincialis. The toothy dino belongs to a group of herbivorous, bipedal dinosaurs common in the Cretaceous Period. Rhabdodontids sported bladelike teeth, and likely noshed on the tough woody tissue parts of plants. Palm trees, common in Europe at the time, might have been on the menu.

Rhabdodontid teeth have ridges covered by a thick layer of enamel on one side and little to no ridges or enamel on the other. Teeth in the upper jaw have more ridges and enamel on the outer edge, while the reverse is true for bottom teeth. A closer look at the microstructure of M. provincialis’ teeth revealed an exaggerated version of this — many more ridges and lopsided enamel coating. Enamel typically protects from wear and tear, so chewing would have sharpened the dino’s teeth. “They operated like self-sharpening serrated scissors,” Godefroit says.

Big carnivorous dinosaur discovery in Lesotho


This 25 October 2017 video says about itself:

A dinosaur as big as a bus roamed southern Africa 200 million years ago, scientists have revealed thanks to the discovery of several huge three-toed footprints.

From the University of Manchester in England:

‘Mega-carnivore’ dinosaur roamed southern Africa 200 million years ago

October 25, 2017

An international team of scientists has discovered the first evidence that a huge carnivorous dinosaur roamed southern Africa 200 million year ago.

The team, which includes researchers from The University of Manchester, University of Cape Town, South Africa, and Universidade de São Paulo, Brazil, have found several three-toed footprints measuring 57cm long and 50cm wide.

This means the dinosaur would have an estimated body length of around nine metres (30 feet) and be a little less than three metres tall at the hip. That’s four times the size of a lion, which is currently the largest carnivore in southern Africa.

The footprints belong to a new species, named Kayentapus ambrokholohali, which is part of the group of dinosaurs called “megatheropod.” The term “Megatheropods” describes the giant two-legged carnivorous dinosaurs, such as the iconic Tyrannosaurus rex (T. rex) which fossil evidence shows was around 12 metres long.

This study, which is published in PLOS ONE, also reveals that these footprints make up the largest theropod tracks in Africa.

The tracks were found on an ancient land surface, known as a palaeosurface, in the Maseru District of Lesotho, a small country in southern Africa. The surface is covered in 200 million years old ‘current-ripple marks’ and ‘desiccation cracks’ which are signs of a prehistoric watering hole or river bank.

Dr Fabien Knoll, Senior Research Fellow at The University of Manchester, said: ‘The latest discovery is very exciting and sheds new light on the kind of carnivore that roamed what is now southern Africa.

‘That’s because it is the first evidence of an extremely large meat-eating animal roaming a landscape otherwise dominated by a variety of herbivorous, omnivorous and much smaller carnivorous dinosaurs. It really would have been top of the food chain.’

What makes the discovery even more important is that these footprints date back to the Early Jurassic epoch, when it was thought the size of most theropod dinosaurs was considerably smaller. On average they were previously thought to be around three to five metres in body length, with some records showing they may have reached seven metres at the very most. It is only much later in the Jurassic and during the Cretaceous, which starts 145 million years ago, that truly large forms of theropods, such as T. rex, appear in body and trace fossil records.

Dr Lara Sciscio, postdoctoral Research Fellow at the University of Cape Town, said: ‘This discovery marks the first occurrence of very large carnivorous dinosaurs in the Early Jurassic of southern Gondwana — the prehistoric continent which would later break up and become Africa and other landmasses. This makes it a significant find. Globally, these large tracks are very rare. There is only one other known site similar in age and sized tracks, which is in Poland.’

The ancient surface where these footprints were found is also covered with the tracks of much smaller theropod dinosaurs.

Dr Knoll added: ‘In South Africa, Lesotho, Zimbabwe and Namibia, there is good record of theropod footprints from the Late Triassic and Early Jurassic epochs. In fact, there are numerous palaeosurfaces where footprints and even tail and body impressions of these, and other animals, can be found. But now we have evidence this region of Africa was also home to a mega-carnivore.’

T. rex’s silly-looking arms were built for slashing. Robust bones and bearlike claws suggest the dino’s ridiculously small limbs were far from useless. By Carolyn Gramling. 3:30pm, October 25, 2017.

Cretaceous dinosaur discovery in Uzbekistan


This 2013 video is called Alvarezsaurus-the fast dino.

From PLOS ONE:

Alvarezsaurid dinosaur from the late Cretaceous found in Uzbekistan

Several distinctive bones identify this rare theropod

October 25, 2017

Bones from an Alvarezsaurid dinosaur were discovered in Uzbekistan and could shed light on the evolution and origin of the species, according to a study published October 25, 2017 in the open-access journal PLOS ONE by Alexander Averianov of Zoological Institute of the Russian Academy of Sciences, Russia and Hans-Dieter Sues of the Smithsonian Institution, USA.

Previous studies have described Alvarezsauridae as small, long-legged, bipedal dinosaurs with short forelimbs that featured bird-like hands. Since Alvarezsaurid remains are extremely rare, there is plenty to learn about the evolution of this species.

The authors of this study analyzed previously excavated Alvarezsaurid remains from the Turonian Bissekty Formation of Uzbekistan. They examined the vertebrae, the bird-like bone that fuses the wrist and knuckle known as the carpometacarpus, and pieces of what would be the fingers or toes, known as the phalanx. They then measured and compared the shapes and sizes of these bones with those from similar species from the literature.

The authors state that the characteristics for the Alvarezsaurid bones are so distinctive that it could be identified just from the seven bones collected at the Bissekty Formation. These distinctive features included rounded vertebrae located close to the tail, a large and depressed second metacarpal, and a robust second digit with a claw-like end.

While there are competing theories about where the Alvarezsaurid originated, the authors suggest that the discovery of an Alvarezsaurid at this site in Uzbekistan indicates that this group had an evolutionary history in Asia and provides evidence that this continent could have been where the clade originated.

Lead author Hans Sues says: “Our paper reports the discovery of the earliest known alvarezsaurid dinosaur from the Northern Hemisphere, based on 90-million-year-old fossils from Central Asia. Alvarezsaurids were unusual small predatory dinosaurs that had very short but powerfuly built arms that ended in a single large digit.”

Tyrannosaur discovery in Utah, USA


This 2015 video from the USA says about itself:

“Teratophoneus” is a genus of carnivorous tyrannosaurid theropod dinosaur which lived during the late Cretaceous period in what is now Utah, USA. It is known from an incomplete skull and postcranial skeleton recovered from the Kaiparowits Formation. “Teratophoneus” was named by Thomas D. Carr, Thomas E. Williamson, Brooks B. Britt and Ken Stadtman in 2011 and the type species is “T. curriei”. The generic name is derived from Greek “teras”, “monster”, and “phoneus”, “murderer”. The specific name honors Philip J. Currie.

From the University of Utah in the USA:

New tyrannosaur fossil is most complete found in Southwestern US

Researchers are amazed to find nearly complete skeleton with many bones in life position

October 19, 2017

A remarkable new fossilized skeleton of a tyrannosaur discovered in the Bureau of Land Management’s Grand Staircase-Escalante National Monument (GSENM) in southern Utah was airlifted by helicopter Sunday, Oct 15, from a remote field site, and delivered to the Natural History Museum of Utah where it will be uncovered, prepared, and studied. The fossil is approximately 76 million years old and is most likely an individual of the species Teratophoneus curriei, one of Utah‘s ferocious tyrannosaurs that walked western North America between 66 and 90 million years ago during the Late Cretaceous Period.

“With at least 75 percent of its bones preserved, this is the most complete skeleton of a tyrannosaur ever discovered in the southwestern US,” said Dr. Randall Irmis, curator of paleontology at the Museum and associate professor in the Department of Geology and Geophysics at the University of Utah. “We are eager to get a closer look at this fossil to learn more about the southern tyrannosaur’s anatomy, biology, and evolution.”

GSENM Paleontologist Dr. Alan Titus discovered the fossil in July 2015 in the Kaiparowits Formation, part of the central plateau region of the monument. Particularly notable is that the fossil includes a nearly complete skull. Scientists hypothesize that this tyrannosaur was buried either in a river channel or by a flooding event on the floodplain, keeping the skeleton intact.

“The monument is a complex mix of topography — from high desert to badlands — and most of the surface area is exposed rock, making it rich grounds for new discoveries, said Titus. “And we’re not just finding dinosaurs, but also crocodiles, turtles, mammals, amphibians, fish, invertebrates, and plant fossils — remains of a unique ecosystem not found anywhere else in the world,” said Titus.

Although many tyrannosaur fossils have been found over the last one hundred years in the northern Great Plains region of the northern US and Canada, until relatively recently, little was known about them in the southern US. This discovery, and the resulting research, will continue to cement the monument as a key place for understanding the group’s southern history, which appears to have followed a different path than that of their northern counterparts.

This southern tyrannosaur fossil is thought to be a sub-adult individual, 12-15 years old, 17-20 feet long, and with a relatively short head, unlike the typically longer-snouted look of northern tyrannosaurs.

Collecting such fossils from the monument can be unusually challenging. “Many areas are so remote that often we need to have supplies dropped in and the crew hikes in,” said Irmis. For this particular field site, Museum and monument crews back-packed in, carrying all of the supplies they needed to excavate the fossil, such as plaster, water and tools to work at the site for several weeks. The crews conducted a three-week excavation in early May 2017, and continued work during the past two weeks until the specimen was ready to be airlifted out.

Irmis said with the help of dedicated volunteers, it took approximately 2,000-3,000 people hours to excavate the site and estimates at least 10,000 hours of work remain to prepare the specimen for research. “Without our volunteer team members, we wouldn’t be able to accomplish this work. We absolutely rely on them throughout the entire process,” said Irmis.

Irmis says that this new fossil find is extremely significant. Whether it is a new species or an individual of Teratophoneus, the new research will provide important context as to how this animal lived. “We’ll look at the size of this new fossil, it’s growth pattern, biology, reconstruct muscles to see how the animal moved, how fast could it run, and how it fed with its jaws. The possibilities are endless and exciting,” said Irmis.

During the past 20 years, crews from the Natural History Museum of Utah and GSENM have unearthed more than a dozen new species of dinosaurs in GSENM, with several additional species awaiting formal scientific description. Some of the finds include another tyrannosaur named Lythronax, and a variety of other, plant-eating, dinosaurs — among them duck-billed hadrosaurs, armored ankylosaurs, dome-headed pachycephalosaurs, and a number of horned dinosaurs, such as Utahceratops, Kosmoceratops, Nasutoceratops, and Machairoceratops. Other fossil discoveries include fossil plants, insect traces, snails, clams, fishes, amphibians, lizards, turtles, crocodiles, and mammals. Together, this diverse bounty of fossils is offering one of the most comprehensive glimpses into a Mesozoic ecosystem. Remarkably, virtually all of the dinosaur species found in GSENM appear to be unique to this area, and are not found anywhere else on Earth.

Dinosaur extinction and bird evolution


This American Museum of Natural History video from the USA says about itself:

18 March 2016

This spellbinding animation from the Museum’s new exhibition “Dinosaurs Among Us” traces the evolutionary transition from dinosaurs to birds.

Based on recent scientific research that examines fossils using new technologies, the transformation story unfolds as low-polygonal silhouettes of dinosaurs morph from ground-dwelling animals into flight-capable birds. The mass extinction that erased most dinosaurs 65 million years ago left a few bird lineages unscathed. Within only 15 million years all of our familiar bird groups were flourishing. These extraordinary living dinosaurs provide a vivid link to the ancient past. The Museum’s new exhibition, “Dinosaurs Among Us,” explores the continuities between living dinosaurs—birds—and their extinct ancestors, showcasing remarkable new evidence for what scientists now call one of the best-documented evolutionary transitions in the history of life.

From Cornell University in the USA:

Dino-killing asteroid’s impact on bird evolution

September 21, 2017

Human activities could change the pace of evolution, similar to what occurred 66 million years ago when a giant asteroid wiped out the dinosaurs, leaving modern birds as their only descendants. That’s one conclusion drawn by the authors of a new study published in Systematic Biology.

Cornell University Ph.D. candidate Jacob Berv and University of Bath Prize Fellow Daniel Field suggest that the meteor-induced mass extinction (a.k.a. the K-Pg event) led to an acceleration in the rate of genetic evolution among its avian survivors. These survivors may have been much smaller than their pre-extinction relatives.

“There is good evidence that size reductions after mass extinctions may have occurred in many groups of organisms,” says Berv. “All of the new evidence we have reviewed is also consistent with a Lilliput Effect affecting birds across the K-Pg mass extinction.” Paleontologists have dubbed this phenomenon the “Lilliput Effect” — a nod to the classic tale Gulliver’s Travels.

“Smaller birds tend to have faster metabolic rates and shorter generation times,” Field explains. “Our hypothesis is that these important biological characters, which affect the rate of DNA evolution, may have been influenced by the K-Pg event.”

The researchers jumped into this line of inquiry because of the long-running “rocks and clocks” debate. Different studies often report substantial discrepancies between age estimates for groups of organisms implied by the fossil record and estimates generated by molecular clocks. Molecular clocks use the rate at which DNA sequences change to estimate how long ago new species arose, assuming a relatively steady rate of genetic evolution. But if the K-Pg extinction caused avian molecular clocks to temporarily speed up, Berv and Field say this could explain at least some of the mismatch. “Size reductions across the K-Pg extinction would be predicted to do exactly that,” says Berv.

“The bottom line is that, by speeding up avian genetic evolution, the K-Pg mass extinction may have temporarily altered the rate of the avian molecular clock,” says Field. “Similar processes may have influenced the evolution of many groups across this extinction event, like plants, mammals, and other forms of life.”

The authors suggest that human activity may even be driving a similar Lilliput-like pattern in the modern world, as more and more large animals go extinct because of hunting, habitat destruction, and climate change.

“Right now, the planet’s large animals are being decimated — the big cats, elephants, rhinos, and whales,” notes Berv. “We need to start thinking about conservation not just in terms of functional biodiversity loss, but about how our actions will affect the future of evolution itself.”

The Chicxulub asteroid impact that wiped out the dinosaurs likely released far more climate-altering sulfur gas into the atmosphere than originally thought, according to new research: here.

Some herbivorous dinosaurs really omnivorous?


This 2012 video from the USA says about itself:

Maiasaura: Learn About Dinosaurs with World Book’s Professor Nick

Maiasaura was a large plant-eating dinosaur noted for its nesting behavior. Its name means good mother lizard, though dinosaurs were not lizards. Evidence suggests that its hatchlings were completely dependent on their parents for food and protection. Maiasaura lived about 75 to 80 million years ago in the area of what is now Montana. It belonged to a group known as duckbilled dinosaurs or hadrosaurids. These dinosaurs ate plants using a beak that somewhat resembled a duck’s bill.

By Carolyn Gramling, 9:00am, September 21, 2017:

Shhhh! Some plant-eating dinos snacked on crunchy critters

Crustacean shells discovered in fossilized poop reveal diet secrets of ancient herbivores

Some dinosaurs liked to cheat on their vegetarian diet.

Based on the shape of their teeth and jaws, large plant-eating dinosaurs are generally thought to have been exclusively herbivorous. But for one group of dinosaurs, roughly 75-million-year-old poop tells another story. Their fossilized droppings, or coprolites, contained tiny fragments of mollusk and other crustacean

Mollusks and crustaceans are two different groups.

shells along with an abundance of rotten wood, researchers report September 21 in Scientific Reports. Eating the crustaceans as well as the wood might have given the dinosaurs an extra dose of nutrients during breeding season to help form eggs and nourish the embryos.

“Living herd animals do occasionally turn carnivore to fulfill a particular nutritional need,” says vertebrate paleontologist Paul Barrett of the Natural History Museum in London. “Sheep and cows are known to eat carcasses or bone when they have a deficiency in a mineral such as phosphorus or calcium, or if they’re pregnant or ill.” But the discovery that some plant-eating dinos also ate crustaceans is the first example of this behavior in an extinct herbivore, says Barrett, who was not involved in the new study.

Ten years ago, paleoecologist Karen Chin of the University of Colorado Boulder described finding large pieces of rotted wood in dino dung. The coprolites were within a layer of rock in Montana, known as the Two Medicine Formation, dating to between 80 million and 74 million years ago. That layer also contained numerous fossils of Maiasaura, a type of large, herbivorous duck-billed dinosaur, or hadrosaur (SN: 8/9/14, p. 20).

Chin wondered whether the wood itself was the dino’s real dietary target. “The coprolites in Montana were associated with the nesting grounds of the Maiasaura,” she says. “I suspected that the dinosaurs were after insects in the wood. But I never found any insects in the coprolites there.”

Her hunch wasn’t too far off. Now she’s found evidence of some kind of crustaceans in dino poop. The new evidence comes from an 860-meter-thick layer of rock in Utah known as the Kaiparowits Formation, which dates to between 76.1 million and 74 million years ago. Ten of the 15 coprolites that Chin and her team examined contained tiny fragments of shell that were scattered throughout the dung. They were too small to identify by species, and may have been crabs, insects or some other type of shelled animal, Chin says. Based on the scattering of shell fragments, the animals were certainly eaten along with the wood rather than being later visitors to the dung heap.

Since bones from hadrosaurs are especially abundant in the Kaiparowits Formation, Chin suspects those kinds of dinos deposited the dung. Other large herbivores, such as three-horned ceratopsians and armored ankylosaurs, also roamed the area (SN: 6/24/17, p. 4).

The crustacean diet cheat may have been a seasonal event, related perhaps to breeding to obtain extra nutrients, Chin and colleagues say.

But how often — or why — the dinosaurs ate the shelled critters is hard to prove from the fossil dung alone, Barrett says. Herbivore coprolites are rare in the fossil record because a diet of leaves and other green plant material doesn’t leave a lot of hard material to preserve (unlike bones in carnivore dung). Coprolites with crustaceans, on the other hand, are more likely to get fossilized — and that preferential preservation might make it appear that this behavior was more frequent than it actually was. “These kinds of things give neat snapshots of specific behaviors that those animals are doing at any one time,” he adds. “But it’s difficult to build that into a bigger picture.”