Paleonews

Il blog dedicato ai Paleontologi !!!!

2009-07-17 – USA: Terizinosaur, Nothronychus graffami

Giant Clawed Dinosaur Unearthed in Utah Desert

Jennifer Viegas, Discovery News

July 14, 2009 — A multi-institutional team of scientists this week reports the discovery of a giant new dinosaur in Utah, Nothronychus graffami, which stood 13 feet tall and had nine-inch-long hand claws that looked like scythes.

SLIDE SHOW: Therizinosaur: A Dino With Nine-Inch Nails

 

Its skeleton, described in the current issue of Proceedings of the Royal Society B, represents the most complete remains ever excavated of a therizinosaur, meaning “reaper lizard.” It is one of only three such dinosaurs ever found in North America.

Lead author Lindsay Zanno told Discovery News that therizinosaurs, including the new Utah species, “are unusual in that they have small heads with a keratinous beak at the front of the mouth — the same material as the beak of modern birds — and small leaf-shaped teeth.”

“Their bellies are proportionally enormous, supporting large guts,” added Zanno, who is a researcher in the Department of Geology at The Field Museum. “They have greatly enlarged claws on their hands, short legs and tails, and four-toed feet.”

Therizinosaurs are theropod predatory dinosaurs, a group that includes the legendary Tyrannosaurus rex. The newly discovered 92.5-million-year-old Utah dinosaur was no lightweight either. As Zanno said, “You wouldn’t want to run into this guy in a dark alley.” But its teeth, beak, gut and other anatomical characteristics suggest it was an omnivore that mostly feasted on plants.

Co-author David Gillette, curator of paleontology at the Museum of Northern Arizona, told Discovery News the formidable-looking claws on Nothronychus graffami probably weren’t used to kill other large animals, but instead might have tackled “digging into termite mounds, mucking on the bottom of a lake or pond like a goose or moose, and raking leaves into its mouth from a mangrove forest like a ground sloth.”

To better understand the dietary evolution of theropods, the researchers studied information on 75 other species within this group. They determined therizinosaurs experienced an early evolutionary split from the Maniraptora, which includes modern birds and their closest extinct relatives. One such relative was Velociraptor, a carnivore that probably kicked prey to death with its large hind foot claws.

The new Utah dinosaur therefore suggests that “iconic predators like Velociraptor, one of the dinosaurian villains in the movie Jurassic Park — may have evolved from less fearsome plant-eating ancestors,” according to the scientists.

Since the very meat-loving Velociraptor emerged some 20 million years after plant-chomping Nothronychus graffami, it’s now thought that some dinosaurs might have first been carnivores that evolved into omnivores or herbivores, which re-evolved back into meat-eaters.

Paleontologists aren’t sure why some dinosaur lineages may have see-sawed back and forth with their diets.

“Our current thoughts are that in gaining the ability to eat more than just meat, maniraptorans may have been able to invade new niches in the ecosystem that were unavailable to them before,” Zanno said. “In other words, they may have been able to find a new way of living in the ecosystem and new resources to exploit that gave them an advantage and allowed them to diversify into new forms.”

Aside from what it reveals about dinosaur diets, the new Utah species is significant because of where it was found: in marine sediments that would have been between 60 and 100 miles away from the closest shoreline. The ancient sea is now part of a desert. Merle Graffam, a member of the excavation team, found the dinosaur while searching for sea-dwelling animals. The dinosaur was named after him.

“A big mystery is how this animal — either alive or as a carcass — could get so far out to sea without being torn apart by predators and scavengers,” Gillette said. “This ecosystem had at least five species of plesiosaurs and many sharks and predatory, scavenging fish.”

He added, “Maybe (the dinosaur) was stranded at sea and struggled for a few days before drowning and sinking to the bottom.”

Paul Heinrich, a research associate at the Louisiana Geological Survey, offers another explanation. He thinks such complete dinosaur skeletons recovered in seaways may have rafted out to open water on “floating islands” after storms.

The recovered Utah dinosaur’s remains are now on public display at the Museum of Northern Arizona. The exhibit, Therizinosaur: Mystery of the Sickle-Claw Dinosaur, will close in September before moving to the Arizona Museum of Natural History in Mesa.

http://dsc.discovery.com/news/2009/07/14/sickle-claw-dinosaur.html

Annunci

luglio 17, 2009 Posted by | - R. Dinosauri, - Teropodi, 1 Cretaceo, America Northern, An. Vertebrates, Mesozoic, P - Ritrovamenti fossili, Paleontology / Paleontologia | , , | Lascia un commento

2009-09-03 – Australia: 3 nuovi dinosauri (Australia, 3 new dinosaurs)

Fossili di 3 grandi dinosauri scoperti in Australia

SYDNEY (Reuters) – Fossili di tre nuove specie di dinosauri sono stati scoperti in Australia, di cui quello di un carnivoro più grande del Velociraptor dei film di Jurassic Park, lasciando intendere che l’Australia potrebbe avere un passato preistorico più complesso di quanto si pensi.

I tre fossili, due di erbivori e uno di un carnivoro — i primi resti di grandi dinosauri rinvenuti dal 1981 — sono stati trovati nel Queensland e risalgono al Cretaceo, 98 milioni di anni fa.

“Questa scoperta ci fa conoscere non solo due affascinanti giganti dal collo lungo del continente australiano antico, ma anche il nostro primo grande predatore” ha detto oggi il paleontologo John Long, del Museo Victoria.

Il paleontologo Ben Kear dell’Università La Trobe di Melbourne ha detto che la scoperta apre la strada a nuovi studi sui dinosauri australiani e il loro habitat.

“L’Australia è una delle grandi risorse poco sfruttate per la comprensione della vita nel periodo dei dinosauri”, ha detto Kear. “Questo … farà sicuramente crescere l’interesse nelle finora incomplete ma rilevanti scoperte in questo continente”.

fonte:

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Triple Fossil Find Puts Australia Back On The Dinosaur Map

ScienceDaily (July 3, 2009) — Scientists have discovered three new species of Australian dinosaur discovered in a prehistoric billabong in Western Queensland.

Artistic representations of the three new Australian dinosaur taxa: Australovenator (top); Wintonotitan (middle); Diamantinasaurus (bottom). (Credit: Artwork by: T. Tischler, Australian Age of Dinosaurs Museum of Natural History / Scott A. Hocknull, Matt A. White, Travis R. Tischler, Alex G. Cook, Naomi D. Calleja, Trish Sloan, David A. Elliott. New Mid-Cretaceous (Latest Albian) Dinosaurs from Winton, Queensland, Australia. PLoS ONE, 2009; 4 (7): e6190 DOI: 10.1371/journal.pone.0006190)

Artistic representations of the three new Australian dinosaur taxa: Australovenator (top); Wintonotitan (middle); Diamantinasaurus (bottom). (Credit: Artwork by: T. Tischler, Australian Age of Dinosaurs Museum of Natural History / Scott A. Hocknull, Matt A. White, Travis R. Tischler, Alex G. Cook, Naomi D. Calleja, Trish Sloan, David A. Elliott. New Mid-Cretaceous (Latest Albian) Dinosaurs from Winton, Queensland, Australia. PLoS ONE, 2009; 4 (7): e6190 DOI: 10.1371/journal.pone.0006190)

Reporting on July 3 in the open-access, peer-reviewed journal, PLoS ONE, Scott Hocknull and colleagues at the Queensland Museum and the Australian Age of Dinosaurs Museum of Natural History describe the fossils of three new mid-Cretaceous dinosaurs from the Winton Formation in eastern Australia: two giant, herbivorous sauropods and one carnivorous theropod, all of which are to be unveiled in Queensland on July 3. The three fossils add to our knowledge of the Australian dinosaurian record, which is crucial for the understanding of the global paleobiogeography of dinosaurian groups.

Australia’s dinosaurian fossil record is extremely poor, compared with that of other similar-sized continents, such as South America and Africa. However, the mid-Cretaceous Winton Formation in central western Queensland has, in recent years, yielded numerous fossil sites with huge potential for the discovery of new dinosaurian taxa. Between 2006 and 2009, extensive excavations have yielded many well-preserved dinosaur fossils, as well as the remains of other contemporaneous fauna.

In a single, comprehensive, publication, Hocknull and colleagues describe the remains of three individual dinosaur skeletons, found during joint Australian Age of Dinosaurs Museum and Queensland Museum digs in two different sites in the Winton Formation. They represent three new genera and species of dinosaur: two giant herbivorous sauropods and a carnivorous theropod.

The carnivore, named by the authors on the paper Australovenator wintonensis (nicknamed “Banjo”) is the most complete meat-eating dinosaur found in Australia, to date and sheds light on the ancestry of the largest-ever meat-eating dinosaurs, the carcharodontosaurs, a group of dinosaurs that became gigantic, like Giganotosaurus.

“The cheetah of his time, Banjo was light and agile,” said lead author Scott Hocknull. “He could run down most prey with ease over open ground. His most distinguishing feature was three large slashing claws on each hand. Unlike some theropods that have small arms (think T. rex), Banjo was different; his arms were a primary weapon.

“He’s Australia’s answer to Velociraptor, but many times bigger and more terrifying.”

The skeleton of Australovenator solves a 28-year-old mystery surrounding an ankle bone found in Victoria, which was originally classified as a dwarf Allosaurus, although this classification remained controversial until the discovery of Australovenator—the researchers are now able to confirm that the ankle bone belonged to the lineage that led to Australovenator.

The two plant-eating theropods, named Witonotitan wattsi (“Clancy”) and Diamantinasaurus matildae (“Matilda”), are different kinds of titanosaur (the largest type of dinosaur ever to have lived). While Witonotitan represents a tall, gracile animal, which might have fitted into a giraffe-like niche, the stocky, solid Diamantinasaurus represents a more hippo-like species.

All three dinosaurs are nicknamed after characters from a world-famous, Australian poet. Banjo Patterson composed Waltzing Matilda in 1885 in Winton, where the song was also first performed (and where the fossils were discovered). Waltzing Matilda is now considered to be Australia’s national song.

In a quirky twist of fate, the song Waltzing Matilda describes the unfortunate demise of a swag-man, who steals a jumbuck (sheep) but is driven to leap into a billabong (an Australian word for a small oxbow lake) to avoid being captured by the police. He ends up drowning in the billabong alongside the stolen sheep.

Banjo and Matilda were found buried together in what turns out to be a 98-million-year-old billabong. Whether they died together or got stuck in the mud together remains a mystery; however, echoing the song, both predator and possible prey met their end at the bottom of a billabong, 98 million years ago. This shows that processes that were working in the area over the last 98 million years are still there today. “Billabongs are a built-in part of the Australian mind,” said Hocknull, “because we associate them with mystery, ghosts and monsters.”

The finding and documentation of the fossils was a 100% Australian effort. Both Matilda and Banjo were prepared by Australian Age of Dinosaurs Museum thanks to thousands of hours of volunteer work and philanthropy.

“This is the only place in Australia where you can come off the street and be taught to be a palaeontologist and find, excavate and prepare your own part of Australian natural history,” said Hocknull. The dinosaurs will now be part of a museum collection and this effort will enable future generations of scientists to be involved in a new wave of dinosaur discoveries and to bring the general public in touch with their own natural heritage.”

This collaborative effort links closely with PLoS ONE’s philosophy of making science freely accessible to the general public. “One of my major motivations for submitting to PLoS ONE was the fact that my research will reach a much wider community, including the hundreds of volunteers and public who gave their time and money to the development of natural history collections,” said Hocknull. “They are the backbone of our work (excuse the pun) and they usually never get to see their final product because they rarely subscribe to scientific journals.”

All three new taxa, along with some fragmentary remains from other taxa, indicate a diverse Early Cretaceous sauropod and theropod fauna in Australia, and the finds will help provide a better understanding of the Australian dinosaurian record, which is, in turn, crucial for the understanding of the global palaeobiogeography of dinosaurian groups.

The authors agree that even though hundreds of bones have already been found at the site, these fossils are just the tip of the iceberg. “Many hundreds more fossils from this dig await preparation and there is much more material left to excavate,” they said. Australian Age of Dinosaurs Museum and Queensland Museum staff and volunteers will continue to dig at this and other sites in 2010.

The fossils will be unveiled at the Australian Age of Dinosaurs Museum of Natural History in Queensland, Australia, July 3 by Anna Bligh, the Premier of Queensland. Stage 1 of the museum, a non-profit, volunteer-driven, science initiative that aims to bring Australian dinosaurs to the world, will also be opened by Ms Bligh on July 3.


Journal reference:

  1. Scott A. Hocknull, Matt A. White, Travis R. Tischler, Alex G. Cook, Naomi D. Calleja, Trish Sloan, David A. Elliott. New Mid-Cretaceous (Latest Albian) Dinosaurs from Winton, Queensland, Australia. PLoS ONE, 2009; 4 (7): e6190 DOI: 10.1371/journal.pone.0006190

Source: http://www.sciencedaily.com/releases/2009/07/090703070846.htm

luglio 3, 2009 Posted by | - R. Dinosauri, - Sauropodi, - Teropodi, 1 Cretaceo, America Northern, An. Vertebrates, Articolo sc. di riferimento, FREE ACCESS, Lang. - Italiano, Mesozoic, P - Ritrovamenti fossili, Paleontology / Paleontologia | , , , , , | Lascia un commento

2009-05-20 – Montana, USA: Sentiero dei Dinosauri (Dinosaur Trail)

Dinosaur Trail (Montana): il Sentiero dei Dinosauri compie 5 anni

Ci sono voluti almeno 150 milioni d’anni ed oggi il Dinosaur Trail nel Montana, celebra il suo quinto anniversario enumerando ben 15 località archeologiche, con musei e siti paleontologici, in ben 12 comunità dell’est e del centro del Montana.

Il Montana Dinosaur Trail è un percorso adatto a famiglie con bambini e ad appassionati di paleontologia: offre la possibilità di ammirare, toccare ed imparare tutto il mondo fossile esistente nel Montana, risalente ad oltre 75 fino a 150 milioni d’anni fa.

Ogni località lungo il Dinosaur Trail dispone di mostre con fossili o repliche di dinosauri trovati nelle specifiche zone. Tra gli esemplari, anche Leonardo – un dinosauro mummia – uno dei meglio conservati al mondo, in località Malta; il Peck Rex uno scheletro intero originale del famoso T-Rex a Fort Peck; la più grande collezione di dinosauri ritrovati negli Stati Uniti, presso la località di Bozeman, ed infine le prime ossa del cucciolo di dinosauro del Nord America a Bynum e lo scheletro di Anatotitan in mostra a Ekalala.

Nel 2008 almeno 267.000 turisti hanno incluso il Dinosaur Trail nel loro viaggio nel Montana provando l’esperienza di 15 siti ben strutturati. Un terzo di questi visitatori sono internazionali. Questo a riprova che il Dinosaur Trail è veramente un’attrattiva eccezionale!

Ma la cosa ancora più intrigante è la possibilità di acquistare un Montana Dinosaur Trail Prehistoric Passport per soli 5 $, acquistabile anche direttamente nel sito www.mtdinotrail.org. Solo 2 $ il costo aggiuntivo con ordine in internet.

Le attrattive e le località del DinoTrail:
Blaine County Museum, Chinook
Carter County Museum, Ekalaka
Fort Peck Field Station of Paleontology, Fort Peck
Fort Peck Interpretive Center, Fort Peck
Garfield County Museum, Jordan
Great Plains Dinosaur Museum and Field Station, Malta
H. Earl Clack Memorial Museum, Havre
Makoshika Dinosaur Museum, Glendive
Makoshika State Park, Glendive
Museum of the Rockies, Bozeman
Old Trail Museum, Choteau
Phillips County Museum, Malta
Rudyard Depot Museum, Rudyard
Two Medicine Dinosaur Center, Bynum
Upper Musselshell Museum, Harlowton

fonte: link

maggio 20, 2009 Posted by | - R. Dinosauri, 1 Cretaceo, America Northern, An. Vertebrates, Lang. - Italiano, Mesozoic, Paleontology / Paleontologia, Places | , , , | Lascia un commento

2009-05-18 – Alberta, Canada: un nuovo dinosauro (new dinosaur)

New dino discovery – Finding sheds new light on dinosaur life in this area

Researchers believe they may have discovered yet another new dinosaur species in the South Peace.

The discovery coincides with the find of a nesting site near Grande Prairie that included the remains of infant plant-eating dinosaurs and the teeth of a predator.

Tetsuto Miyashita, a University of Alberta student from Japan, and Frederico Fanti, a paleontology graduate student from the University of Bologna, Italy, along with members of the Paleontological Society of the Peace (PSP), made the discovery that indicates dinosaurs nested further north than believed.

Miyashita said before the find, there were no significant areas between Alaska and the southern part of Alberta with a variety of dinosaurs present, and certainly none that showed dinosaurs nesting so far north.

“It established that dinosaurs were nesting at this high latitude,” he said.

“Alberta is dinosaur country, but all the dinosaurs we had previously showcased came from the southern part of the province. Now we’ve showed there is a lot of potential for the northern part as well.

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“By saying dinosaur country, now you mean the entire province, not only Drumheller and Brooks. Also this is a high-latitude locality. The dinosaurs were pushing the climatic limit in Grande Prairie.”

Though many finds have been made in southern Alberta, most of that area was under water more than 70 million years ago, which makes the possibilities in northern Alberta all that much more exciting, Fanti said.

“It was a joy to work in the Grande Prairie area verifying the significance of the fossils collected from the Wapiti (geological) Formation,” he said.

“This small northwest area was basically the only portion of Alberta and Saskatchewan that was above sea level 73 to 75 million years ago, providing habitat for land animals whose remains we collected, studied and described.”

Bert Hunt, a science professor at Grande Prairie Regional College and program co-ordinator for the PSP, said the fact dinosaurs nested this far north shows how different the climate was back in their time.

“The interesting thing is that’s the way the earth has been for most of its history. There was no cold, no poles, it was weather suitable for living,” he said. “Those animals inhabited every piece of land they could inhabit. They all had to move and eat and migrate. They ate a lot and had big bodies they had to feed, so they had to travel to find food.”

The recent discovery occurred in the well-known fossil-rich Kleskun Hills area northeast of Grande Prairie during the 2007 digging season. Fanti and Miyashita were out with Hunt, PSP president Katalin Ormay and PSP member Sheldon Graber, when Hunt spotted some fossils.

It wasn’t long before they were on their bellies looking for bones, Miyashita said.

“We found teeth, vertebrae and limb bones,” he said.

The bones belonged to freshly-hatched baby dinosaurs, about the size of guinea pigs, that would have grown to the size of elephants.

There were two types: Duckbills and some with horns.

They also discovered teeth from predators known as Troodon, small, agile carnivores that are believed to have preyed on baby dinos. Troodon was a dominant predator in the Alaska area.

Couple that with the fact that Fanti and Miyashita discovered the bones of freshwater fish and reptiles that were unlikely to have survived in the cold of Alaska, the duo believes northern Alberta was a mixture of northern and southern faunas, where animals from high and low altitudes co-existed.

This could provide some answers as to how dinosaurs responded to changing climates in their time.

This is not the first big dinosaur discovery made in northern Alberta.

Thirty-six years ago, Al Lakusta, a Montrose junior high science teacher at the time, came across a new species in a bone bed at Pipestone Creek, south of Wembley; a species that would later be named after him – pachyrhinosaurus lakustai.

Hunt said archeologists have only scratched the surface as far as the northern dinosaur remains are concerned.

“Probably in this Wapiti Formation that’s up to a kilometre thick around the Grande Prairie area, every single dinosaur, mammal or reptile will be a new species.

“We are sitting on an absolute gold mine,” he said.

“Basically Frederico, what he is doing right now (back in Italy) is bringing attention to the world that we have a layer of material and animals that have been buried and fossilized that doesn’t exist anywhere else in the world.

“Bones, skeletons and teeth that didn’t exist anywhere else, or at least we have the only fossil records.”

 

WORLD IS AWARE

The fact the discovery was made by men from Japan and Italy is significant, because it shows the world is aware of what exists here, said Hunt.

“People all over the world will be here. We have the number-four fossil site in the world and the province of Alberta makes Canada the number-four country in the world for dinosaurs,” he said.

“The world knows we have something here and it’s time we recognized we have something here, and ask ‘what are we going to do about it?’ Maybe we better gear up our efforts and our research and our digging so we have our own people. We need to have some of our own people getting the publicity and fame as well.”

Discoveries like this are really beneficial to the area when it comes to awareness and education, said PSP’s Ormay.

“If you think about the project that is in the area to build a dinosaur museum (at Pipestone Creek), if you have something that’s new, something that’s significant, something that’s exciting, that generates interest from grade school kids up to grandpas,” she said.

“It has huge potential for educational purposes or opens the door for more research. Bringing in more research and new discoveries gives basis to all this; it’s something new to sink your teeth into.”

The economic value also cannot be ignored, said Hunt.

“It’s a resource to use for tourism. 400,000 people go to the (Royal) Tyrell Museum in Drumheller. They keep that city alive,” he said.

“When people come to Alberta, they want to see the Columbia ice fields and they want to see the Drumheller dinosaur museum. To put it bluntly, it would be good for tourism.”

 

MORE TO BE DISCOVERED

There is always more to be discovered, even at the same sites, as snow and rain washes away layers of dirt and unearths new specimens every year, Hunt said.

“Every year something new is exposed,” he said.

Miyashita and Fanti, cost permitting, hope to return to the Kleskun Hills site in 2010 and continue to examine the fossils that lie buried there.

“Frederico and I have a long way to go still, but it feels good, knowing that you will walk a long way for something that you like to do,” Miyashita said.

“I know I’ve found my passion and I will go anywhere it takes me.”

 

CHRISTOPHER MILLS, Herald-Tribune staff

cmills@bowesnet.com

source: Article ID# 1570550

maggio 18, 2009 Posted by | - R. Dinosauri, America Northern, An. Vertebrates, P - Ritrovamenti fossili, Paleontology / Paleontologia | Lascia un commento

2009-05-10 – Utah, USA: ritrovata una tartaruga fossile incinta (fossil pregnant turtle)

Rare prehistoric pregnant turtle found in Utah

At least three eggs are visible from the outside of the fossil, and Montana State University researchers this week have been studying images taken from a CT scan in search of others inside.

Montana State graduate student Michael Knell says the turtle was probably about a week from laying her eggs when she died and became entombed for millions of years in sandstone.

The fossil was found in 2006 in a remote part of Grand Staircase-Escalante National Monument. The eggs weren’t discovered until after it sat in storage for two years and was being re-examined by a volunteer.

This image provided Montana State University shows CT technician, Tanya Spence preparing to run a 75 million-year-old turtle fossil through a CT scanner at Deaconess Hospital in Bozeman, Mont. (AP Photo/Montana State University, Kelly Gorham)

This image provided Montana State University shows CT technician, Tanya Spence preparing to run a 75 million-year-old turtle fossil through a CT scanner at Deaconess Hospital in Bozeman, Mont. (AP Photo/Montana State University, Kelly Gorham)

maggio 10, 2009 Posted by | - Rettili, 1 Cretaceo, America Northern, An. Vertebrates, Articolo sc. di riferimento, Mesozoic, P - Preservazione eccezionale, P - Ritrovamenti fossili, Paleontology / Paleontologia, X - Nature | , , , , , , , , , | Lascia un commento

2009-05-03 – Dinamite per liberare Dinosauri (Dynamite to reveal Dinosaurs )

Dynamite Used To Reveal New Layer Of Dinosaur Fossils ScienceDaily

What do you do when you have a fossil quarry that has yielded some of the most important and rarest of dinosaur fossils in North America, but the fossil-bearing layer of rock is tilted at 70 degrees and there is so much rock that not even jackhammers can get you to the fossils any longer?

2009-04-30-sauropod-skull 

That was the problem facing Dinosaur National Monument at a Lower Cretaceous dinosaur quarry — the one that has produced the only complete brontosaur skulls from the last 80 million years of the Age of Dinosaurs in North America. The site is so scientifically important that excavations cannot be stopped, yet there was no way to reach the bones.

Dave Larsen, Steve Bors, and Tim George, a blasting team from Rocky Mountain National Park, rode to the rescue in mid-April. Over several days these skilled employees, using their expertise with explosives, blew away the rock covering the fossils and exposed a significant amount of the fossil-bearing layer so that excavation can begin again this year. Without their talents, scientifically important fossils would have remained locked underground in their stony mausoleum.

Fossil excavation often uses small tools, either pneumatic or manual, to carefully remove rock from delicate fossils. However, in some instances, instruments that are more powerful are needed. Although explosives might seem extreme, in the right setting and in the right hands, they are the right tool for the job — staff at Dinosaur National Monument can certainly testify to that.

source: http://www.sciencedaily.com/releases/2009/04/090429131935.htm

maggio 3, 2009 Posted by | - R. Dinosauri, 1 Cretaceo, America Northern, An. Vertebrates, Mesozoic, P - Ritrovamenti fossili, Paleontology / Paleontologia | , , , | Lascia un commento

2009-05-02 – Estratte proteine da un dinosauro di 80 milioni di anni (Brachylophosaurus, Dinosaur, Proteins, soft tissue)

Proteins, soft tissue from 80-million-year-old dino support theory that molecules preserve over time

A North Carolina State University paleontologist has more evidence that soft tissues and original proteins can be preserved over time – even in fossilized remains – in the form of new protein sequence data from an 80 million-year-old hadrosaur, or duck-billed dinosaur.

Dr. Mary Schweitzer, associate professor of marine, earth and atmospheric sciences at NC State with a joint appointment at the N.C. Museum of Natural History, along with colleague Dr. John Asara from the Beth Israel Deaconess Medical Center (BIDMC) and Harvard Medical School, Dr. Chris Organ from Harvard University, and a team of researchers from Montana State University, the Dana Farber Cancer Institute, and Matrix Science Ltd. analyzed the hadrosaur samples.

The researchers’ findings appear in the May 1 edition of Science.

Schweitzer and Asara had previously used multiple methods to analyze soft tissue recovered from a 68 million-year-old Tyrannosaurus Rex. Mass spectrometry conducted on extracts of T. rex bone supported their theory that the materials were original proteins from the dinosaur.

These papers were controversial, and the team wanted to demonstrate that molecular preservation of this sort in dinosaurs was not an isolated event. Based upon other studies, they made predictions of the type of environment most likely to favor this preservation, so Schweitzer and students, working with Jack Horner’s Museum of the Rockies field crews, went looking for a dinosaur preserved under a lot of sandstone. Using specially designed field methodology, with the aim of avoiding environmental exposure until the fossil was inside the lab, they set aside the femur from a Brachylophosaurus canadensis – a hadrosaurid dinosaur–buried deeply in sandstone in the Judith River formation.

“This particular sample was chosen for study because it met our criteria for burial conditions of rapid burial in deep sandstones,” Schweitzer says. “We know the moment the fossil is removed from chemical equilibrium, any organic remains immediately become susceptible to degradation. The more quickly we can get it from the ground to a test tube, the better chance we have of recovering original tissues and molecules.”

Preliminary results seemed to confirm their methodology, as Schweitzer found evidence of the same fibrous matrix, transparent, flexible vessels and preserved microstructures she had seen in the T. rex sample in the much older hadrosaur bone. Because of the rapidity of analyses after the bones were removed, the preservation of these dinosaurian components was even better. The samples were examined microscopically via both transmitted light and electron microscopes to confirm that they were consistent in appearance with collagen. They were also tested against antibodies that are known to react with collagen and other proteins.

Next, Schweitzer sent the samples to Asara’s lab to be analyzed by a new mass spectrometer, capable of producing sequences with much greater resolution than the one used previously. Mass spectrometry identifies molecules by measuring the mass of the protein fragments, or peptides, that result from breaking apart molecules with specific enzymes. The masses are measured with very high mass accuracy, and then compared with existing databases of proteins to achieve a best fit. In this way, Asara was able to identify eight collagen peptides from the hadrosaur, then confirm the identity of the sequences by comparing them both to synthesized fragments and to modern proteins analyzed under the same conditions. Once sequence data were validated, they were evaluated by Organ who determined that, like T.rex, this dinosaur’s protein family tree is closer to that of modern birds than that of alligators.

All results were independently verified by researchers at BIDMC, Montana State University, Harvard University, the Dana Farber Cancer Institute, and Matrix Science of London.

The data were consistent with that of the earlier T. rex analysis, confirming that molecular preservation in fossilized remains is not an isolated event. “We used improved methodology with better instrumentation, did more experiments and had the results verified by other independent labs,” Schweitzer says. “These data not only build upon what we got from the T. rex, they take the research even further.”

Schweitzer hopes that this finding will lead to more work by other scientists on these ancient molecules.

“I’m hoping in the future we can use this work as a jumping off point to look for other proteins that are more species-specific than collagen. It will give us much clearer insight into all sorts of evolutionary questions.”

Contact: Tracey Peake – tracey_peake@ncsu.edu – 919-515-6142 – North Carolina State University###

 source: eurekalert

———————–

An abstract of the paper follows.

“Biomolecular Characterization and Protein Sequences of the Campanian Hadrosaur Brachylophosaurus canadensis
Authors: Mary H. Schweitzer, North Carolina State University and the N.C. Museum of Natural Sciences; John M. Asara, Beth Israel Deaconess Medical Center and Harvard Medical School, et al.
Published: May 1, 2009 in Science

Abstract: Molecular preservation in non-avian dinosaurs is controversial. We present multiple lines of evidence that endogenous proteinaceous material is preserved in bone fragments and soft tissues from an 80 million year old Campanian hadrosaur, Brachylophosaurus canadensis (MOR 2598). Microstructural and immunological data are consistent with preservation of multiple bone matrix and vessel proteins, and phylogenetic analyses of Brachylophosaur collagen sequenced by mass spectrometry robustly support the bird-dinosaur clade, consistent with an endogenous source for these collagen peptides. These data complement earlier results from Tyrannosaurus rex (MOR 1125) and confirm that molecular preservation in Cretaceous dinosaurs is not a unique event.

maggio 2, 2009 Posted by | - Ornitopodi, - R. Dinosauri, 1 Cretaceo, America Northern, An. Vertebrates, Articolo sc. di riferimento, Bl - Top posts, Mesozoic, P - Preservazione eccezionale, Paleontology / Paleontologia, X - Science | , , , , , | Lascia un commento

2009-04-23 – Puijila darwini: Anello mancante nell`evoluzione dei Pinnipedi (missing link in pinniped evolution)

recommended links:

http://nature.ca/puijila/index_e.cfm (Official home page)

http://www.eurekalert.org/pub_releases/2009-04/cmon-feo042009.php (good scientific description of the discovery)

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 Fossil of a walking seal found

Remains of a previously unknown mammal could represent a missing link in pinniped evolution
Web edition : Wednesday, April 22nd, 2009 
Researchers discovered remains of a previously unknown pinniped in the Canadian Arctic. (Inset shows bones that were found.) The fossilized skeleton was about 65 percent complete. (Illustration fills in the missing pieces.)
Researchers discovered remains of a previously unknown pinniped in the Canadian Arctic. (Inset shows bones that were found.) The fossilized skeleton was about 65 percent complete. (Illustration fills in the missing pieces.)

A fossilized skeleton of what researchers are calling a walking seal has been uncovered in the Canadian Arctic. The remains of this previously unknown mammal could shed light on the evolution of pinnipeds, the group that includes seals, sea lions and walruses, researchers report in the April 23 Nature.

The animal, named Puijila darwini, had a long tail and an otterlike body with webbed feet and legs like a terrestrial animal, the researchers report. But P. darwini also had a pinniped-like skull.

“We realized there was no way this was an otter,” says study coauthor Natalia Rybczynski of the Canadian Museum of Nature in Ottawa. The walking seal probably lived about 20 million years ago and was adept at moving both on land and in water, the team reports. 

 
Researchers describe Puijila darwini (illustration shown) as a walking seal, with the legs of a terrestrial animal, a seal-like skull and webbed feet.

Researchers describe Puijila darwini (illustration shown) as a walking seal, with the legs of a terrestrial animal, a seal-like skull and webbed feet.

 Scientists had theorized that pinnipeds evolved from land-dwelling ancestors but had little fossil evidence to support that claim. The new finding could be the missing link in pinniped evolution, the researchers report.

“This is a fantastic discovery,” comments evolutionary biologist Annalisa Berta of San Diego State University.

The finding may also indicate that the Arctic was a geographic center for pinniped evolution, the researchers speculate.

But, Berta notes, other early pinnipeds have been discovered in the North Pacific and Eurasia. “We can’t yet conclude the Arctic was the area of origin for pinnipeds,” Berta says.

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Otter-like fossil reveals early seal evolution

The Associated Press – ‎22-apr-2009‎
One expert called it “a fantastic discovery” that fills a crucial gap in the fossil record. The 23 million-year-old creature was not a direct ancestor of

aprile 23, 2009 Posted by | - Mammiferi, America Northern, An. Vertebrates, Articolo sc. di riferimento, P - Evoluzione, P - morfologia funzionale, P - Ritrovamenti fossili, Paleontology / Paleontologia, X - Nature | , , , , , , , , , , | Lascia un commento

2009-04-16 – Philadelphia, USA: Hadrosaurus foulkii, America’s “first dinosaur” on display

America’s “first dinosaur” on display in Philadelphia until May 3


Hadrosaurus by Joseph Smit (1836-1929) from Nebula
to Man, 1905 England
http://www.copyrightexpired.com/earlyimage/prehistoriclifebeforekt/

Hadrosaurus foulkii doesn’t have the name recognition of a Tyrannosaurus rex, but this dinosaur made a profound impact on our view of dinosaurs today. Hadrosaurus is a hometown hero with literally deep roots in the Philadelphia area. Discovered in nearby Haddonfield New Jersey and first displayed at the Academy of Natural Sciences in Philadelphia, Hadrosaurus foulkii led the migration of dinosaurs out of the ground, on display in museums, and into our imaginations.

Prior to the Civil War, little was known about the dinosaurs. In the summer of 1858, Philadelphia lawyer William Parker Foulke vacationed in Haddonfield New Jersey. While searching for fossils, Foulke discovered a collection of gigantic bones.

Foulke brought these bones to the Academy of Natural Sciences in Philadelphia, where they were examined by museum curator Joseph Leidy. As a professor of anatomy, Leidy recognized that the bones came from an unknown creature. At this time, the only evidence of dinosaurs came from a mismatched collection of bones and teeth.

The collection of bones discovered in Haddonfield New Jersey represented the most complete dinosaur skeleton of the time. Leidy named the newly discovered dinosaur, Hadrosaurus foulkii. The genus Hadrosaurus means “bulky lizard.”The species name foulkii was provided to honor William Parker Foulke.

10 years later, New York artist Benjamin Waterhouse Hawkins assembled the bones into a mounted skeleton for the Academy. The completed skeleton debuted in November 1868, the first display of its kind. Today dinosaur skeletons are key attractions at natural history museums around the world.

The discovery of thousands of dinosaur fossils in the time since Hadrosaurus was first found on a farm in New Jersey, contributes to a more accurate representation of the dinosaur that was possible in 1868. You can view the reconstruction of Hadrosaurus foulkii on display at the Academy of Natural Sciences in Philadelphia until May 3, 2009.

aprile 16, 2009 Posted by | - R. Dinosauri, America Northern, An. Vertebrates, Mostre & Fiere, Musei, Paleontology / Paleontologia, Places | , , , , , | Lascia un commento

2009-03-19 – Tianyulong confuciusi: un nuovo dinosauro con le piume (feathered Ornithopd Dinosaur)

Un nuovo dinosauro con le piume

Scoperto in Cina un fossile risalente a più di 100 milioni di anni fa

 Il ritrovamento in Cina di un nuovo fossile di dinosauro dotato di piumaggio riapre il dibattito sulla diffusione di questi rettili preistorici. Questa volta gli scienziati hanno portato alla luce un piccolo esemplare che viveva nelle regioni nord-orientali del continente asiatico più di cento milioni di anni fa. L’animale aveva il corpo coperto da lunghi filamenti simili a piume, era piccolo, agile e scattante. Camminava su due zampe, aveva una lunga coda e si cibava probabilmente di piante, insetti e piccoli vertebrati.

PENNUTI PREISTORICI – È stato chiamato Tianyulong confuciusi, dalla somma del nome del museo dove è conservato e di quello del filosofo Confucio. Diversamente dai dinosauri «piumati» ritrovati fino ad oggi e appartenenti al sottordine dei teropodi (di cui fa parte anche il T-rex), questo pennuto preistorico è un eterodontosauride vissuto nel Cretaceo inferiore, circa 144 milioni di anni fa. Secondo gli scienziati le sue piume sono diverse sia da quelle degli uccelli che da quelle dei cugini teropodi: si tratta infatti di strutture meno flessibili e più compatte, e comunque non adatte al volo. Ma nonostante le differenze, sicuramente tutte le tipologie di proto-piume conosciute sono correlate tra loro.

  L’ETÀ DELLE PIUME – Secondo alcuni paleontologi quindi le piume primitive sono una caratteristica ereditata dai due gruppi di dinosauri da un antenato comune e risalgono presumibilmente a 200 milioni di anni fa. Grazie alle particolari condizioni geologiche della provincia cinese del Liaoning, è sempre più frequente il ritrovamento di fossili di dinosauri provvisti di piume, e ciò fa pensare che fossero molto più diffusi di quanto si pensasse fino a pochi anni fa. Resta comunque ancora oscura la funzione (probabilmente ornamentale) di queste appendici che, come le piume degli uccelli attuali, erano molto colorate ma sicuramente alle origini non erano nate per volare

Valentina Tubino
19 marzo 2009

fonte: corriere.it

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Reconstruction of Tianyulong confuciusi, a feathered heterodontosaurid ornithischian dinosaur (Illustration: Li-Da Xing)
Reconstruction of Tianyulong confuciusi, a feathered heterodontosaurid ornithischian dinosaur (Illustration: Li-Da Xing)

Approfondimento sui Blog

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 An Early Cretaceous heterodontosaurid dinosaur with filamentous integumentary structures

Xiao-Ting Zheng, Hai-Lu You, Xing Xu & Zhi-Ming Dong

Nature 458, 333-336 (19 March 2009) | doi:10.1038/nature07856

Ornithischia is one of the two major groups of dinosaurs, with heterodontosauridae as one of its major clades. Heterodontosauridae is characterized by small, gracile bodies and a problematic phylogenetic position1, 2. Recent phylogenetic work indicates that it represents the most basal group of all well-known ornithischians3. Previous heterodontosaurid records are mainly from the Early Jurassic period (205–190 million years ago) of Africa1, 3. Here we report a new heterodontosaurid, Tianyulong confuciusi gen. et sp. nov., from the Early Cretaceous period (144–99 million years ago) of western Liaoning Province, China. Tianyulong extends the geographical distribution of heterodontosaurids to Asia and confirms the clade’s previously questionable temporal range extension into the Early Cretaceous period. More surprisingly, Tianyulong bears long, singular and unbranched filamentous integumentary (outer skin) structures. This represents the first confirmed report, to our knowledge, of filamentous integumentary structures in an ornithischian dinosaur.

Correspondence to: Hai-Lu You: Email: youhailu@gmail.com).

·         abstract and links

·         Figures and tables

·         Supplementary info

marzo 19, 2009 Posted by | - Ornitopodi, - R. Dinosauri, 1 Cretaceo, America Northern, An. Vertebrates, Articolo sc. di riferimento, Bl - Top posts, Blogs, Lang. - Italiano, Mesozoic, P - Evoluzione, P - morfologia funzionale, P - Paleoetologia, P - Preservazione eccezionale, Paleontology / Paleontologia, SVPOW, Theropoda, X - Nature | , , , | Lascia un commento