Paleonews

Il blog dedicato ai Paleontologi !!!!

2009-07-13 – New Theropod: Kemkemia auditorei (Cau & Maganuco, 2009)

Congratuazioni agli autori !!!

Ecco i post sul blog Theropda (A.Cau):

Annunci

luglio 13, 2009 Posted by | - R. Dinosauri, - Teropodi, 1 Cretaceo, Africa, An. Vertebrates, Articolo sc. di riferimento, Blogs, Lang. - Italiano, P - Ritrovamenti fossili, Paleontology / Paleontologia, Theropoda | , , , , , | Lascia un commento

2009-07-06 – La masticazione degli Adrosauri (chewing of Adrosaurs)

Lo studio al microscopio elettronico delle tracce sui denti di alcuni Adrosauri ne rivelano la complessa tipologia di masticazione.

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Dino tooth sheds new light on ancient riddle

Scientists discover major group of dinosaurs had unique way of eating unlike anything alive today

IMAGE: These are teeth from the lower jaw of a hadrosaur, Edmontosaurus, showing its multiple rows of leaf-shaped teeth. The worn, chewing surface of the teeth is towards the top.Click here for more information. 

Microscopic analysis of scratches on dinosaur teeth has helped scientists unravel an ancient riddle of what a major group of dinosaurs ate- and exactly how they did it!

Now for the first time, a study led by the University of Leicester, has found evidence that the duck-billed dinosaurs- the Hadrosaurs- in fact had a unique way of eating, unlike any living creature today.

Working with researchers from the Natural History Museum, the study uses a new approach to analyse the feeding mechanisms of dinosaurs and understand their place in the ecosystems of tens of millions of years ago. The results are published today in the Proceedings of the National Academy of Sciences.

Palaeontologist Mark Purnell of the University of Leicester Department of Geology, who led the research, said: “For millions of years, until their extinction at the end of the Cretaceous, duck-billed dinosaurs – or hadrosaurs – were the World’s dominant herbivores. They must have been able to break down their food somehow, but without the complex jaw joint of mammals they would not have been able to chew in the same way, and it is difficult to work out how they ate. It is also unclear what they ate: they might have been grazers, cropping vegetation close to the ground – like today’s cows and sheep – or browsers, eating leaves and twigs – more like deer or giraffes. Not knowing the answers to these questions makes it difficult to understand Late Cretaceous ecosystems and how they were affected during the major extinction event 65 million years ago.

IMAGE: These are teeth from the upper jaw of a hadrosaur, Edmontosaurus. The specimen was molded and coated with gold for examination using a Scanning Electron Microscope to give high power…Click here for more information. 

Our study uses a new approach based on analysis of the microscopic scratches that formed on hadrosaur’s teeth as they fed, tens of millions of years ago. The scratches have been preserved intact since the animals died. They can tell us precisely how hadrosaur jaws moved, and the kind of food these huge herbivores ate, but nobody has tried to analyse them before.”

The researchers say that the scratches reveal that the movements of hadrosaur teeth were complex and involved up and down, sideways and front to back motion. According to Paul Barrett palaeontologist at the Natural History Museum “this shows that hadrosaurs did chew, but in a completely different way to anything alive today. Rather than a flexible lower jaw joint, they had a hinge between the upper jaws and the rest of the skull. As they bit down on their food the upper jaws were forced outwards, flexing along this hinge so that the tooth surfaces slid sideways across each other, grinding and shredding food in the process”.

The scratch patterns provide confirmation of a theory of hadrosaur chewing first proposed 25 years ago, and provides new insights into their ecology, say the researchers.

The research also sheds light on what the dinosaurs ate. Vince Williams of the University of Leicester said: “Although the first grasses had evolved by the Late Cretaceous they were not common and it is most unlikely that grasses formed a major component of hadrosaur diets. We can tell from the scratches that the hadrosaur’s food either contained small particles of grit, normal for vegetation cropped close to the ground, or, like grass, contained microscopic granules of silica. We know that horsetails were a common plant at the time and have this characteristic; they may well have been an important food for hadrosaurs”.

IMAGE: This is a highly magnified Scanning Electron Microscope view of the surface of one of the hadrosaur teeth, showing the scratches created about 67 million years ago by tooth movements…Click here for more information. 

One of the big surprises of this study is that so much information about such large animals can be gleaned from such a tiny patch of tooth. “By looking at the pattern of scratches in an area that is only about as wide as a couple of human hairs we can work out how and what these huge herbivores were eating” notes Williams. “And because we can analyse single teeth, rather than whole skeletons, the technique has the potential to tell us a lot more about dinosaur feeding and the ecosystems in which they lived.”

 

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For interviews contact:
Dr Mark A. Purnell
Reader in Geology
Department of Geology
University of Leicester
University Road
Leicester LE1 7RH
UK
Tel +44 116 252 3645
Fax +44 116 252 3918
http://www.le.ac.uk/people/map2

1. The erroneous idea that all dinosaurs could chew is so widely accepted that the memorable ‘Chewits’ advertising campaigns of the 1980s were based on the idea. Note that the dinosaur shown in the adverts is not a hadrosaur:
http://www.youtube.com/watch?v=NJUwQIXPCBE
http://www.youtube.com/watch?v=420UecB2YZQ

2. The paper “Quantitative analysis of dental microwear in hadrosaurid dinosaurs, and the implications for hypotheses of jaw mechanics and feeding” by Vincent S. Williams, Paul M. Barrett and Mark A. Purnell is published in the Proceedings of the National Academy of Sciences (online Early Edition).

3. Vince Williams and Mark Purnell are at the University of Leicester, UK; Paul Barrett is at the Natural History Museum, London, UK. A pdf of the paper is available from Mark Purnell: map2@le.ac.uk

4. Winner of Visit London’s 2008 Kids Love London Best Family Fun Award, the Natural History Museum is also a world-leading science research centre. Through its collections and scientific expertise, the Museum is helping to conserve the extraordinary richness and diversity of the natural world with groundbreaking projects in 68 countries

5. To arrange an interview with Paul Barrett please contact: Claire Gilby, Senior Press Officer, Natural History Museum, Tel: 020 7942 5106 Email: c.gilby@nhm.ac.uk (not for publication)

6. Following images can be obtained from University of Leicester pressoffice@le.ac.uk

Captions follow:

     

  • Teeth from the lower jaw of a hadrosaur, Edmontosaurus, showing its multiple rows of leaf-shaped teeth. The worn, chewing surface of the teeth is towards the top. Credit: Vince Williams, University of Leicester.
  • Teeth from the upper jaw of a hadrosaur, Edmontosaurus. The specimen was moulded and coated with gold for examination using a Scanning Electron Microscope to give high power magnification of the microscopic scratches. Credit: Vince Williams, University of Leicester.
  • Highly magnified Scanning Electron Microscope view of the surface of one of the hadrosaur teeth, showing the scratches created about 67 million years ago by tooth movements and feeding. The small black boxes show the areas, each less than half a millimetre wide, in which scratches were analysed. Credit: Vince Williams, University of Leicester.
  • Artists reconstruction of a hadrosaur eating; analysis of tooth wear indicates grazing low growing silica rich plants, like horsetails, was more likely than browsing on bushes. Contact c.gilby@nhm.ac.uk for image.

Hadrosaur fact file
This study is based on Edmontosaurus: Lived USA and Canada 65-68 million years ago; Length up to 13 m, weight up to 3 tonnes; One of the most abundant dinosaurs of its time; Known from many complete skeletons, including several mummies with skin impressions and gut contents preserved.

 Notes for editors:

luglio 6, 2009 Posted by | - Adrosauri, - Ornitopodi, - R. Dinosauri, An. Vertebrates, Articolo sc. di riferimento, Italiano (riassunto), P - morfologia funzionale, Paleontology / Paleontologia, X - PNAS | , , , | 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

2009-07-02 – Germania: Flauto preistorico (Germany, Prehistoric Flute)

GERMANIA: TROVATO UN FLAUTO PREISTORICO DI 35. 000 ANNI

(AGI) – Parigi, 24 giu. – La Germania si sta rivelando una miniera di reperti preistorici. Un flauto risalente a 35.000 anni fa e’ stato ritrovato vicino Ulm nella valle di Ach, nel Sud del Paese nello stesso sito dove e’ stata rinvenuta la cosiddetta ‘Venere di Hohle Fels’ una statuina di avorio raffigurante una donna appena abbozzata. La scoperta’ e’ frutto del lavoro di un’equipe di archeologi guidati da Nicholas Conard. Secondo quanto riferisce Nature il flauto, realizzato con un osso di avvoltoio ha cinque buchi, e’ lungo 22 centimetri e si puo’ suonare come uno strumento attuale.

fonte: http://www.agi.it/estero/notizie/200906242311-est-rt11367-germania_trovato_un_flauto_preistorico_di_35_000_anni

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Prehistoric flute in Germany is oldest known

June 24th, 2009

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–>Prehistoric flute in Germany is oldest knownEnlargeThe flute. Foto: H. Jensen. Copyright: Universität Tübingen.

Excavations in the summer of 2008 at the sites of Hohle Fels and Vogelherd produced new evidence for Paleolithic music in the form of the remains of one nearly complete bone flute and isolated small fragments of three ivory flutes.

 

 

 

 

 

The most significant of these finds, a nearly complete bone flute, was recovered in the basal Aurignacian deposits at Hohle Fels Cave in the Ach Valley, 20 km west of Ulm. The flute was found in 12 pieces. The fragments were distributed over a vertical distance of 3 cm over a horizontal area of about 10 x 20 cm. This flute is by far the most complete of all of the musical instruments thus far recovered from the caves of Swabia.

The preserved portion of the bone flute from Hohle Fels has a length of 21.8 cm and a diameter of about 8 mm. The flute preserves five finger holes. The surfaces of the flute and the structure of the bone are in excellent condition and reveal many details about the manufacture of the flute. The maker carved two deep, V-shaped notches into one end of the instrument, presumably to form the proximal end of the flute into which the musician blew. The find density in this stratum is moderately high with much flint knapping debris, worked bone and ivory, bones of horse, reindeer, mammoth, cave bear, ibex, as well as burnt bone. No diagnostic human bones have been found in deposits of the Swabian Aurignacian, but we assume that modern humans produced the artifacts from the basal Aurignacian deposits shortly after their arrival in the region following a migration up the Danube Corridor.

The maker of the flute carved the instrument from the radius of a griffon vulture (Gyps fulvus). This species has a wingspan between 230 and 265 cm and provides bones ideal for large flutes. Griffon vultures and other vultures are documented in the Upper Paleolithic sediments of the Swabian caves.

The 2008 excavations at Hohle Fels also recovered two small fragments of what are almost certainly two ivory flutes from the basal Aurignacian. The different dimensions of the fragments indicate that the two finds are not from the same instrument. Excavators at Vogelherd in the Lone Valley 25 km northwest of Ulm recovered another isolated fragment of another ivory flute.

The technology for making an ivory flute is much more complicated than making a flute from a bird bone. This process requires forming the rough shape along the long axis of a naturally curved piece of ivory, splitting it open along one of the bedding plains in the ivory, carefully hollowing out the halves, carving the holes, and then rejoining the halves of the flute with an air-tight seal. Given the tendency of delicate ivory artifacts to break into many pieces, it is not unusual to find isolated pieces of such artifacts.

The 10 radiocarbon dates from the basal Aurignacian fall between 31 and 40 ka BP. Available calibrations and independent controls using other methods indicate that the flutes from Hohle Fels predate 35,000 calendar years ago. Apart from the caves of the Swabian Jura there is no convincing evidence for musical instruments predating 30 ka BP.

These finds demonstrate that music played an important role in Aurignacian life in the Ach and Lone valleys of southwestern Germany. Most of these flutes are from archaeological contexts containing an abundance of organic and lithic artifacts, hunted fauna, and burnt bone. This evidence suggests that the inhabitants of the sites played musical instruments in diverse social and cultural contexts and that flutes were discarded with many other forms of occupational debris. In the case of Hohle Fels, the location of the bone flute in a thin archaeological horizon only 70 cm away from a female figurine of similar age suggests that a possible contextual link exists between these two finds.

The flutes from Hohle Fels, Vogelherd and previous finds from nearby Geißenklösterle Cave demonstrate that a musical tradition existed in the cultural repertoire of the Aurignacian around the time modern humans settled in the Upper Danube region. The development of a musical tradition in the Aurignacian accompanied the development of the early figurative art and numerous innovations, including a wide array of new forms of personal ornaments, as well as new lithic and organic technologies. The presence of music in the lives of Upper Paleolithic peoples did not directly produce a more effective subsistence economy and greater reproductive success, but music seems to have contributed to improved social cohesion and new forms of communication, which indirectly contributed to demographic expansion of modern humans relative to the culturally more conservative Neanderthal populations.

The flutes from the caves of the Swabian Jura constitute a key part a major exhibit in Stuttgart entitled Ice Age Art and Culture, which will run from September 18, 2009 – January 10, 2010.

More information: The authors of the paper “New flutes document the earliest musical tradition in southwestern Germany” are Nicholas J. Conard Maria Malina and Susanne C. Münzel. The paper will be published as Advance online publication in Nature, June 25, 2009.

Provided by Universitaet Tuebingen

source: http://www.physorg.com/news165069257.html

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luglio 2, 2009 Posted by | Archeology / Archeologia, Articolo sc. di riferimento, Cenozoic, Europa, Lang. - Italiano, P - Paleoantropologia, P - Ritrovamenti fossili, Paleontology / Paleontologia, X - Nature | , , , , , | 1 commento

2009-06-19 – Mongolia: Nuovo Psittacosauro (new Psittacosaur)

Parrot-like dinosaur found in Mongolia

A new dinosaur resembling a giant parrot has been discovered in Mongolia.

 By Chris Irvine
Published: 7:00AM BST 17 Jun 2009
New dinosaur, Psittacosaurus gobiensis: Parrot-like dinosaur found in Mongolia
A new dinosaur, named Psittacosaurus gobiensis, meaning ‘parrot dinosaur’ has been discovered in Mongolia

The creature, Psittacosaurus gobiensis whose name means “parrot lizard”, is thought to have lived about 110 million years ago.

Psittacosaurs are noted for being the most species-rich dinosaur genus with at least nine different species, including the latest found in the Gobi Desert, a famous dinosaur graveyard.

Features of the dinosaur included a near perfect skull, strong jaw muscles and a powerful biting and crushing bill – showing that it evolved structures like those in today’s parrots.

The three feet long psittacosaurs may also have had a diet dominated by nuts and seeds, owing to the presence of many large stomach stones, according to the findings published in Proceedings of the Royal Society B: Biological Sciences.

Prof Paul Sereno, a Biologist from the University of Chicago, said analysis of its skull showed it chewed its food in a similar way to modern parrots.

“These and other features, along with the presence of numerous large stomach stones, suggest that psittacosaurs may have had a high-fibre, nut eating diet,” he said.

Its short snout just a third of the skull length was different to most dinosaurs, giving the skull its parrot-esque profile.

They ate nothing but plants and walked normally on two legs but could reach the ground with their three-fingered hands.

They were good runners and were extremely successful in Asia about 100 million years ago, during the Cretaceous Period.

“Psittacosaurs are all relatively small in body size, ranging from one to two metres in body length. Their geographic range is limited to central Asia, and their temporal range may be as narrow as 10-20 million years in the mid Cretaceous,” said Prof Sereno.

It is a member of the Ceratopsia group of herbivorous, beaked dinosaurs, which also include the more famous Triceratops.

source: telegraph.co.uk

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Other links: click here

giugno 19, 2009 Posted by | 1 Cretaceo, Articolo sc. di riferimento, Asia, Mesozoic, P - Preservazione eccezionale, P - Ritrovamenti fossili | , , , , | Lascia un commento

2009-06-18 – Limusaurus inextricabilis and the evolution of dinosaurs hands

per informazioni in italiano vedi:

BLOG THEROPODA – Limusaurus inextricabilis Xu et al. (2009) – Prima Parte: Un Ceratosauria senza denti dal Giurassico Superiore della Cina!

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New dinosaur gives bird wing clue

Limusarus fossil (James Clark)
The Limusaurus fossil sits among small crocodile fossils

A new dinosaur unearthed in western China has shed light on the evolution from dinosaur hands to the wing bones in today’s birds.

The fossil, from about 160 million years ago, has been named Limusaurus inextricabilis.

The find contributes to a debate over how an ancestral hand with five digits evolved to one with three in birds.

The work, published in Nature, suggests that the middle three digits, rather than the “thumb” and first two, remain.

Theropods – the group of dinosaurs ancestral to modern birds and which include the fearsome Tyrannosaurus rex – are known for having hands and feet with just three digits.

It’s a really weird animal – it’s got no teeth, had a beak and a very long neck, and very wimpy forelimbs
James Clark, GWU

It has been a matter of debate how the three-fingered hand developed from its five-fingered ancestor. Each digit among the five was composed of a specific number of bones, or phalanges.

Palaeontologists have long argued that it is the first (corresponding to the thumb), second, and third fingers from that ancestral hand that survived through to modern birds, on grounds that the three fingers in later animals exhibit the correct number of phalanges.

However, developmental biologists have shown that bird embryos show growth of all five digits, but it is the first and fifth that later stop growing and are reabsorbed.

The remaining three bones fuse and form a vestigial “hand” hidden in the middle of a bird’s wing.

‘Weird animal’

James Clark of George Washington University in Washington DC and Xing Xu from the Institute of Vertebrate Paleontology and Paleoanthropology in Beijing hit an palaeontologist’s gold mine in the Junggar Basin of northwestern China.

Previous digs have unearthed the oldest known fossil belonging to the tyrannosaur group and the oldest horned dinosaur among several others.

Limusarus fossil (Portia Sloan)
The dinosaurs had beaks and may have had feathers

This time, the ancient mire has yielded a primitive ceratosaur, a theropod that often had horns or crests, many of whom had knobbly fingers without claws.

“It’s a really weird animal – it’s got no teeth, had a beak and a very long neck, and very wimpy forelimbs,” Professor Clark told BBC News.

“Then when we looked closely at the hand, we noticed it was relevant to a very big question in palaeontology.”

The fossil has a first finger which is barely present, made up of just one small bone near the wrist. The fifth finger is gone altogether.

It is a fossil that appears to offer a snapshot of evolution, proving that the more modern three-fingered hand is made up of the middle digits of the ancestral hand, with the outer two being shed.

The third finger is made up of the four phalange bones that the second should have, and it is presumed that the second would lose one bone to become like the first finger that was missing in the fossil.

This process of shifting patterns of gene expression from one limb or digit to another is known as an “identity shift”, and was again caught in the act – making the conflicting theories of bird hand origin suddenly align.

“This is amazing – it’s the first time we’ve seen this thing actually starting to disappear,” Jack Conrad, a palaeontologist at the American Museum of Natural History, told BBC News.

“There’s been this fundamental rift – there was no way to make peace between the good data we were seeing from the developmental biologists and the palaeontological evidence that showed with every fossil we found we were seeing [fingers] one, two and three.”

from: http://news.bbc.co.uk/1/hi/sci/tech/8105513.stm

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Other links:

Fossil Solves Mystery of Dinosaur Finger Evolution

FOXNews – ‎17/giu/2009‎

By Jeanna Bryner Bird wings clearly share ancestry with dinosaur “hands” or forelimbs. A school kid can see it in the bones.

Fossil Catches Dinosaur Red-Handed, Evolving Into Bird Wired News

NEW DINOSAUR: Fossil Fingers Solve Bird Wing Mystery? National Geographic

giugno 18, 2009 Posted by | - R. Dinosauri, - Teropodi, An. Vertebrates, Articolo sc. di riferimento, Asia, Italiano (riassunto), P - Evoluzione, P - Ritrovamenti fossili, Paleontology / Paleontologia, X - Nature | , | 1 commento

2009-06-12 – Italia: il 4 dinosauro !!! (fourth Italian dinosaur)

Con un po` di ritardo ecco il post su una notizia “eccezonale”.

Un osso ritrovato in sedimenti di origine marina nel Cenomaniano della Sicilia e stato identificato come appartenente a un dinosauro (il quarto ritovato in Italia).

Per info piu` dettagliate: Blog – Teropoda

Riferimento bibliografico:

Garilli, V, et al. “First dinosaur bone from Sicily identified by histology and its palaeobiogeographical implications.” Neues Jahrbuch für Geologie und Paläontologie 252.2 (2009):207-216.

giugno 12, 2009 Posted by | - Italia, - R. Dinosauri, An. Vertebrates, Articolo sc. di riferimento, Bl - Top posts, Blogs, Europa, Lang. - Italiano, P - Ritrovamenti fossili, Paleontology / Paleontologia, Theropoda | , , , , , | Lascia un commento

2009-06-03 – Anoiapithecus brevirostris “Lluc”: new Hominid (nuovo ominide scoperto in Spagna)

In Italiano:

Lluc è il nome dell’ “Anoiapithecus” possibile nuovo antenato dell  – Soverato News – ‎2-giu-2009‎ – Non è detto però che l’ Anoiapithecus (nome scientifico attribuito sulla base del luogo di ritrovamento), benchè abbia un aspetto moderno sia un diretto

Firenze: un nuovo antenato per la famiglia Hominidae inToscana
 ECCO LLUC, NUOVO ANTENATO DELL’UOMO ANSA
Scoperto nuovo antenato dell’uomo ANSA
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New Hominid 12 Million Years Old Found In Spain, With ‘Modern’ Facial Features

ScienceDaily (June 2, 2009) — Researchers have discovered a fossilized face and jaw from a previously unknown hominoid primate genus in Spain dating to the Middle Miocene era, roughly 12 million years ago. Nicknamed “Lluc,” the male bears a strikingly “modern” facial appearance with a flat face, rather than a protruding one. The finding sheds important new light on the evolutionary development of hominids, including orangutans, chimpanzees, bonobos, gorillas and humans.

In a study appearing in the Proceedings of the National Academy of Sciences, Salvador Moyà-Solà, director of the Institut Català de Paleontologia (ICP) at the Universitat Autònoma de Barcelona, and colleagues present evidence for the new genus and species, dubbed Anoiapithecus brevirostris. The scientific name is derived from the region where the fossil was found (l’Anoia) and also from its “modern” facial morphology, characterized by a very short face.

 

Lluc reconstruction. (Credit: Image courtesy of Universitat Autònoma de Barcelona) Lluc reconstruction. (Credit: Image courtesy of Universitat Autònoma de Barcelona)

 The research team at the ICP also includes collaborator David M. Alba, predoctoral researcher Sergio Almécija, postdoctoral researcher Isaac Casanovas, researcher Meike Köhler, postdoctoral researcher Soledad De Esteban, collaborator Josep M. Robles, curator Jordi Galindo, and predoctoral researcher Josep Fortuny.

Their findings are based on a partial cranium that preserves most of the face and the associated mandible. The cranium was unearthed in 2004 in the fossil-rich area of Abocador de Can Mata (els Hostalets de Pierola, l’Anoia, Barcelona), where remains of other fossilized hominid species have been found. Preparing the fossil for study was a complicated process, due to the fragility of the remains. But once the material was available for analysis, the results were surprising: The specimen (IPS43000) combined a set of features that, until now, had never been found in the fossil record.

Anoiapithecus displays a very modern facial morphology, with a muzzle prognathism (i.e., protrusion of the jaw) so reduced that, within the family Hominidae, scientists can only find comparable values within the genus Homo, whereas the remaining great apes are notoriously more prognathic (i.e., having jaws that project forward markedly). The extraordinary resemblance does not indicate that Anoiapithecus has any relationship with Homo, the researchers note. However, the similarity might be a case of evolutionary convergence, where two species evolving separately share common features.

Lluc’s discovery may also hold an important clue to the geographical origin of the hominid family. Some scientists have suspected that a group of primitive hominoids known as kenyapithecines (recorded from the Middle Miocene of Africa and Eurasia) might have been the ancestral group that all hominids came from. The detailed morphological study of the cranial remains of Lluc showed that, together with the modern anatomical features of hominids (e.g., nasal aperture wide at the base, high zygomatic rood, deep palate), it displays a set of primitive features, such as thick dental enamel, teeth with globulous cusps, very robust mandible and very procumbent premaxilla. These features characterize a group of primitive hominoids from the African Middle Miocene, known as afropithecids.

Interestingly, in addition to having a mixture of hominid and primitive afropithecid features, Lluc displays other characteristics, such as a very anterior position of the zygomatic, a very strong mandibular torus and, especially, a very reduced maxillary sinus. These are features shared with kenyapithecines believed to have dispersed outside the African continent and colonized the Mediterranean region, by about 15 million years ago.

In other words, the researchers speculate, hominids might have originally radiated in Eurasia from kenyapithecine ancestors of African origin. Later on, the ancestors of African great apes and humans would have dispersed again into Africa — the so-called “into Africa” theory, which remains controversial. However, the authors do not completely rule out the possibility that pongines (orangutans and related forms) and hominines (African apes and humans) separately evolved in Eurasia and Africa, respectively, from different kenyapithecine ancestors.

The project at els Hostalets de Pierola is continuing and, the researchers anticipate, more fossil remains will be found in the future that will provide key information to test their hypotheses.


Journal reference:

  1. Salvador Moyà-Solà, David M. Alba, Sergio Almécija, Isaac Casanovas-Vilar, Meike Köhler, Soledad De Esteban-Trivigno, Josep M. Robles, Jordi Galindo, and Josep Fortuny. A unique Middle Miocene European hominoid and the origins of the great ape and human clade. Proceedings of the National Academy of Sciences, 2009; DOI: 10.1073/pnas.0811730106

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Other Links:

  • In English

Our earliest hominid ancestors may have been European

Thaindian.com – ‎1-giu-2009‎
According to a report in New Scientist, the fossil, named Anoiapithecus brevirostris by Salvador Moya-Sola of the Catalan Institute of Palaeontology in

Researchers from the Institut Catala de Paleontologia describe a

EurekAlert (press release) – ‎2-giu-2009‎ – The new hominid has been given the scientific name of Anoiapithecus brevirostris, in reference to the region where the town of els Hostalets is situated

Найденные останки Anoiapithecus brevirostris. Фото National

Lenta.ru – ‎9 ore fa‎
Они отмечают, что важность находки Anoiapithecus brevirostris безусловна, но вот выводы ученых могут быть ошибочны. В частности, специалисты говорят,
  • In GERMAN

Aus Europa nach Afrika und wieder zurück

wissenschaft.de – ‎19 ore fa‎ – Die Anoiapithecus brevirostris genannte Art hat sich vor rund zwölf Millionen Jahren in Europa entwickelt und wanderte von dort aus nach Afrika ein,

Unser spanisches Erbe sueddeutsche.de

 Knochenfund Stammt der Mensch aus Spanien? Bayerischer Rundfunk. Hominiden-Fossil Waren unsere frühesten Vorfahren Europäer? ZEIT ONLINE

All news in German

  • In SPANISH – ESPANOL

Investigadores catalães definem espécie Anoiapithecus brevirostris

Ciência Hoje – ‎44 minuti fa‎
Os cientistas baptizaram esta nova espécie de Anoiapithecus brevirostris (pois o fóssil foi encontrado em Anoia) eo ser de Lluc (aquele que ilumina).

Fóssil de Lluc ‘ilumina’ história dos hominídeos Diário de Notícias – Lisboa

giugno 3, 2009 Posted by | - Mammiferi, - Ominidi, - Primati, An. Vertebrates, Articolo sc. di riferimento, Cenozoic, Europa, Lang. - German, Lang. - Italiano, P - Paleoantropologia, P - Ritrovamenti fossili, Paleontology / Paleontologia, X - PNAS | Lascia un commento

2009-05-19 – Chlamydoselachus anguineus: denti di squalo nelle colline senesi (shark teeth)

Denti di squalo prestorico nelle colline del Chianti

Sono stati rinvenuti nel cuore delle ‘crete senesi’ centinaia di denti fossili di Chlamydoselachus anguineus, una specie di squalo che oggi vive nelle profondità oceaniche. La scoperta prova che milioni di anni fa al posto delle zone in cui si produce Chianti e del Brunello ci fossero fondali marini profondi fin quasi due chilometri

Siena, 18 maggio 2009 – Nel cuore delle ‘crete senesi’, precisamente nella zona di Castelnuovo Berardenga (Siena),  sono stati ritrovati centinaia di denti fossili di squalo. I reperti sono da attribuire al Chlamydoselachus anguineus, una specie di squalo dalla forma sinuosa piu’ simile ad un anguilla che ad un pesce che oggi popola le profondità oceaniche. La scoperta è stata fatta da Simone Casati e Marco Zanaga del Gruppo di mineralogia e paleontologia (Gamps) di Scandicci (Firenze), che la definiscono eccezionale perché prova che milioni di anni fa al posto delle zone tipiche di produzione del Chianti e del Brunello ci fossero fondali marini profondi fin quasi due chilometri.
I reperti sono ritenuti rilevanti anche per quantità e qualità: nessun museo al mondo ne possiede interi, sono stati raccolti in tre anni di ricerche. I risultati, frutto di tre anni di ricerche, sono stati pubblicati sulla rivista internazionale Cainozoic research a cura del professor Franco Cigala Fulgosi, docente al dipartimento di scienze della terra di Parma, considerato fra i massimi esperti al mondo di squali fossili, e da Casati, Alex Orlandini e Davide Persico del gruppo fiorentino. Lo squalo Chlamydoselachus, spiegano gli esperti del Gamps, e’ un vero e proprio fossile vivente che a centinaia di metri al di sotto della superficie marina

fonte: LaNazione

maggio 19, 2009 Posted by | - Italia, - Pesci / Fishes, An. Vertebrates, Articolo sc. di riferimento, Cenozoic, Europa, Lang. - Italiano, P - Ritrovamenti fossili, Paleontology / Paleontologia | , , , , , , , , , | Lascia un commento

2009-05-12 – Darwinius masillae: l’anello mancante dell’evoluzione umana? (missing link of human evolution?)

Trovato l’anello mancante dell’evoluzione: un Adapide di oltre 37 milioni di anni fa

LONDRA (10 maggio) – La Bbc ha preparato uno straordinario documentario, presentato da David Attenborough, in cui rivelerà la scoperta di uno scheletro fossilizzato che rappresenterebbe l’anello mancante dell’evoluzione umana. Secondo il Mail on Sunday il documentario è top secret, ma fonti negli Usa dicono che la rivoluzionaria scoperta verrà presentata il prossimo 19 maggio da un gruppo di scienziati e documentaristi a New York. In quell’occasione verrà presentato il primo scheletro intero mai trovato di un particolare tipo di un animale che si chiamava Adapide, battezzato Darwinius masillae: le ossa fossilizzate, che hanno dai 37 ai 47 milioni di anni, sono stati trovati nella cava Messel in Germania, un sito famoso per i suoi fossili.

L’animale, una femmina, somiglia a un lemure (il mammifero dalla lunga coda che vive in Madagascar). Attenborough spiegherà che i ricercatori hanno concluso che quell’animale non è semplicemente un antenato dei lemuri (mancano diverse caratteristiche), ma fa parte di un gruppo collegato di primati che si sarebbero evoluti in scimmie ed esseri umani.

Lo studio cui fa riferimento la Bbc verrà pubblicato dalla rivista angloamericana “Public library of science”. Philip Gingerich, presidente della Us paleontological society, co-autore dello studio, ha detto al Mail: «Ho esaminato questo scheletro, è incredibilmente completo e datato con precisione. Lo abbiamo tenuto nascosto perché non si può parlare di qualcosa finché non la capisci a fondo. Ora abbiamo capito, farà progredire la nostra conoscenza dell’evoluzione». Interpellato sul documentario Bbc, Sir David ha risposto: «Temo di non essere autorizzato a parlarne».

fonte: IlMessaggero.it

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Is David Attenborough set to reveal the Missing Link in human evolution?

By Sharon Churcher

The BBC has made an extraordinary new documentary, presented by Sir David Attenborough, which will reveal the discovery of a fossilised skeleton that may be a vital ‘missing link’ in human evolution.

The 90-minute programme is top secret but The Mail on Sunday has learned from sources in America that the results of the study on which it is based will be revealed by a team of scientists and broadcasters in New York on May 19.

The centrepiece of the programme is the unveiling of the first-ever complete skeleton of an extinct animal called an adapid.

david attenborough

Relative values: Sir David Attenborough with a lemur – one of the creatures at the centre of the fossil debate

The fossilised bones, which are thought to be between 37 and 47million years old, were found in Germany’s Messel Shale Pit, a disused quarry near Frankfurt famous for its fossils.

The team who examined the young female animal say it has some resemblance to a lemur, a mammal with a distinctive tail that is found to this day in the forests of Madagascar.

But Sir David’s documentary will explain that the researchers have, controversially, concluded the fossil ‘is not simply a lemur’ but from a related group of primates which evolved into monkeys, apes and human beings.

The BBC programme is based on a scientific study to be published by the Public Library of Science, a leading academic journal with offices in Cambridge and San Francisco.

Last night, the study’s co-author, Philip Gingerich, the president-elect of the US Paleontological Society, said: ‘I examined this skeleton. It is exceptionally complete and it is well-dated.

We have kept it under wraps because you can’t blither about something until you understand it. We now understand it. It is going to advance our knowledge of evolution.’

Prof Gingerich confirmed he had spoken to Sir David.

The significance of the discovery, according to New York’s academic community, is that it could resolve the fierce debate about which kind of primates humans are descended from.

graphic

Some palaeontologists believe we evolved from the adapids – but that theory is hotly contested. The new skeleton appears to be a previously unknown type of adapid which would be the ‘missing link’ between small mammals and the apes which evolved into humans.

The study’s authors insist that the fossil can’t be a lemur because it lacks two features: the ‘toothcomb’, a set of lower front teeth used to groom fur; and ‘toilet claws’, toes on the hind feet used for scratching.

Half of the fossil was found a few years ago, but it was only when the rest of the body was discovered last year that scientists realised its importance.

The ground-breaking research was only possible after Norway’s National History Museum managed to buy the two parts of the fossil from private collectors.

The study, led by Norway’s Professor Jorn Hurum, says the fossil is so well-preserved that its soft tissues and stomach contents can be analysed.

Christened Darwinius masillae, it belonged to an extinct group of primates which lived in rainforests.

It was a female that was less than a year old but had been weaned and had developing teeth. It had nails rather than claws and would have weighed just 2lb when fully grown.

When asked about the BBC documentary, Sir David said: ‘I’m afraid I am not allowed to talk about it.’ Prof Hurum also refused to comment.
Why a wet nose could ruin research

While all the experts agree that the Messel fossil is an exciting discovery, some doubt that it will settle the debate about mankind’s ancestors.

Professor Matt Cartmill of Boston University, a leading authority on primates, said: ‘What remains to be shown is that this animal had features which link it decisively to higher primates.

If it turns out that it had a dry nose, like monkeys and people, rather than a wet nose like dog or a lemur, that could have a big impact on ideas about the origins of monkeys, apes and humans.’

Roger Thomas, secretary of the US Paleontological Society, said: ‘According to one group of thought, we are descended from the same primates as lemurs. Another argument is that hominids evolved from another small primate, the tarsiidae.’

Prof Cartmill added: ‘This specimen could settle that debate but, if I had to put my money on it, my expectation would be that they will not be able to tell one way or another.’

source: http://www.mailonsunday.co.uk/sciencetech/article-1179926/Is-David-Attenborough-set-reveal-Missing-Link-human-evolution.html

maggio 12, 2009 Posted by | - Mammiferi, - Ominidi, - Primati, 6 Eocene, An. Vertebrates, Articolo sc. di riferimento, Cenozoic, Europa, Lang. - Italiano, P - Evoluzione, P - Paleoantropologia, P - Ritrovamenti fossili, Paleontology / Paleontologia | , , , , , , , , , , , , , , , , , | 2 commenti