Paleonews

Il blog dedicato ai Paleontologi !!!!

2009-06-20 – Spagna, Teruel: trovato nuovo ornitopode (Spain, new Ornithopod) (Espana, nuevo ornitópodo)

Paleontologists of  Dinópolis Foundation have found the back leg of new a dinosaur ornithopod of small size near a vertebra and a tooth of the “Turiasaurus riodevensis”. These remains are been founded in the deposit going back to 145 million years ago of Barrihonda-El Chimney of Riodeva, in Teruel , Spain.
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El nuevo ornitópodo de Teruel

Pata trasera del ornitópodo encontrado en Teruel. / Fundación Dinópolis

Pata trasera del ornitópodo encontrado en Teruel. / Fundación Dinópolis

  • Hallan la pata trasera de un nuevo dinosaurio de pequeño tamaño
  • También han localizado una vértebra y un diente del ‘Turiasaurus riodevensis’

La pata de un nuevo dinosaurio, seguramente un ornitópodo de hace unos 145 millones de años, es el último tesoro paleontológico encontrado en el yacimiento de Barrihonda-El Humero de Riodeva, en Teruel, en las excavaciones de este año de la Fundación Dinópolis.

Junto con este fósil, ya han aparecido una vértebra y un diente más del gigantesco ‘Turiasaurus riodevensis’, considerado el más grande de Europa, cuyo esqueleto cada vez está más completo.

El hallazgo de la pata trasera del nuevo dinosaurio fue una auténtica sorpresa, como explica Luis Alcalá, director de la Fundación Dinópolis: “Apareció el primer día de las excavaciones en el yacimiento, que es una explanada del tamaño de un campo de baloncesto. Estaban limpiando la zona cuando toparon con el fósil, a unos cuatro metros del ‘Turiasaurus’. Enseguida vimos que era otro dinosaurio nuevo, del grupo de los ornitópodos, pero aún no sabemos de qué especie”, explica el paleontólogo.

Los ornitópodos eran dinosaurios de tamaño pequeño, unos cinco metros incluida la cola, que comían plantas y andaban a cuatro patas. No tenían armadura, ni cuernos ni colmillos; posiblemente las únicas defensas con que contaron fueron su pico grande y fuerte y la cresta (aunque solo algunos).

A pocos metros de este ejemplar, se ha encontrado una vértebra del gigante de Riodeva, así como otro diente. Completar lo más posible su esqueleto es el objetivo prioritario del proyecto de la excavación, cuando ya se tiene un 45%. También han salido a la luz restos de carnívoros, entre ellos uno de grandes dimensiones.

A falta de realizar un exhaustivo estudio de los últimos huesos, el director de la Fundación plantea que podría haber habido una avalancha o algún otro suceso natural que provocó la muerte simultánea de varios dinosaurios, debido a la gran acumulación de huesos que hay en el mismo sitio.

Hace unas semanas, los investigadores confirmaron que animales carnívoros, alguno de grandes dimensiones, habían devorado a ‘Turiasaurus’, en cuyos restos de la cadera se identificaron perforaciones hechas por las mordeduras.

Las excavaciones en este yacimiento continuarán hasta el 20 de julio, si sigue este ritmo de hallazgos. “No podemos sacar más fósiles de los que podemos estudiar en los ocho meses siguientes. Y también hay que preparar el material”, comenta Alcalá.

Hasta ahora, el yacimiento de Barrihonda-El Humero está siendo una mina. Junto con el gigante de Europa y varios carnívoros, se había encontrado un estegosaurio, y la lista aumenta ahora con el nuevo ornitópodo.

Rosa M. Tristán | Madrid

source: http://www.elmundo.es/elmundo/2009/06/16/ciencia/1245171379.html

Annunci

giugno 20, 2009 Posted by | - Ornitopodi, - R. Dinosauri, 2 Jurassic / Giurassico, An. Vertebrates, Europa, Mesozoic, P - Ritrovamenti fossili | , , , , | Lascia un commento

2009-06-01 – Lyme Regis, UK: trovato un nuovo Plesiosauro (new Plesiosaur)

Info in italiano: LaRepubblica

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Found: The Loch Ness monster –

that lived in the English Channel and died more than 200million years ago

By Eddie Wrenn
Last updated at 8:46 AM on 01st June 2009

 

 

 

It roamed the English channel more than 200 million years ago.

And now the prehistoric monster has surfaced once more – in the limestone of Lyme Regis’s famous ‘Jurassic Coast’.

Excited archaeologists discovered the Loch Ness-style creature on the beach and have spent months piecing together a giant jigsaw composed of dozens of old bones to reveal the 12ft-long plesiosaur.

The Plesiosaur was discovered by archeologists at Monmouth beach in Lyme Regis - known as England's 'Jurassic coast'

The Plesiosaur was discovered by archeologists at Monmouth beach in Lyme Regis – known as England’s ‘Jurassic coast’

The famous 1934 hoax picture, which helped spread the Loch Ness legendThe monster: The famous 1934 hoax picture, which helped spread the Loch Ness legend

The marine reptile hunted the oceans with a long thin neck and tail, four large flippers and razor-sharp teeth.

It existed during the Jurassic period about 150 to 200 million years ago when what is now the Channel was a shallow, tropical sea.

The remains were discovered by fossil hunter Tracey Marler under rocks on Monmouth Beach near Lyme Regis, Dorset.

She first found a single bone in limestone. She and partner Chris Moore, an expert in fossils, returned to the scene and they found four more bones.

As experts examined the bones in detail, they were surprised to see teeth marks from where a predator dinosaur would have feasted on the carcass of the ‘lake monster’.

 

 

Fragments: The skeleton is 70 per cent complete and will soon go on display to the publicFragments: The skeleton is 70 per cent complete and will soon go on display to the public

After further excavation about 150 vertebrae bones and parts of its skull and jaw, with one tooth remaining, were uncovered.

Mr Moore said: ‘It came out in pieces but you could clearly see how it looked.

‘The tail bone was in position, and some of the back bones were completely in place where they should be and the neck bone was there as well.

‘You could see some of the bones had actually been chewed up a bit.

‘There are teeth marks and you can see how the skeleton had been torn apart by some other nasty marine reptile.’

 

 

More…

 

Mr Moore added: ‘Their predator would have been the ichthyosaur which was carnivorous.’

Natural England worked closely with the Jurassic Coast World Heritage Site team to carefully extract the fossils.

The alternative of leaving it could have led to it being destroyed by ill-informed collectors or eventually being washed away and eroded by the sea.

Richard Edmonds, science manager for the Jurassic Coast World Heritage Site, said: ‘There was a risk that we could have damaged the pavement by the act of removing the fossil.

‘Plesiosaur remains are rare. There are only 10 known examples of complete or even partial skeletons of this species.

‘I have been doing this for 30-odd years and I have only ever found the odd bone.

‘The specimen could not have been in a more sensitive location, in the famous and iconic ammonite pavement.’

It is hoped the skeleton, which is 70 per cent complete, will go on public display at the Lyme Regis Museum.

source: dailymail.co.uk

giugno 1, 2009 Posted by | - Plesiosauri, - Rettili, 2 Jurassic / Giurassico, An. Vertebrates, Europa, Lang. - Italiano, Mesozoic, P - Ritrovamenti fossili, Paleontology / Paleontologia | , , , , | Lascia un commento

2009-03-15 – Impronte di dinosauri rimosse dalla “Jurassic Coast” (Dinosaur print stolen)

 Lastre contenenti impronte di dinosauri sono state rimosse dalla famosa Jurassic Coast (Gran Bretagna meridionale) per proteggerle

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Dinosaur print stolen from quarry

Dinosaur footprints
Another 25 slabs with fossil footprints have now been moved to safer place

A 135-million-year-old fossilised dinosaur footprint has been stolen from a quarry in Dorset.

The print was chiselled out of a limestone slab at Coombefield Quarry on the Jurassic Coast on Portland sometime over the last six months.

Another 25 slabs with fossil footprints have now been moved to a safer place.

Portland Gas Storage Ltd, which plans to build a storage facility, set up a trust to safeguard unearthed prints.

‘Treasured items’

The other slabs bear the footprints of dinosaurs including the two-legged herbivore iguanadon and the four-legged herbivore sauropod.

They were all – including the 18-inch one that was stolen – unearthed by quarrying at the Stone Firms Ltd site in 2002.

Portland Gas Trust manager, Rachel Barton said: “Aside from the risk of vandalism or theft by some elements of the public, their previous setting was a busy working site exposing the treasured items to unnecessary risk.

“Safeguarding these historic footprints supports the trust’s key aims to benefit projects connected with Portland.”

The company’s gas storage facility will comprise 14 underground storage caverns to hold 1% of the UK’s annual demand for natural gas.

The trust plans to put the footprints on display at a new £1.5m visitor centre.

source: BBC

marzo 15, 2009 Posted by | - R. Dinosauri, 2 Jurassic / Giurassico, Europa, Mesozoic, P - Geositi, Paleontology / Paleontologia | , , , , | Lascia un commento

2009-03-07 – Coahuila, MEX: the oldest chelonid turtle

Oldest sea turtle fossil unveiled in Mexico

“It is the oldest sea turtle of its kind and it belongs to the chelonia family. The oldest specimen of this species up to now was 65 million years old and was found in New Jersey, United States,” the INAH said in a statement.

The fossils of seven sea turtles were found at different sites in Coahuila, the state that Mexican scientists call “the paradise of paleontology.”

The sea turtle inhabited the northern region in the late Cretaceous period, 72 million years ago, and is the ancestor of the present day green turtle, the institute said.

It was one meter (yard) long, 70 centimeters (28 inches) wide and distinguished from other turtles by its rounded head.

source: AFP

marzo 7, 2009 Posted by | - Rettili, 2 Jurassic / Giurassico, America Central, An. Vertebrates, Mesozoic, P - Ritrovamenti fossili, Paleontology / Paleontologia | , , , , , | Lascia un commento

2009-03-05 – Teropodi con postura da uccelli (Dinosaur imprints, birdlike arm anatomy)

Tracce di un Teropode a riposo (Giurassico inferiore, Utah – USA) rivelano una postura da uccello

Vedi approfondimento sul Blog Theropoda:

Un nuovo sito icnologico dimostra che i theropodi si accucciavano come… (Milner et al., 2009)

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Sitting dinosaur leaves karate chop handprints – March 04, 2009

45376624.jpgAncient meat-eating dinosaurs held their arms with palms facing inwards like their bird descendants, a rare set of 198-million-year-old fossilised handprints has revealed. An analysis of the prints, published this week in PLoS One, supports theories that even very early therapods [lit. ‘beast feet’] such as tyrannosaurs and velociraptors had bird-like forelimbs, and walked only on two legs, well before they evolved feathery wings.

The handprints came from a dinosaur that sat down on the edge of a lake in St George, Utah, and extended its arms far enough to leave sediment marks. Six other resting dinosaur traces have been reported before, but they all lack clear hand prints.

This means, reports the Chicago Tribune, that we must banish images of tyrannosaurs holding their forearms like monkeys, with palms facing downwards – a posture that palaeontologists apparently term the “bunny position” – as depicted in Jurassic Park. Instead, we must imagine that dinosaurs were extremely good at holding basketballs.

“What this seems to imply is that, even from fairly early in their history, dinosaurs were entirely bipedal and weren’t using their forearms to support themselves in any way,” paleontologist Tom Holtz of the University of Maryland, says. “Because of that, the hands could specialize as weapons, to grab on to a struggling animal or to fight with other dinosaurs.”

Image: Dilophosaurus wetherilli in bird-like resting pose/Heather Kyoht Luterman

source: Nature.com

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What a dinosaur handprint reveals

Los Angeles Times – ‎3-mar-2009‎
At left, dinosaur tracks with hand prints show bird-like inward-facing palms at Johnson Farm, Utah. At right, an artist’s reconstruction shows the formation
National Geographic —————————————————————————–

 

 free access article on PlosOne

Bird-Like Anatomy, Posture, and Behavior Revealed by an Early Jurassic Theropod Dinosaur Resting Trace

Andrew R. C. Milner, Jerald D. Harris, Martin G. Lockley, James I. Kirkland, Neffra A. Matthews

Abstract PDF

 

 

marzo 5, 2009 Posted by | - R. Dinosauri, - Teropodi, - Uccelli / Birds, 2 Jurassic / Giurassico, America Northern, An. Vertebrates, Articolo sc. di riferimento, Bl - Top posts, FREE ACCESS, Mesozoic, P - Evoluzione, P - Impronte, P - morfologia funzionale, P - Paleoetologia, P - Ritrovamenti fossili, Paleontology / Paleontologia | , , , , , | Lascia un commento

2009-02-25 – Miragaia longicollum: nuovo dinosauro scoperto in Portogallo (New dinosaur, Portugal)

on other blogs: SVPOW – SV-POW! showdown: stegosaurs vs sauropods

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New dinosaur discovered in Portugal

A new dinosaur that walked the Earth 150 million years ago has been found in Portugal

Its partial skeleton includes the only known skull remains from any European stegosaur that had a row of bony plates along its back and a spiked tail probably used as a weapon.

The plant eating creature has been called, Miragaia longicollum, after the village it was uncovered in near Lourinha and because of its long neck.

Stegosaurs are normally known for their short forelimbs and short necks, and are generally considered to be low browsers.

But this new dinosaur has a higher neck vertebrae count than most of the sauropods renowned for their small heads on very long necks that were the largest and heaviest dinosaurs that ever existed.

Dr Octavio Mateus, of the New University of Lisbon, said: “Stegosaurs are traditionally reconstructed as feeding on low vegetation because of their small heads, short necks and short forelimbs.

“We describe a new stegosaurian dinosaur from the Upper Jurassic of Portugal that challenges this traditional view.

“Miragaia longicollum possessed at least 17 cervical vertebrae, more than possessed by most sauropod dinosaurs, famed for their long necks.

“This new discovery indicates a previously unsuspected level of ecological diversity among stegosaurs.”

Dr Mateus, whose findings are described in Proceedings of the Royal Society B, said several elements of the skull of Miragaia longicollum were found, “representing the first such material recovered from a European stegosaur.”

He added: “The most notable feature of M. longicollum is its long neck, with at least 17 cervical vertebrae.

“The specimen here described represents one of the most complete stegosaurs in Europe and the first that includes cranial material.”

source: telegraph.co.uk

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Miragaia longicollum

Miragaia longicollum

Stegosaurs have long been identified by the bony plates on their backs, the spikes on their tales, short forelimbs, and stubby little necks.
Now paleontologists have discovered a 150-million-year-old stegosaur (above) in Portugal with a neck that stretched over 5.9 feet (1.8 meters), a February 2009 study reported.
Photograph courtesy Octavio Mateus/Nova de Lisboa University; illustration courtesy Alam Lam/Nova de Lisboa University

source: NationalGeographic.com

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New dinosaur discovered in Portugal
Telegraph.co.uk – 15 ore fa
A new dinosaur that walked the Earth 150 million years ago has been found in Portugal. Its partial skeleton includes the only known skull remains from any European stegosaur that had a row of bony plates along its back and a spiked tail probably used
Long-Necked Stegosaur Defies Reputation Discovery Channel
New Stegosaur With Odd Long Neck Discovered National Geographic
Science News – Daily News & Analysis
e altri 16 articoli simili »

febbraio 25, 2009 Posted by | - R. Dinosauri, 2 Jurassic / Giurassico, An. Vertebrates, Bl - Top posts, Blogs, Europa, P - Ritrovamenti fossili, Paleontology / Paleontologia, SVPOW | , , , , , , | 3 commenti

2009-01-19 – Anchiornis: un nuovo dinosauro piumato (primitive feathered dinosaur)

Un nuovo dinosauro piumato scoperto in Cina, l’Anchiornis, può aiutare a comprendere meglio la “transizione” da dinosauri ad ucccelli essendo “più basale di Archaeopteryx.

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New Feathered Dinosaur Adds to Bird Evolution Theory

Kevin Holden Platt in Beijing
for National Geographic News
January 16, 2009

A fossil of a primitive feathered dinosaur uncovered in China is helping scientists create a better model of how dinosaurs evolved into modern birds.

The winged dinosaur is still in the process of being dated, and might have lived toward the end of the Jurassic period, which lasted from 208 to 144 million years ago.

Anchiornis - A fossil of a primitive feathered dinosaur uncovered in China (above) is helping create a better model of how dinosaurs evolved into modern birds, experts said in January 2009.

Anchiornis - A fossil of a primitive feathered dinosaur uncovered in China (above) is helping create a better model of how dinosaurs evolved into modern birds, experts said in January 2009. - Photograph courtesy Xu Xing

In many ways, it is “more basal, or primitive, than Archaeopteryx,” said paleontologist Xu Xing at Beijing’s Institute of Vertebrate Paleontology and Paleoanthropology. Archaeopteryx, the earliest known bird, lived 150 million years ago.

The protobird is “very close to the point of divergence” at which a new branch of winged dinosaurs first took flight, said Xu.

The new species, called Anchiornis huxleyi, was discovered in the ashes of volcanoes that were active during the Jurassic and Cretaceous (144 to 65 million years ago) periods in what is now northeastern China.

(Read about the prehistoric world.)

Anchiornis, which is Greek for “close to bird,” measured just 13 inches (34 centimeters) from head to tail and weighed about 4 ounces (110 grams).

The dinosaur’s body and forelimbs were covered with feathers, and it “might have had some aerial capability,” Xu said.

Anchiornis is one of the smallest theropod dinosaurs ever uncovered,” Xu explained. Theropods were a group of carnivorous dinosaurs that walked on two legs.

Taking Wing

The fossil provides new clues about how feathers, wings, and flight progressively appeared among theropods, along with evidence that certain types of feathered dinosaurs decreased in stature even as their forelimbs became elongated.

The compact structure of Anchiornis “reinforces the deduction that small size evolved early in the history of birds,” Xu explained”[Anchiornis] exhibits some wrist features indicative of high mobility, presaging the wing-folding mechanisms seen in more derived birds,” he said.

“The wrist is a big part of the formation of wings, and pivotal to flight,” Xu added. “During flight, steering and flapping greatly depend on the wrist.”

Despite this protobird’s relatively advanced feathers and wrist, it is unclear if Anchiornis could actually engage in powered flight.

“Behavior and biomechanics are very difficult to determine solely from the fossil record, and perhaps flight is impossible to determine,” said Mark Norell, chairman and curator of the division of paleontology at the American Museum of Natural History in New York.

“Feathers have lots of functions, and probably evolved as thermoregulators,” said Norell, who closely examined the fossil during a trip to Beijing.

“Dinosaurs might have used feathers for sexual display or to make themselves appear bigger, or as camouflage to avoid predators,” he said.

Patterns of spots and bars evident on one species of feathered dinosaur from China might have functioned as a camouflage defense, Norell added.

(Related: “First Dinosaur Feathers for Show, Not Flight?” [October 22, 2008].)

Prehistoric Paradise

Xu said that the region in northeastern China where most of the world’s feathered dinosaurs, including Anchiornis, have been discovered is a virtual paradise for dinosaur hunting.

“This area has three circles of volcanic activity,” with eruptions that intermittently covered and preserved entire biospheres starting from the early Jurassic.

“Volcanos periodically killed the animals and plants and preserved them perfectly in volcanic ash,” he said.

“Sometimes the volcanic ash even preserves soft tissues, leaving behind an exceptional 3-D fossil.”

source: http://news.nationalgeographic.com/news/2009/01/090116-feathered-dinosaur_2.html

gennaio 19, 2009 Posted by | - R. Dinosauri, - Teropodi, - Uccelli / Birds, 2 Jurassic / Giurassico, Asia, Italiano (riassunto), Mesozoic, P - Evoluzione, P - morfologia funzionale, P - Ritrovamenti fossili, Paleontology / Paleontologia | , , , , , , , , , , | Lascia un commento

2008-11-25 – Skye Isle, UK: Tartarughe e Dinosauri (Turtles and Dinosaurs)

 Le imponte di dinosauri giurassici dell’Isola di Skye sono analoghe a quelle ritrovate nel Wyoming, a testimonianza di una connessione spaziale nel Giurassico tra le due aree.

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Jurassic isle still has secrets

By Steven McKenzie
Highlands and Islands reporter, BBC Scotland news website

Richard Sowersby/BBC
Dr Neil Clark said Skye is the site of significant finds about once every 10 years

Erosion will see fossils-rich Skye give up more secrets of the prehistoric past, an expert has predicted.

Dr Neil Clark, of University of Glasgow’s Hunterian Museum and Art Gallery, said it was one of the world’s most important paleontological sites.

Its standing is underlined by the number of finds from the Middle Jurassic, about 170 million years ago.

Evidence of the earliest turtles known to live in water has also been discovered on the isle.

Why there are so few sites is something I have thought about, but have not come up with an answer
Dr Neil Clark
Hunterian Museum

Dr Clark said: “There is always something new turning up on Skye.

“People are making finds that are maybe not new in world-wide terms but to them on an individual basis, but once every 10 years something that is very important is found.

“Skye is a very important palaeontology site.

“The cliffs on the island are quite high and not easy to get to but bad weather and erosion means fossils are being added to the beaches every year.”

In 2002, the discovery of the biggest, and best, dinosaur tracks ever found in Scotland were confirmed on Skye.

Research by Dr Clark and Dr Michael Brett-Surman, of the Smithsonian Institution in Washington, US, has suggested they were left by the same dinosaurs or a similar species that once roamed Wyoming.

Last week, the discovery of the earliest turtles known to live in water was reported in the Royal Society journals.

Vital clues

The 164 million-year-old reptile fossils were found on a beach on southern Skye.

The new species forms a missing link between ancient terrestrial turtles and their modern, aquatic descendants.

Dr Clark said the island has provided vital clues to life during the Middle Jurassic.

He said: “Skye is very important for world-wide palaeontology, mainly because of the number of Middle Jurassic sites around the world is not that great.

“Why there are so few sites is something I have thought about, but have not come up with an answer.

“I guess there has not been enough exposure of the right kind of rocks and maybe because of the higher sea levels of today.”

 http://news.bbc.co.uk/2/hi/uk_news/scotland/highlands_and_islands/7739306.stm

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BBC News

Jurassic Skye: When dinosaurs roamed Scottish island
Scotsman – 10 ore fa
Clark says: “The importance of this apparent link between Skye and Wyoming is that the Americans don’t actually have any dinosaur remains, apart from these footprints, from this particular period, the mid-Jurassic, whereas we have the bones of a number
Skye’s dinosaur connection to US BBC News
Dinosaur in Skye, UK Linked to Dinosaur in Wyoming, US ShortNews.com
BBC News
e altri 13 articoli simili »

novembre 25, 2008 Posted by | - R. Dinosauri, - Rettili, 2 Jurassic / Giurassico, Europa, Italiano (riassunto), P - Paleogeografia, P - Ritrovamenti fossili, Paleontology / Paleontologia | , , , , , , , , | Lascia un commento

2008-11-25 – Svizzera: estratte ossa di Metriorhynchus

PALEONTOLOGIA:SVIZZERA; SCOPERTO COCCODRILLO 150 MLN ANNI FA

(ANSA) – GINEVRA, 24 NOV – Paleontologi svizzeri hanno scoperto lo scheletro di un coccodrillo, il metriorinco (Metriorhynchus), vissuto 150 milioni di anni fa. L’eccezionale scoperta – riferisce oggi l’agenzia di stampa svizzera Ats – e’ stata compiuta a Courtedoux, nel cantone elvetico del Giura, durante i lavori di costruzione di un’ autostrada. Da vivo il rettile raggiungeva un peso di 300 kg e per estrarlo senza danneggiare le ossa i paleontologi hanno dovuto toglierlo in un blocco di roccia di tre tonnellate. Sono trascorsi sei mesi tra la sua scoperta e la sua estrazione. L’Ajoie era 150 milioni di anni fa una regione bordata da un mare caldo, scrive l’Ats. La regione di Courtedoux e’ considerata come il terzo sito per importanza al mondo per quel che riguarda le impronte di dinosauri, con circa 5000 orme identificate. (ANSA). XBV
24/11/2008 18:21

http://www.ansa.it/ambiente/notizie/notiziari/natura/20081124182134775453.html

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Other languages links:

 

Prehistoric crocodile comes ashore
Swissinfo – 13 ore fa
Up until now, discoveries of the metriorhynchus have only been made in a handful of countries, including Britain, France, Germany, Argentina and Chile.
Ein jurassischer “Metriorhynchus
Swissinfo – 17 ore fa
Metriorhynchus: So heisst dieser Vorläufer des Krokodils, der zum ersten Mal in der Schweiz entdeckt wurde. Das Skelett wurde am Montag im Kanton Jura
150 Millionen Jahre altes Meereskrokodil entdeckt NZZ Online
150 Millionen Jahre altes Krokodil-Skelett in der Schweiz freigelegt AFP
e altri 11 articoli simili »

Radio Suisse Romande
Ajoie: découverte d’un crocodile vieux de 150 millions d’années
Romandie.com – 15 ore fa
Le squelette d’un crocodile marin qui a vécu il ya 150 millions d’années, le Metriorhynchus, a été mis au jour, une première en Suisse.
Après les dinosaures, le Jura se découvre un crocodile marin Le Temps (Abonnement)
Suisse: exhumation d’un crocodile vieux de 150 millions d’années Le Monde
Découverte d’un squelette de crocodile marin vieux de 152 millions 7sur7
La Tribune.fr – TSR.ch
e altri 29 articoli simili »

novembre 25, 2008 Posted by | - R. Dinosauri, - Rettili, 2 Jurassic / Giurassico, Europa, Lang. - Italiano, P - Impronte, P - Ritrovamenti fossili, Paleontology / Paleontologia | , , , , , , , | Lascia un commento

2008-11-24 – Eileanchelys waldmani: la prima tartaruga acquatica ? (sea-turtle missing link)

Reperti fossili di un genere di tartaruga ritrovati nel Giurassico scozzese aiutalo a comprendere il passaggio da una vita terrestre ad una marina.

I reperti di Eileanchelys waldmani rappresentano infatti una foma di passaggio in quanto sebbene adattati alla vita acquatica (ritrovati in sedimenti di laguna assieme a squali e altri organismi marini) presentno caratteristiche del cranio tipiche di esemplari terresti.

Inoltre sono comunque molto somiglianti a un genere attuale a prova della “bontà” del progetto evolutivo delle tartarughe acquatiche.

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Scottish turtle is missing link

Monday, 24 November 2008
Cosmos Online

LONDON: Turtles normally evoke images of tropical seas, but palaeontologists have found the 164-million-year-old remains of one of the first known water-dwelling turtles on a chilly Scottish island.

These unique fossils bridge what has been a 65-million-year gap in the fossil record primitive land-based turtles and modern turtles, many of which live in the open ocean, said Jérémy Anquetin, based at both University College London (UCL) and the Natural History Museum, in England.

Rugged an beautiful

Against the rugged and beautiful backdrop of the Isle of Skye, his team have unearthed six fossils of a species called Eileanchelys waldmani. The discoveries are described in the British journal the Proceedings of the Royal Society B.

Similar fossils from the Middle Jurassic have been found in the U.S., Argentina, and Russia, but Anquetin’s are the most complete yet discovered and offer new clues about the tricky transition from land to water.

Though it seems an unlikely place to find tropical animals today, “Scotland was much farther south [in the Jurassic]… its position would not have been tropical, but its climate may have been,” said Anquetin.

These turtles would have shared their lagoon and lake environment with sharks and salamanders, whose remains have also been found at the site, he said.

Remarkable similarities

Despite the antiquity of the fossils, the species have some remarkably similar features to turtles found today, particularly a primitive freshwater species called the red-eared slider, found in the southeast of the U.S. and Mexico.

One major difference is that the skull of the fossil is more “reptilian” than modern turtles, said Anquetin. However, the overall body shape, or morphology of these turtles has changed very little over million of years, especially when compared with the transformations seen in mammals.

“I like to think [turtles] are an evolutionary success … because their body plan is still working,” said Anquetin, who added that (like crocodiles) they have outlived many catastrophes including numerous ice ages and mass extinctions.

The exciting research is helping plug a 65 million year gap in the fossil record, commented Walter Joyce a vertebrate palaeontologist and fossil turtle expert at the University of Tuebingen in Germany.

“The new fossil is finally giving us a glimpse of how early turtles evolved,” he said. “The authors make a compelling case that by this stage in evolution turtles had started moving into aquatic habitats.”

http://www.cosmosmagazine.com/news/2367/scottish-turtle-missing-link

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Scientific article:

Jérémy Anquetin, Paul M. Barrett, Marc E.H. Jones, Scott Moore-Fay and Susan E. Evans
Abstract

 The discovery of a new stem turtle from the Middle Jurassic (Bathonian) deposits of the Isle of Skye, Scotland, sheds new light on the early evolutionary history of Testudinata. Eileanchelys waldmani gen. et sp. nov. is known from cranial and postcranial material of several individuals and represents the most complete Middle Jurassic turtle described to date, bridging the morphological gap between basal turtles from the Late Triassic–Early Jurassic and crown-group turtles that diversify during the Late Jurassic. A phylogenetic analysis places the new taxon within the stem group of Testudines (crown-group turtles) and suggests a sister-group relationship between E. waldmani and Heckerochelys romani from the Middle Jurassic of Russia. Moreover, E. waldmani also demonstrates that stem turtles were ecologically diverse, as it may represent the earliest known aquatic turtle.

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novembre 24, 2008 Posted by | - Rettili, 2 Jurassic / Giurassico, Articolo sc. di riferimento, Europa, Italiano (riassunto), P - Ritrovamenti fossili, Paleontology / Paleontologia | , , , , , , , , , , | 1 commento