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2009-04-09 – Zone BS: Scoperte impronte di rettili risalenti al Triassico (Triassic reptile footprint from Italy)

Paleontologia, scoperte orme fossili nei pressi del lago di Iseo

9 aprile 2009 – Alcune passeggiate fossili di rettili predatori, ritenuti antenati dei dinosauri, sono state rinvenute su una parete di roccia nei pressi del paese di Zone, nei dintorni del lago di Iseo. Le 70 orme, il cui diametro varia dai 12 ai 40 centimetri, a detta del team di paleontologi italiani che le hanno studiate, risalgono al periodo Triassico, approssimativamente a 220 milioni di anni fa. Secondo gli studiosi – che renderanno noti i risultati della loro ricerca, eseguita anche con tecnica laser, il 16 aprile al Museo di Storia naturale di Milano – quelle rinvenute nel Bresciano sono le più grandi, e tra le più antiche, tracce fossili finora scoperte in Italia. I rettili che le hanno lasciate dovrebbero essere dei precursori dei dinosauri e, secondo i paleontologi, per un certo periodo avrebbero coabitato con loro, finendo per trovarsi anche in competizione, fino a esserne soppiantati. La grandezza delle loro orme, dai 12 ai 40 centimetri, potrebbe depistare sulle loro dimensioni, spingendo a ritenerli quasi degli animaletti domestici: in realtà i rettili triassici non appoggiavano a terra tutta la pianta e, dalla distanza tra un passo e un altro, e tra impronte posteriori e anteriori, gli studiosi hanno ricavato l’idea che dovessero raggiungere anche i sei metri di lunghezza. In confronto a rettili contemporanei come i coccodrilli, poi, avevano una maniera di camminare stranamente più evoluta: dalla mancanza della scia di trascinamento della coda, gli studiosi hanno ritenuto che i loro arti erano in posizione verticale sotto il corpo e che quindi camminavano con ventre e coda ben lontani dal terreno. Una tecnica subito imitata dai loro successori, i dinosauri, che li avrebbero poi eliminati. La sfortuna di questi rettili, d’altronde, per gli studiosi, è proprio che “tentarono di diventare dinosauri, senza riuscirci”. E così l’evoluzione li portò all’estinzione. Lo si apprende dall’Ansa. Last Updated ( giovedì, 09 aprile 2009 )

source: http://www.fondazioneitaliani.it/index.php/en/Paleontologia-scoperte-orme-fossili-nei-pressi-del-lago-di-Iseo.html

Annunci

aprile 9, 2009 Posted by | - Italia, - Rettili, 3 Triassico, An. Vertebrates, Europa, Lang. - Italiano, Mesozoic, P - Impronte, Paleontology / Paleontologia | , , , | Lascia un commento

2008-10-10 – Germania: Dinosauri più antichi? (3) (Dinosaur,Triassic, track)

Debate Rages over ‘Oldest Dinosaur’ Find in Germany

By Philip Bethge

A scientist in the eastern German state of Saxony-Anhalt believes he has uncovered tracks from the world’s oldest dinosaur. But the footprints at the center of the find have sparked a major debate among scientists.

Are the evolutionary "missing link" between reptiles of the Paleozoic era and the later, lithe dinosaurs?
Landesamt für Denkmalpflege und Archäologie Halle

Purported dinosaur tracks in Bernburg, Germany: Are the evolutionary “missing link” between reptiles of the Paleozoic era and the later, lithe dinosaurs?

A massive creature tromped its way across an expansive limestone marsh. Horseshoe crabs scurried in its wake, and a reptile similar to a crocodile crossed its path. Weighing between 600 and 800 kilograms (1,760 pounds), the creature left impressive footprints in the limestone deposit. Shifting sand then covered the tracks. The creature’s rear foot measured a large 35 centimeters (14 inches). 

All this happened around 243 million years ago — and it took until now for the fossilized tracks of this massive reptile to come to light again. The find was made in a quarry near Bernburg, a small city in the eastern German state of Saxony-Anhalt, and the first details were revealed last week. If the discoverer, paleontologist Cajus Diedrich, is to be believed, these limestone impressions will make for a research coup of global dimensions.

Diedrich believes he’s found the world’s oldest dinosaur, the ancestor of T. rex, Brontosaurus, Triceratops and all the others. The German weekly newsmagazine Stern obligingly reported the paleontological discovery was a “sensation,” but a number of experts in the field believe Diedrich’s theory is fundamentally wrong and an all-out scientific brawl is brewing within the profession.

Here are the facts: Diedrich first came across the site in late 2007. In June 2008, together with specialists from Saxony-Anhalt’s state Office for Monument Protection and Archeology in the nearby city of Halle, he retrieved material from the limestone quarry near Bernburg from an area about half the size of a soccer field. There they found fossilized tracks from many kinds of reptiles and crabs, as well as skeletal impressions of marine reptiles.

But the set of tracks that Diedrich describes as “spectacular” is the same one making waves among paleontologists now. Covering almost 50 meters (164 feet), it includes 34 individual impressions, each showing five toes. According to Diedrich, the anatomy of the footprints leaves no doubt: “There were relatively large dinosaurs far earlier than previously assumed.”

Diedrich speaks of the Prosauropods, dinosaur ancestors of the long-necked giants who later grazed the plains of the Jurassic period. He sees his find as the evolutionary “missing link” between the slow reptiles of the Paleozoic era and the later, lithe dinosaurs.

But the freelance paleontologist has attracted criticism with his theory. It’s “ridiculous,” declares Hartmut Haubold, a paleontologist from Halle. “It’s as if someone found a 10-million-year-old stone and claimed it was a hand axe made by humans.” Dinosaurs didn’t come into existance until a good 15 million years later than Diedrich claims,” he says.

 Haubold believes the tracks in question, were most likely left by a Chirotherium, an ancestral reptile long known to scientists and possibly related to the dinosaurs’ predecessors. Martin Sander, a paleontologist at Germany’s Bonn University, is also skeptical. “The first dinosaurs were smaller creatures,” he explains, “about as big as monitor lizards.” That a much larger dinosaur would have lived so much earlier, says Sander, is “extremely improbable.”

More than anything, though, it’s the secretiveness surrounding the allegedly sensational discovery that is causing the most agitation. “In Internet forums on the topic, moderators have had to warn people to temper their word choices,” says Michael Schudack, a paleontologist at Berlin’s Free University. For weeks Harald Meller, head of the Office for Monument Protection, released very little information about the find — ostensibly to keep hobby paleontologists away. Now, however, the accusation has been leveled that Meller, as an archeologist, is treading here on ground outside his field of expertise.

“We were only responsible for securing the tracks,” Meller says, defending his role. But Haubold suspects there may be another motive: “Mr. Meller wants another Nebra sky disk.”

 

Paleontologist Cajus Diedrich is responsible for the controversial discovery.
Martin Jehnichen

Paleontologist Cajus Diedrich is responsible for the controversial discovery.

Haubold is referring to a Bronze Age disk that brought Meller’s office fame in 1999. Also discovered in Saxony-Anhalt, the disk is known as the oldest depiction of the heavens worldwide. Haubold accuses the agency of looking to create a similar sensation with the fossilized tracks in Bernburg: “That’s not science, that’s just hype.”

Is it charlatanism on the one side, or injured vanity on the other? Diedrich claims his critics are just upset that they didn’t get their hands on the discovery first, and he feels he’s been attacked unfairly. “I don’t turn to colleagues for advice anymore,” he says, “because many of them don’t follow the scientific code of honor.”

Ultimately, that could help the researcher, whom even Haubold admits deserves “a lot of credit.” The appraisal of the Bernburg find is so controversial partly because — so far at least — no independent dinosaur tracks specialist has examined it.

In the meantime, Diedrich has submitted his data “to an international scientific journal” for review, but that step appears to be insufficient for quieting his critics.

 “With only tracks to go on, it’s very difficult to draw conclusions about a new dinosaur,” says Bonn University’s Sander. “There would have to be a skeleton.”

Perhaps Diedrich senses that, too. He’s already planning for his next coup. He wants to begin the search for evidence that supports his theory in Bernburg soon.

“The tracks continue further into the rock,” says Diedrich. “My hope is that the dinosaur who made it is at the end of the tracks.” But how probable is it that the creature would have done him the favor of dying right there?

source: http://www.spiegel.de/international/germany/0,1518,583116,00.html

RELATED SPIEGEL ONLINE LINKS

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view also the previous posts:

a) I dinosauri molto più vecchi di quanto si pensava (2) (Dinosaurier-spuren, Isochirotherium, Germany)

b) E 3 – I dinosauri molto più vecchi di quanto si pensava

and see also the comment (vedi anche il commento)

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ottobre 10, 2008 Posted by | - R. Dinosauri, 3 Triassico, Bl - Top posts, Europa, P - Evoluzione, P - Impronte, Paleontology / Paleontologia | , , , , , , , , , , , , , | 1 commento

I dinosauri molto più vecchi di quanto si pensava (2) (Dinosaurier-spuren, Isochirotherium, Germany)

Continuano le ricerche sulle “presunte” impronte di dinosauro ritrovate in agosto in Germania e che sposterebbero indietro di 15 milioni di anni la “nascita dei dinosauri”

Dinosaurier 15 Millionen Jahre älter als gedacht

Die Abdrücke in einem Tagebau beweisen es: Dinosaurier gab es bereits vor 243 Millionen Jahren – 15 Millionen Jahre früher als angenommen. Die bereits im Juni bei Bernburg in Sachsen-Anhalt freigelegten Spuren gelten als seltener und äußerst spektakulärer Fund.

Die Spuren beweisen, dass es bereits vor fast 245 Millionen Jahren Dinosaurier gab - 15 Millionen Jahren früher als bisher angenommen

Isochirotherium - Größe des Saurierabdrucks: Die Spuren beweisen, dass es bereits vor fast 245 Millionen Jahren Dinosaurier gab - 15 Millionen Jahren früher als bisher angenommen

Bernburg – “Das war schon eine Sensation”, schwärmte Cajus Diedrich, der Entdecker der Saurierspuren. “Uns war klar, dass das etwas Großes werden kann.” Der Forscher von der Universität Osnabrück hatte im Oktober 2007 gemeinsam mit Frank Trostheide vom Magdeburger Museum für Naturkunde in einem Kalksteinbruch bei Bernburg die Fährten von frühen Dinosauriern entdeckt.

Vom 9. Juni bis 4. Juli 2008 wurden in einem fünf Meter mächtigen Muschelkalkpaket fünf Schichten freigelegt und auf einer 50 mal 40 Meter großen Fläche die Spuren gesichert. Angesichts der großen Dichte von Fährten sprach Diedrich von einem spektakulären Fund. Inzwischen ist belegt, dass die Spuren zwischen 243,5 bis 243,9 Millionen Jahre alt sind. Bislang hatten Wissenschaftler angenommen, dass sich Dinosaurier erst im mittleren Trias vor 235 Millionen Jahren von anderen Archosauriern abgespaltet hatten.

Die Fährten könnten neue Erkenntnisse zur Evolution der ausgestorbenen Tiere liefern. “Woher die Saurier kamen, in dieser Beziehung herrschte bislang eine große Wissenslücke”, sagte Diedrich. “Aus der Mitteltrias gab es bislang weder Fährten- noch Skelettfunde von echten elefantenfüßigen Dinosauriern. Die Evolution muss also irgendwo dazwischen stattgefunden haben.” Mit den Funden von Bernburg sei nunmehr bewiesen, dass die Spezialisierung der Arten bereits in der Mitteltrias eingesetzt habe.

Die Dinos pressten die Fährten seinerzeit ins Watt eines sich vom heutigen Rhein bis nach Böhmen erstreckenden Binnenmeeres, dessen Boden sich durch Ebbe und Flut sowie unter wüstenartigen Bedingungen schnell verfestigte und die Spuren so konservierte. In seiner zwölfjährigen Forschung habe er andernorts bereits mehrere kleinere Spuren gefunden, sagte Diedrich, in Bernburg seien es jedoch ganze Spurenfolgen gewesen.

 

Als bemerkenswert bezeichnete er die 20 Meter lange Fährte eines primitiven Prosauropoden. Diedrich vermutet, dass sie von einer drei Meter langen, hochbeinigen Echse hinterlassen wurde, die einem Krokodil ähnelte. Diese Raubsaurierspur wird von einer Fährte eines elefantenfüßigen großen Dinos gekreuzt. “Ein einmaliger Fund”, meint Diedrich.

Neben den Fährten wurden unter anderem Knochen wie Rippen, Wirbelbögen und Sitzbeine gefunden. Laut Diedrich könnte die seltene Kombination von Fährten und Knochen eine neue Vorstellung von der Nahrungskette im Trias-Watt liefern.

Die ältesten bekannten Dinosaurierarten lebten vor mehr als 200 Millionen Jahren. Die meisten bewohnten Gebiete mit reicher Vegetation in der Nähe von Küsten und Binnengewässern. Sie waren an warmes, subtropisches Klima angepasst, konnten aber auch Kälteperioden überstehen.

Dinosaurier kamen in vielen verschiedenen Arten vor. Die kleinsten waren rund 30 Zentimeter, die größten 37 Meter lang. Manche ernährten sich von Pflanzen, andere von Fleisch und Aas. Die Ursachen für das Aussterben der Dinosaurier vor rund 65 Millionen Jahren sind bis heute noch nicht ganz geklärt. Wahrscheinlich ist, dass sich die hoch spezialisierten Tiere nicht an grundlegend veränderte Umweltbedingungen anpassen konnten. Die meisten Forscher gehen davon aus, dass der Einschlag eines Meteoriten, ein Vulkanausbruch oder beides die Umwelt über Jahre hinweg stark veränderten und so den Niedergang der Dinosaurier einleiteten.

 

hda/ddp/AP/dpa

link: http://www.spiegel.de/wissenschaft/natur/0,1518,581983,00.html (see also for additional photo)

DINOSAURIER: ÄLTER ALS GEDACHT

Fotostrecke starten: Klicken Sie auf ein Bild (7 Bilder)

see also previous post (link)

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Other links (news, In german)

Halle: 243 Millionen Jahre alte Dinosaurier-Spuren vorgestellt
ZEIT ONLINE – 21 ore fa
Rund 243 Millionen Jahre alte Dinosaurier-Spuren sind am Donnerstag in Halle der Öffentlichkeit vorgestellt worden. Der spektakuläre Fund, darunter eine 25
245 Millionen Jahre alte Saurierspuren entdeckt
MDR – 21 ore fa
Wissenschaftler haben bei Grabungen in einem Kalkstein-Tagebau bei Bernburg fast 245 Millionen Jahre alte Spuren von Dinosauriern entdeckt.
SPUREN IN SACHSEN-ANHALT Dinosaurier 15 Millionen Jahre älter als
Spiegel Online – 21 ore fa
Die Abdrücke in einem Tagebau beweisen es: Dinosaurier gab es bereits vor 243 Millionen Jahren – 15 Millionen Jahre früher als angenommen.
Sensationsfund in Sachsen-Anhalt:
Netzeitung – 22 ore fa
Ein Kalksteinbruch in Bernburg macht Experten euphorisch: Schlappe 15 Millionen Jahre weichen die dort gefundenen Spuren vom bisher angenommenen Alter ab.
243 Millionen Jahre alte Dinosaurier-Spuren vorgestellt
Mitteldeutsche Zeitung – 22 ore fa
Halle/dpa/ddp. Bei Grabungen in einem Kalkstein-Tagebau bei Bernburg in Sachsen-Anhalt haben Wissenschaftler fast 245 Millionen Jahre alte Spuren von

ottobre 3, 2008 Posted by | - R. Dinosauri, 3 Triassico, Bl - Top posts, Lang. - German, P - Impronte, P - Ritrovamenti fossili, Paleontology / Paleontologia | , , , , , , , , , , , , | 1 commento

2008-09-19 – Paleoecologia del tardo Triassico

Discussion on Palaeoecology of the Late Triassic Extinction Event in the SW UK

Posted on: Friday, 19 September 2008, 03:00 CDT

By Radley, Jonathan Twitchett, Richard J; Mander, Luke; Cope, John

see link:

http://www.redorbit.com/news/

settembre 20, 2008 Posted by | 3 Triassico, conferenze, Paleontology / Paleontologia | , , , , | Lascia un commento

E 3 – I dinosauri molto più vecchi di quanto si pensava

I dinosauri molto più vecchi di quanto si pensava

I dinosauri sono molto piu’ vecchi di quanto si pensasse: ne e’ convinto un gruppo di paleontologi della Sassonia-Anhalt, nell’Est della Germania, che hanno trovato tracce di un animale preistorico nato 15 milioni di anni prima di qualsiasi altro suo consimile conosciuto finora. I paleontologi hanno scoperto in una cava di calcare della regione i resti di un dinosauro esistito oltre 250 milioni di anni fa. Mai prima d’ora erano venute alla luce ossa cosi’ antiche di questi animali.

Per il momento, le autorita’ della regione non hanno confermato la scoperta, ma la comunita’ scientifica gia’ parla di un ritrovamento di “importanza sensazionale”.

Secondo la teoria corrente, i dinosauri si sarebbero evoluti dagli arcosauri circa 235 milioni di anni fa, cioe’ 15 milioni di anni dopo la nascita del dinosauro della Sassonia-Anhalt.

‘Sensational’ fossil illuminates birth of dinosaurs

Last Updated: 2:01pm BST 22/08/2008

An archaeological dig in central Germany has unearthed fossils which could be the oldest record of dinosaur life ever.

  • ‘Calamari killing field’ fossils found
  • Missing link feather fossils found in France
  • ‘Frog from Hell’ that ate baby dinosaurs

    The dinosaur find, at a quarry near the town of Bernburg 90 miles south-west of Berlin, appears to date from 250 million years ago.

  • Scientists previously believed that dinosaurs evolved from smaller reptilians around 235 million years ago.

    But the new find could radically redraw archaeologists’ understanding of the dawn of the Triassic age, and the birth of the dinosaur era.

    “This is a spectacular, unique achievement,” said regional archaeology chief Harald Meller, announcing the discovery.

    He said that the crucial remnants ­ believed to be fossils of bone fragments – had been secured, but the German authorities called on amateur enthusiasts to stay away from the site, for fear of damaging potential further finds.

    Other experts declared the dig of “sensational importance”.

    If confirmed, the find would add to a long list of landmark archaeological dinosaur discoveries in Germany, including the Archaeopteryx, which showed a link between dinosaurs and birds.

    It was discovered in southern German in the 19th century, helping to cement the reputation of Darwin’s theory of evolution.

    Sensationsfund von Bernburg Den Sauriern auf der Spur
    Mitteldeutsche Zeitung – 20 ago 2008
    von Hendrik Kranert und Lars Geipel, 20.08.08, 11:06h, aktualisiert 20.08.08, 11:08h Bernburg/MZ. In einem Kalkstein-Tagebau im Norden von Bernburg wurden
    Sensationsfund von Bernburg Debatte um Spur der Saurier
    Mitteldeutsche Zeitung – 20 ago 2008
    von Hendrik Kranert und Lars Geipel, 20.08.08, 22:17h, aktualisiert 20.08.08, 22:28h Bernburg/MZ. Nach dem Fund von Saurierspuren Anfang Juni in einem
    Forscher prüfen Alter von Saurierfährten
    sueddeutsche.de – 20 ago 2008
    Bernburg/Halle (dpa) – Nach einem Fund von Saurierfährten in einem Kalkstein-Tagebau in Bernburg (Sachsen-Anhalt) wollen Wissenschaftler nun das genaue
    Sensationelle Saurierspuren in Sachsen-Anhalt entdeckt
    net-tribune.de – 20 ago 2008
    Halle – Ein sensationeller Fund in Sachsen-Anhalt könnte die Geschichte der Dinosaurier revolutionieren. In einem Kalkstein-Tagebau bei Bernburg wurden

    settembre 19, 2008 Posted by | - R. Dinosauri, 3 Triassico, Europa, P - Ritrovamenti fossili, Paleontology / Paleontologia | , , , , , , | 2 commenti

    Tracce fossili di escavazione nel Triassico dell’Antartide

    Articolo tratto da www.hindu.com (link):

    Pre-dinosaur era burrows discovered in Antarctica

    New York (PTI): Paleontologists have discovered pre-dinosaur era burrows in Antarctica, which they claim were probably dug up by tetrapods — any land vertebrates with four legs — about 245 million years ago. The largest burrow is about 35 centimetres long and six centimetres wide — it was preserved when a flood washed sand into it.

    Though no animal remains were found inside the burrow casts, the hardened sediment in each burrow preserved a track made as the animals entered and exited, according to the paleontologists. “In addition, scratch marks from the animals’ initial excavation were apparent in some places. We have got evidence that these burrows were made by land-dwelling animals rather than crayfish,” Christian Sidor of Washington University, who led the team, said.

    Despite the absence of fossil bones, the burrows’ relatively small size prompted the US team to speculate that their owners might have been small lizardlike reptiles called Procolophonids or an early mammal relative called Thrinaxodon.

    giugno 9, 2008 Posted by | - Mammiferi, - Rettili, 3 Triassico, Antartide, P - Impronte, P - Ritrovamenti fossili, Paleontology / Paleontologia | , , , , , | Lascia un commento