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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

Annunci

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

2008-10-29 – Utah, USA: Ritrovati resti di piante fossili durante scavi (Plant fossils)

 Durante la costruzione di un parco industriale è stato trovato un sito con resti di Conifere risalente a 198 milioni di anni fa. L’area è tra l’altro vicina al Dinosaur Discovery Site dove otto anni fa sono stati scoperte migliaia di impronte di dinosauri. I riceracatori si stanno preparando a raccogliere i reperti che saranno donati a vari musei statali.

vedi pure: 2008-10-26 – Utah, USA: uno dei posti migliori per i dinosauri (world’s best spots for dinosaurs)

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Plant fossils found near construction site in S. Utah

They are the only flora fossils ever found from the early Jurassic Period in the Western U.S.

ST. GEORGE – Stone fossils of plants that once fueled dinosaurs as they roamed around southern Utah some 198 million years ago were unveiled Tuesday at a ceremony.
    They were discovered Friday during construction work on a new industrial park.
    The fossils of the prehistoric flora, mainly conifers, are the only ones ever found from the early Jurassic Period in the Western United States.
    The site sits next to the Dinosaur Discovery Site at Johnson Farm, where eight years ago thousands of dinosaur tracks were discovered; they are now protected as a city-owned museum.
    Now developers will work with scientists to preserve the site.
    “This plant site is extremely important to help us examine further the vegetation recovery of plant life during the mass extinction at the end of the Triassic Period,” said Utah State Paleontologist Jim Kirkland.
    Kirkland said the area where the plant fossils and tracks are found was once on a vast lake’s northern shore that attracted dinosaurs.
    Andrew Milner, paleontologist for St. George, said one of the plant species, Saintgeorgeia jensenii is named after the city and another has been named after him, Milnerites planus.
    Trapped in the sedimentary stone, brown juniperlike leaves can be recognized sprouting from stems. Fossilized pine cones also were found.
“They [developers] have been very cooperative,” Kirkland said. “Because it is on private property, they could have told us to get lost and sold everything on eBay.”
    Don DeBlieux, a paleontologist with Utah Geological Survey, said several scientists descended on the site Sunday and have been splitting open stones since.
    “It’s neat,” DeBlieux said. “We’re finding a lot of things we haven’t seen before.
    Scientific museums around the country are interested in the find and have requested some of the fossils.
    Kirkland said samples will be shipped to the Smithsonian Institution, the Museum of Natural History in New York City, the University of California Berkeley, the University of Utah and Brigham Young University, among others.
    mhavnes@sltrib.com

source: http://www.sltrib.com/news/ci_10842050

see also: 2008-10-26 – Utah, USA: uno dei posti migliori per i dinosauri (world’s best spots for dinosaurs)

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Other links:


Washington Post

Paleontologists sift Utah soil for plant fossils
The Associated Press – 1 ora fa
The spot is in a bare lot near the Virgin River, not far from the city’s Dinosaur Discovery Site at Johnson Farm, where dinosaur tracks were found eight years ago. Andrew Milner, the city’s paleontologist, said the property’s developers have agreed to
Plant fossils found near construction site in S. Utah Salt Lake Tribune
Crews sift St. George soil for plant fossils LocalNews8.com
e altri 52 articoli simili »

ottobre 29, 2008 Posted by | 2 Jurassic / Giurassico, America Northern, Curiosità, Italiano (riassunto), P - Paleobotanica, P - Ritrovamenti fossili, Paleontology / Paleontologia | , , , , , , , , , | Lascia un commento

2008-10-24 – UK: Riscoperto dopo 150 anni sito con resti fossili eccezionalmente preservati (exceptional fossil preservation)

In Gran Bretagna riscoperto dopo 150 anni un sito che aveva fornito numerosi eccezionali ritrovamenti di pescsi e calamari con resti di parti molli risalenti al Giurassico.
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From
October 24, 2008

 Jurassic treasure trove lost by Victorians found by Phil Wilby, fossil sleuth

Phil Wilby
 [Photo: Phil Wilby with a fossilised ammonite found at the site near Christian Malford]

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One of the world’s most valuable fossil beds has been rediscovered, having been forgotten during Victorian times. Fossils recovered near Christian Malford in Wiltshire caused a sensation when they were unearthed in 1840 because they were the first to include the flesh of Jurassic wildlife.

Phil Wilby, of the British Geological Survey, has now rediscovered the site and led the first dig there in more than 150 years. He hopes that freshly recovered fossils can help to explain why tens of thousands of animals died simultaneously in episodes repeated many times over about a million years.

Fossil hunters and academics flocked to the area in the 1840s and 1850s to dig out extraordinarily well-preserved specimens of fish and squid-like creatures. But despite its importance as an extremely rare source of fossilised soft tissues preserved along with hard bones and shells, the location of the site was lost.

None of the Victorians who visited the site, even leading researchers from universities and museums, recorded the precise place and, when digging ended, the location was forgotten.

source: http://www.timesonline.co.uk/tol/news/uk/science/article5003383.ece

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Original scientific article:

Volume 24 Issue 3, Pages 95 - 98

Geology Today

Geology Today – Volume 24 Issue 3, Pages 95 – 98

Preserving the unpreservable: a lost world rediscovered at Christian Malford, UK

Philip R. Wilby 1 , Keith Duff 2 , Kevin Page 3 & Susan Martin 1
 1 British Geological Survey, Keyworth, Nottingham, NG12 5GG, UK. p.wilby@bgs.ac.uk; smart@bgs.ac.uk   2 Department of Geology, University of Leicester, Bennett Building, University Road, Leicester, LE1 7RH, UK. kld17@leicester.ac.uk   3 School of Earth, Ocean and Environmental Sciences, University of Plymouth, Drake Circus, Plymouth, PL4 8AA, UK. kevin.page@plymouth.ac.uk
Copyright © 2008 Blackwell Publishing Ltd
ABSTRACT

The small village of Christian Malford, Wiltshire (UK) is known to palaeontologists the world over because of the chance discovery of an astonishing fossil bonanza in the mid-nineteenth century. Pits in the Jurassic Oxford Clay yielded thousands of specimens of exquisitely preserved ammonites, fish and crustaceans, but became most famous for squid-like cephalopods and belemnites (collectively termed coleoids) with fossilized soft-parts. The precise location of the find has remained obscure, until now, and a new attempt is underway to understand the ancient environment that triggered this unusual preservation.

Published Online: 6 May 2008

ottobre 24, 2008 Posted by | - Pesci / Fishes, 2 Jurassic / Giurassico, Articolo sc. di riferimento, Curiosità, Europa, Italiano (riassunto), P - Preservazione eccezionale, Paleontology / Paleontologia | , , , , , , , , , , , | Lascia un commento

2008-10-24 – Thailandia: nuovo sito con resti di Dinosauri giurassici (Thailand, Jurassic, Dinosaurs)

In Thailandia un contadino scopre nuovo sito con resti fossili di dinosauri (sauropodi e teropodi) datato 150 milioni di anni fa.

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Second big fossil site unearthed at Kalasin

A new site rich in dinosaur fossils has been found in Kalasin province, with some of the fossils estimated to be 150 million years old. The new site is the second fossil discovery in the area after the find at Phu Kum Khao.

The new discovery was made in tambon Din Chee in Kham Muang district near the Phu Phan mountain range.

The fossils were found on land owned by Seethan Saengsit, 62, who made the discovery while working on her land.

Thida Saneyamoon, the chief of the geological survey unit of the Mineral Resources Department, said an initial dig had turned up several types of dinosaur fossils – sauropods and theropods – which were estimated to have roamed the area at least 150 million years ago.

There are also a number of fossils of crocodiles and fish, also estimated to be 150 million years old.

The fossils are to undergo a thorough examination by officials from the department. Ms Thida said the newly discovered fossils would be kept at the Sirindhorn Museum in Sahatsakhan district in Kalasin, where a number of rare fossils of crocodiles and replica skeletons of dinosaurs found in the region have been put on display.

Decha Tantiyawarong, the governor of Kalasin, said he had been told by the Mineral Resources Department that more than 100 fossils had been found.

The discovery was the second in the province following the find at Phu Kum Khao, which has some of the largest fossil deposits in Southeast Asia.

The governor said he had ordered the area to be guarded around the clock to prevent people digging up more fossils to supply illegal fossil traders.

The province bans the removal of fossils from the area without permission.

Based on the new Paleontological Research Protection Act of 2008, effective in August, anyone caught exporting rare fossils without permission could be jailed for up to seven years, or face a fine of up to 700,000 baht, and those trading in fossils without a licence face a one-year prison term or a 100,000 baht fine.

Any fossil discoveries have to be reported to the authorities within seven days, and those wanting to trade in fossils need to obtain a licence.

Anyone in possession of fossils needs to inform the Mineral Resources Department, either in writing or verbally within one year – by Aug 9, 2009 – or face a fine of up to 10,000 baht.

source: http://www.bangkokpost.com/241008_News/24Oct2008_news16.php

ottobre 24, 2008 Posted by | - R. Dinosauri, - Teropodi, - uova / eggs, 2 Jurassic / Giurassico, Asia, Italiano (riassunto), P - Ritrovamenti fossili, Paleontology / Paleontologia | , , , , , , , , , , , , , , | Lascia un commento

2008-08-21 – Campo di caccia per belemniti (Belemnotheutis), Giurassico, Gran Bretagna

‘Calamari killing field’ fossils found in sea that covered middle England

By Paul Eccleston

Last Updated: 4:01pm BST 21/08/2008

 

 

Scientists have unearthed evidence of a Jurassic killing field in a sea that once covered a wide area of middle England.

  • Fish fossil is oldest to have ‘fun sex’
  • Dinosaur professor to lure tourists with fossils
  • Missing link fossil settles frog evolution debate

    Fossil evidence points to cataclysmic events which would have killed millions of fish and other soft-bodied marine creatures.

  • Complete specimen of the largely soft-bodied squid-like creature  Belemnotheutis clasping a fish in its arms; collected in the mid-nineteenth century

    Complete specimen of the largely soft-bodied squid-like creature Belemnotheutis clasping a fish in its arms; collected in the mid-nineteenth century

     In turbulent environmental conditions 160m years ago the waters may have been poisoned by a volcanic eruption or suddenly deprived of oxygen wiping out much of the sea life.

    Dramatic and newly discovered fossil images reveal how voracious squid-like creatures were lured to the area to feed on the huge numbers of dead fish. Some held prey in their tentacles at the very moment they also succumbed in the deadly waters.

    The scientists believe it developed into a predator-trap in which victims acted as a draw on new shoals entering the area before they were themselves overcome in a perpetual deadly cycle.

    The Jurassic Oxford Clay provided almost unique conditions for the preservation of ammonites, fish and crustaceans but became world famous for squid-like cephalopods and belemnites with fossilized soft-parts.

    There are only a handful of areas in the world where creatures have been preserved in this way.

    Soft-bodied creatures such as worms and jellyfish probably dominated marine ecosystems at the time but they rarely show up in the fossil record because they decompose and vanish. Much more is known about creatures with decay-resistant hard-parts, such as bones, teeth or shells.

    But in some areas – such as the rediscovered site in Wiltshire which the ancient sea once covered – the normal process of decay didn’t happen and outlines of anatomy – even soft flesh areas such as gut, muscle and eye – were perfectly preserved partly because of the chemical make-up of the sediment.

    The areas are known as Fossil Lagerstätten and provide a much more accurate picture of ancient ecosystems.

    The site – discovered by chance as the Great Western Railway was constructed in the 1840s – provided a fossil bonanza for palaeontologists.

    Many of the best fossils were removed and taken to London for safety but ironically were destroyed in German air raids a century later.

    Because of its rich resources the location of the site was jealously guarded by a local carpenter who was an amateur fossil hunter. He collected many of the samples but provided misleading information about the exact location of the site and took his secret to the grave.

    Over time the railways cuttings became overgrown and flooded and were eventually lost.

    But now they have been rediscovered by scientists from the British Geological Society (BGS) and their work will form part of The Fossil Detectives an eight-part series for BBC FOUR, funded by The Open University (OU) and produced by the BBC’s Natural History Unit, BBC TV series.

    In the programmes Dr Hermione Cockburn, an associate lecturer with the OU, leads a team of fossil experts and geologists around Britain looking for the best fossil treasures and mysteries.

    Celebrity fossil hunters such as Sir David Attenborough, musician and writer Alex James, and singer/songwriter Billy Bragg also make appearances.

    Prior to the new excavation it was unknown whether all of the fossil squid collected in the 1840s had come from one or more level but it showed for the first time that the squid were concentrated at several different levels proving that mass mortality events repeatedly hit the area killing vast numbers of the squid and fish.

    The prehistoric shallow sea covered an area from Lincolnshire to Dorset and was bordered by coastal swamps where dinosaurs would have roamed.

    Dr Phil Wilby of the BGS described the area as ‘a calamari killing field’.

    He said it would have been an unstable environment in which the bottom waters continually switched from being able to support life to becoming hostile to life with fluctuations in oxygen level a constant threat.

    “As a preservation site for soft-bodied creatures it is as good as it comes and is recognised by palaeontologists the world over. What we don’t yet know what triggered the preservation. It may be that there was a build up of phosphorous in the sediment and when the creatures died and sank into it the chemical structure was changed,” he said.

  • The Fossil Detectives is being shown on BBC Four beginning on Thursday August 21.
  • settembre 20, 2008 Posted by | - Molluschi, 2 Jurassic / Giurassico, Europa, P - Preservazione eccezionale, P - Ritrovamenti fossili, Paleontology / Paleontologia | , , , , , , , , , | 1 commento

    Un nuovo “giacimento” di dinosauri scoperto nello Utah

    Dal sito del National geographic (link)


    “Amazing” Dinosaur Trove Discovered in Utah



    Brian Handwerk
    for National Geographic News

    June 17, 2008

     

    Crowded with dinosaurs, petrified trees, and other prehistoric treasures, an ancient riverbed in Utah is surprising scientists.

    The discovery sheds new light on a Jurassic landscape dominated by dinosaur giants that lived 145 to 150 million years ago (prehistoric time line).


    In just three weeks of work on federal land near Hanksville, Utah, paleontologists say they unearthed at least two meat-eating dinosaurs, a probable Stegosaurus, and four sauropods—long necked, long-tailed plant-eaters that could reach 130 feet (40 meters) long, making them the largest animals ever to have walked the Earth.

    “So far [the paleontologists] have found not only scattered bones but partial and complete skeletons. It’s really amazing,” said Scott Foss, a paleontologist in the Bureau of Land Management’s (BLM’s) Salt Lake City office.

    Big Sexy Dinosaurs

    Some BLM employees and many locals had known that there were dinosaur bones to be found near Hanksville. But the recent dig led by scientists from the Burpee Museum of Natural History in Rockford, Illinois, was still a shocker.

    “Nobody anticipated the scale or the scope of what was there. Once they started excavating, they realized that the magnitude was far more than they had expected,” Foss said.

    “About two weeks ago they notified us that this was pretty big and we’d better come and take a look.”

    The site, now known as the Hanksville-Burpee Quarry, is part of the Morrison formation. “[The formation is] where all the big sexy dinosaurs that we grew up learning about are most commonly found,” Foss said.

    Matthew Bonnan, of Western Illinois University, said, “In the late Jurassic you had the largest animals that ever walked the Earth.

    “The sauropods sort of reached their zenith of size at this point,” added Bonnan, who had just returned from the dig site.

    (Related: “Giant Duck-Billed Dino Unearthed in Utah” [October 3, 2007].)


    Riverbed Graveyard Uncovered


    Though the Hanksville-Burpee Quarry today is high and dry, it appears to have once been at a bend in a large, long-gone river.


    A bar or other river feature likely collected the corpses of dinosaurs and other animals that died upstream and were washed down during high-water events over several centuries. The result is a logjam of fossilized bones.

    The site’s sandstone also encases freshwater clams, petrified trees, and other preserved matter. “There is potential that there could be burrows that contain fossil mammals. We have petrified logs—a whole group of things that I think are going to tell us something very detailed about this environment,” Bonnan said.

    (Related: “Ancient Mammal Relative Dug Burrows in Antarctica?” [June 9, 2008].)

    The late Jurassic has been studied intensively for more than a century, yet some key questions linger.

    “The big open question that remains is the environment in which the Morrison fauna and flora existed,” said Hans-Dieter Sues, associate director for research and collections at the Smithsonian’s National Museum of Natural History in Washington, D.C.

    Sues has received funding from the National Geographic Society’s Committee for Research and Exploration.

    Early geologists imagined the Morrison-formation region as a vast swamp, the imagined prime real estate for all those sauropods.

    “But later geologists argued that the Morrison was deposited in a dry environment with just some large bodies of water,” said Sues, who is not involved with the Hanksville-Burpee dig.

    New Look at Familiar Dinos?

    Whatever mysteries the new site may hold, it is unlikely to produce any new dinosaur species, Sues said.

    “Except for some really small dinosaurs—including possible bird relatives/precursors—or a good skeleton of the giant Brachiosaurus, there is going to be little that is newsworthy regarding Morrison dinosaurs,” he said.

    “The big discoveries to be made lie with other groups of Morrison animals, such as flying reptiles and mammals, which are still mostly known from very fragmentary remains.”

    But team member Bonnan hopes the Hanksville-Burpee will eventually rival Utah’s other major Jurassic fossil troves—Dinosaur National Monument and the Cleveland-Lloyd Dinosaur Quarry.

    “Even if we don’t find anything new in terms of species, we’re looking at old bones with new eyes and new technologies,” he said.

    “In the old days it was more about finding the ‘biggest, baddest, bestest’ dinosaurs, and a museum might have just cherry-picked those best specimens.

    “Now there is more interest in the fossil assemblage—what does it tell you about the environment?”

    The site will close for the season on Friday. But scientists are already anxiously awaiting the resumption of excavations next summer.

    “It will take years to understand the real potential, or how big this site really is,” BLM’s Foss said. “But there is something there worth taking a really good look at.”

    giugno 18, 2008 Posted by | - R. Dinosauri, - Sauropodi b, 2 Jurassic / Giurassico, America Northern, P - Ritrovamenti fossili, Paleontology / Paleontologia | , , , , , , , , | Lascia un commento