Paleonews

Il blog dedicato ai Paleontologi !!!!

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

2008-10-14 – Canada: memorandum per proteggere i “McAbee fossil beds”

Le autorità canadesi si stanno muovendo per proteggere i siti del McAbee fossil beds (Eocene) e limitarne il saccheggio, anche se per ora è stato emanato soltanto un “memorandum” che impone di consegnare agli scienziati i reperti fossili più significativi.

vedi pure: 2008-10-12 – British Columbia, Canada: danneggiato sito dell’Eocene (fossil site damaged)

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B.C. government moves to protect 50-million-year-old fossil beds

Vancouver Sun – Published: Thursday, October 23, 2008

BRITISH COLUMBIA – The B.C. government announced Thursday it has signed a memorandum of understanding aimed at protecting globally significant fossil beds between Cache Creek and Kamloops.

Agriculture and Lands Minister Stan Hagen said the memorandum applies to the McAbee fossil beds dating back about 50 million years to the Eocene era. The site has already provided at least 23 new species of insects and four new species of plants with the potential for more to be discovered, he said.

The announcement immediately drew criticism for not going far enough.

Bruce Archibald, a post-doctoral fellow at Simon Fraser University who has done extensive research on the McAbee fossil beds, called for an “immediate stop-work order” on mineral claims at the site followed by the fossil beds being declared a protected heritage site.

The memorandum is “clearly insufficient in protecting this paleontological treasure, and does not yet represent real progress,” said Archibald, among five paleontologists who wrote a letter in 2007 outlining their concerns.

Richard Hebda, curator of botany and earth history at the Royal B.C. Museum, described the memorandum as a “really good start.” It applies to one mineral tenure for now, but the province will soon look at the scientific importance of other tenures in the area, he said.

The memorandum requires that significant fossils found on the site will be handed over to the province for study.

lpynn@vancouversun.com

© Vancouver Sun 2008

see also: 2008-10-12 – British Columbia, Canada: danneggiato sito dell’Eocene (fossil site damaged)

ottobre 24, 2008 Posted by | 6 Eocene, America Northern, Commercio illegale, Italiano (riassunto), P - Geositi, P - Ritrovamenti fossili, Paleontology / Paleontologia | , , , , , , , , | Lascia un commento

2008-10-22 – Proliferazione di organismi produttori di magnetite durante il “massimo termico del Paleocene-Eocene” (“Magnetic Death Star” fossil)

Studi geobiologici su microcristalli “giganti” di magnetite di origine biologica consentono nuove considerazioni sul “massimo termico del Paleocene-Eocene”.

Gli autori dello studio sostengono infatti che lo sviluppo di una spessa zona subossica con un elevata disponibilità di ferro bio-assilmilabile (prodottosi in seguito ai drammatici cambiamenti climatici e di pattern sedimentari dovuti a un forte riscaldamento globale) condusse alla diversificazione di organismi (anche eucarioti) produttori di magnetite.

N.B. vedi il filmato del cluster di cristalli ripreso al microscopio elettronico (Supporting Information)

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Geobiologists Discover Unique ‘Magnetic Death Star’ Fossil

 General Science / Archaeology & Fossils

Geobiologists Discover Unique 'Magnetic Death Star' Fossil

          (PhysOrg.com) — An international team of scientists has discovered microscopic, magnetic fossils resembling spears and spindles, unlike anything previously seen, among sediment layers deposited during an ancient global-warming event along the Atlantic coastal plain of the United States.

The researchers, led by geobiologists from the California Institute of Technology and McGill University, describe the findings in a paper published online this week in the Proceedings of the National Academy of Sciences (PNAS).
Fifty-five million years ago, Earth warmed by more than 9 degrees Fahrenheit after huge amounts of carbon entered the atmosphere over a period of just a few thousand years. Although this ancient global-warming episode, known as the Paleocene-Eocene Thermal Maximum (PETM), remains incompletely explained, it might offer analogies for possible global warming in the future.

Perhaps in response to the environmental stress of the PETM, many land mammals in North America became dwarfed. Almost half of the common sea bottom-dwelling microorganisms known as foraminifera became extinct in newly warmer waters that were incapable of carrying the levels of dissolved oxygen for which they were adapted.

“Imagine our surprise to discover not only a fossil bloom of bacteria that make iron-oxide magnets within their cells, but also an entirely unknown set of organisms that grew magnetic crystals to giant sizes,” said Caltech postdoctoral scholar Timothy Raub, who collected the samples from an International Ocean Drilling Program drill-core storehouse at Rutgers University in New Jersey.

A typical “giant” spearhead-shaped crystal is only about four microns long, which means that hundreds would fit on the period at the end of this sentence. However, the crystals found recently are eight times larger than the previous world record for the largest bacterial iron-oxide crystal.

According to Dirk Schumann, a geologist and electron microscopist at McGill University and lead author of the study, “It was easy to focus on the thousands of other bacterial fossils, but these single, unusual crystals kept appearing in the background. It soon became evident that they were everywhere.”

In addition to their unusually large sizes, the magnetic crystals occur in a surprising array of shapes. For example, the spearhead-like crystals have a six-sided “stalk” at one end, a bulbous middle, and a sharp, tapered tip at the other end. Once reaching a certain size, spearhead crystals grow longer but not wider, a directed growth pattern that is characteristic of most higher biological organisms.

The spearhead magnetic crystals compose a minor fraction of all of the iron-oxide crystals in the PETM clay layer. Most of the crystals have smaller sizes and special shapes, which indicate that they are fossils of magnetotactic bacteria. This group of microorganisms, long studied at Caltech by study coauthor Joseph Kirschvink, the Nico and Marilyn Van Wingen Professor of Geobiology, use magnets to orient themselves within Earth’s magnetic field, and proliferate in oxygen-poor water.

Spearheads are not, however, the rarest fossil type in the deposit. That honor belongs to a spherical cluster of spearheads informally dubbed the “Magnetic Death Star” by the researchers. The Magnetic Death Star may have preserved the crystals as they occurred in their original biological structure.

The researchers could not find a similar-shaped organism anywhere in the paleontological annals. They hypothesize that it may have been a single-celled eukaryote that evolved for the first time during the PETM and was outcompeted once the strange climate conditions of that time diminished. Alternatively, it may still exist today in a currently undiscovered location.

“The continental shelf of the mid-Atlantic states during the PETM must have been very iron-rich, much like the Amazon shelf today,” notes study coauthor Robert Kopp of Princeton University, who first started working on the project while a graduate student at Caltech. “These fossils may be telling a story of radical environmental transformation: imagine a river like the Amazon flowing at least occasionally where the Potomac is today.”

  Click here to enlarge image

The paper, “Gigantism in unique biogenic magnetite at the Paleocene-Eocene Thermal Maximum,” will appear in the early online issue of PNAS the week of October 20. The Caltech work was supported by the NASA Exobiology program.
Provided by California Institute of Technology

souurce: http://www.physorg.com/news143818456.html

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Original article:

Gigantism in unique biogenic magnetite at the Paleocene–Eocene Thermal Maximum

Dirk Schumann et al.

PNAS doi:10.1073/pnas.0803634105

 Abstract

We report the discovery of exceptionally large biogenic magnetite crystals in clay-rich sediments spanning the Paleocene–Eocene Thermal Maximum (PETM) in a borehole at Ancora, NJ. Aside from previously described abundant bacterial magnetofossils, electron microscopy reveals novel spearhead-like and spindle-like magnetite up to 4 μm long and hexaoctahedral prisms up to 1.4 μm long. Similar to magnetite produced by magnetotactic bacteria, these single-crystal particles exhibit chemical composition, lattice perfection, and oxygen isotopes consistent with an aquatic origin. Electron holography indicates single-domain magnetization despite their large crystal size. We suggest that the development of a thick suboxic zone with high iron bioavailability—a product of dramatic changes in weathering and sedimentation patterns driven by severe global warming—drove diversification of magnetite-forming organisms, likely including eukaryotes.

Abstract  -  Full Text (PDF)  -  Supporting Information

ottobre 22, 2008 Posted by | 6 Eocene, 7 Paleocene, G - Geobiology, Geology - Geologia, Multimedia, P - Extinctions, P - Paleoclimatologia, Paleontology / Paleontologia, X - PNAS | , , , , , , , | Lascia un commento

2008-10-15 – Texas, USA: Rifugio per mammiferi fossili (Eocene, mammals, Diablomomys dalquesti)

Nuovi resti fossili testimoniano la permanenza di mammiferi in Texas nell Eocene in un periodo di “stress climatico”

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New Fossil Reveals Primates Lingered in Texas; Climate Provided Refuge for Diminishing Population

October 13, 2008

E-mail this article

AUSTIN, Texas — More than 40 million years ago, primates preferred Texas to northern climates that were significantly cooling, according to new fossil evidence discovered by Chris Kirk, physical anthropologist at The University of Texas at Austin.

 

Kirk and Blythe Williams from Duke University have discovered Diablomomys dalquesti, a new genus and species of primate that dates to 44-43 million years ago when tropical forests and active volcanoes covered west Texas.

The researchers have published their discovery in the Journal of Human Evolution article, “New Uintan Primates from Texas and their Implications for North American Patterns of Species Richness during the Eocene.”

During the early part of the Eocene epoch, primates were common in the tropical forests that covered most of North America. Over time, however, climatic cooling caused a dramatic decline in the abundance and diversity of North American primates. By the end of the Eocene, primates and most tropical species had almost disappeared from North America.

Kirk’s discovery of late middle Eocene (Uintan) primates at the Devil’s Graveyard Formation in Southwest Texas reveals new information about how North American primates evolved during this period of faunal (animal) reorganization.

“After several years of collecting new fossils, reviewing Texas’ primate community and comparing it to other places in North America, we found a much more diverse group of primate species in Texas than we expected,” Kirk said. “It seems that primates stuck around in Texas much longer than many other parts of the continent because the climate stayed warm for a longer period of time. While primate diversity was falling off precipitously in places like Utah and Wyoming during the late middle Eocene, west Texas provided a humid, tropical refuge for primates and other arboreal (tree-inhabiting) animals.”

The anthropologists named the new primate Diablomomys dalquesti, combining “Diablo” to represent the Devil’s Graveyard Formation (sand- and mudstones near Big Bend National Park) with Omomys, a related fossil genus. The dalquesti species name honors Walter and Rose Dalquest, who donated the land on which the fossil was collected (Midwestern State University’s ‘Dalquest Research Site’). Walter was a Texas paleontologist and distinguished biology professor at Midwestern State University in Wichita Falls until his death in 2000.

For more information, contact: Christian Clarke Casarez, Office of Public Affairs, 512-471-4945; Chris Kirk, assistant professor, Department of Anthropology, 512-471-0056 (office), 512-636-2634 (cell).

  Related Stories:

source: http://www.utexas.edu/news/2008/10/13/fossil_primates/

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update 2008-10-21 11:23 Italy


Environment News Service
Fossil Reveals Ancient Primates Took Refuge in Texas
Environment News Service - 59 minuti fa
AUSTIN, Texas, October 20, 2008 (ENS) – More than 43 million years ago, when tropical forests and active volcanoes covered west Texas, primates chose to

ottobre 15, 2008 Posted by | - Mammiferi, - Primati, 6 Eocene, America Northern, Lang. - Italiano, P - Ritrovamenti fossili, Paleontology / Paleontologia | , , , , , , , , , , , , | Lascia un commento

2008-10-12 – British Columbia, Canada: danneggiato sito dell’Eocene (fossil site damaged)

Fossil hunters run amok and the B.C. government sits idle

Stephen Hume, Vancouver Sun

Published: Friday, October 10, 2008

A fossil bed of global importance is being irreparably damaged by commercial fossil hunters operating with provincial government approval, say leading scientists.

And scientists’ letters to a series of cabinet ministers and senior bureaucrats show that although the province is finally seeking someone to monitor the site, it has been aware of the concerns for almost a decade.

The operations take place under provincial regulations.

One letter likened what’s been going on to “wrapping fish in the Dead Sea Scrolls.”

The McAbee site between Kamloops and Cache Creek is a 51-million-year-old lake bed that yields exquisitely preserved fossils from the early Eocene epoch. Scientists say it holds answers critical to our present-day understanding of how plants and animals adapt to rapid climate change.

The Eocene is known for its diversity of large and exotic mammals, among them a carnivorous ungulate. The scientific value of the McAbee site, however, is its vast array of lesser-known plant, insect, fish and bird species that flourished when the world was much warmer and palms grew in what’s now Alaska.

Tree leaves, flowers and pollen fell into the water, sank into the mud along with now-extinct insect and fish species and, layer by layer over millions of years, created a stunning fossilized record of a lost world that may hold information crucial to survival in ours.

It’s the diversity of the site that permits scientists to collect large assemblages of fossil specimens preserved in vertical layers of shale — the site’s “stratigraphy” — and enables them to study their evolution over long periods of time.

The Eocene is vital for scientific study because it was in this time that the evolutionary ancestors of many modern animals, insects and plants first appeared.

But five of Canada’s leading paleontologists have written to the provincial government protesting that the stratigraphic integrity of the site is being destroyed by the use of heavy equipment in the hunt for individual specimens prized for commercial sale.

“We are writing to you to express our concern that an important British Columbia heritage site is currently being dismantled and sold to the highest bidder,” the scientists said in a March 2, 2007 letter to Charlie Wyse, the Liberal MLA for Cariboo South.

“This important fossil locality is currently under mineral claim by fossil dealers, has been extensively worked, and is being rapidly destroyed.”

The letter, one of a number going back as far as 2002, advised the province that individual fossil specimens from the McAbee site were for sale on the Internet.

The letter was signed by James Haggart, chair of the B.C. Paleontological Alliance, Rolf Mathewes of Simon Fraser University, James Basinger at the University of Saskatchewan, David Greenwood at Brandon University and Bruce Archibald, a PhD candidate at Harvard University.

Archibald, now a post-doctoral fellow at Simon Fraser University, has done extensive research on the McAbee fossils.

He wrote again on Sept. 11, 2008, this time to Stan Hagen, minister of agriculture and lands, to inform the government that he had just visited the McAbee site.

“I was absolutely shocked to see the amount of new destruction present,” Archibald wrote. “In fact, the richest beds containing the most finely preserved and most diverse fossils are now completely destroyed, or very nearly so. It is quite clear that degradation of the site has greatly accelerated since I visited it last year before the claimholders signed the current agreement with your ministry supposedly defining their appropriate stewardship of the site.”

shume@islandnet.com

© The Vancouver Sun 2008

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Additional info:

Site description: http://www.fossilmuseum.net/Fossil_Sites/mcabee.htm

Scientific info: by Heidi Henderson blog

Fossil tour: http://www.dll-fossils.com/

Fossils for sale: http://www.fossilscapes.com/plants/plantfossils1.htm

ottobre 12, 2008 Posted by | 6 Eocene, America Northern, Commercio illegale, P - Geositi, P - Paleobotanica, Paleontology / Paleontologia | , , , , , , , , | 1 commento

2008-09-27 Trovato fossile di “Super-Papera” – Dasornis (GBR)

Fossil of 15ft duck in clay

DISCOVERY

The skull of a giant duck which had sharp teeth, a 15ft wingspan has been found in southern England.

The fossil of the Dasornis, which cruised seas covering the South East 50 million years ago, was buried in clay at the Isle of Sheppey, Kent.

Their wingspan – the length of a family car – meant they could cover huge distances. Latest research suggests the closest living relative of the bird is the humble duck.

Expert Gerald Mayr told journal Palaeontology the skull is “one of the best found”. It is now on show in Germany.

http://www.mirror.co.uk/news/top-stories/2008/09/27/fossil-of-15ft-duck-in-clay-115875-20755334/

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IT IS A PLANE? NO, IT’S A 16FT GOOSE…

IT WAS the Mother Goose of all time – a bird with a 16ft wing span which soared over southern England 50million years ago.

The bird had a 16 foot wing span and soared over the wetlands of prehistoric southern England

The bird had a 16 foot wing span and soared over the wetlands of prehistoric southern England Scientists discovered this Dasornis fossil skull buried in clay on the Isle of Sheppey Now a well-preserved fossil skull of the giant bird, a dasornis, has been found on the Isle of Sheppey off the north Kent coast, scientists announced yesterday.Dasornis was in many ways similar to the modern albatross, but its closest cousins are ducks and geese. Scientists discovered this Dasornis fossil skull buried in clay on the Isle of Sheppey

Dr Gerald Mayr, who described the discovery in the journal Palaeontology, said: “Imagine a bird like an ocean-going goose, almost the size of a small plane.

“These were pretty bizarre animals, but perhaps the strangest thing about them is that they had sharp, tooth-like projections along the cutting edges of the beak.

“No living birds have true teeth because their distant ancestors did away with them more than 100million years ago, probably to save weight and make flying easier.

“But the bony-toothed birds, like dasornis, are unique among birds in that they re-invented tooth-like structures.”

He added: “These birds probably skimmed across the surface of the sea, snapping up fish and squid.

“With only an ordinary beak, these would have been difficult to keep hold of, and the pseudo-teeth evolved to prevent meals slipping away.”

http://www.express.co.uk/posts/view/63421/It-is-a-plane-No-it-s-a-16ft-goose-

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A SKULL OF THE GIANT BONY-TOOTHED BIRD DASORNIS (AVES: PELAGORNITHIDAE) FROM THE LOWER EOCENE OF THE ISLE OF SHEPPEY
Plane-sized bird
Sydney Morning Herald - 1 ora fa
A STUDY has revealed a bird that swooped over waters covering what is now south-east England had wings that spanned five metres tip to tip and bony teeth to
Bird the size of plane found near London
ABC Online - 17 ore fa
Scientists have revealed the existence of a huge bird with bony teeth and wings spanning five metres, that once swooped over the wetlands of southern
When giant prehistoric geese roamed the earth
MSNBC - 18 ore fa
By Andrea Thompson Scientists have found a new huge and well-preserved fossil of a goose and duck relative that swam around what is now England 50 million
Lord of the skies was a giant goose with a beak full of crocodile
Times Online - 19 ore fa
A giant geese-like bird that was the size of a light aircraft and had a beak like a crocodile’s jaws has been found to have soared above Britain 50 million
Mother Of A Goose! Giant Ocean-going Geese With Bony-teeth Once
Science Daily (press release) - 20 ore fa
ScienceDaily (Sep. 26, 2008) — A 50 million year old skull reveals that huge birds with a 5 metre wingspan once skimmed across the waters that covered what
Mega-bird had a five-metre wingspan… and teeth
AFP - 21 ore fa
PARIS (AFP) — A bird that swooped over the waters covering what is now southeast England had wings that spanned five metres (16.25 feet) tip to tip and had
Giant prehistoric geese the size of small plane
Telegraph.co.uk - 21 ore fa
By Richard Alleyne Giant prehistoric geese the size of small aircraft once flew over Britain, scientists have discovered. Dasornis, which had a 16 ft
Fossil of 15ft duck in clay
Mirror.co.uk - 11 ore fa
The skull of a giant duck which had sharp teeth, a 15ft wingspan has been found in southern England. The fossil of the Dasornis, which cruised seas covering
Don’t ruck with this duck
The Sun - 15 ore fa
GIANT ducks sporting teeth and a 15ft wingspan once flew over Britain, experts said yesterday. One of the best-ever fossilised skulls of the creatures
One more terror for ancient ocean fish: monster ducks
World Science - 18 ore fa
As if the little fish of the ancient seas didn’t have enough terrifying predators to deal with, they also had to contend with duck-like birds,
Big bird: Experts unveil skull of giant duck with teeth and the
Daily Mail - 21 ore fa
By Daily Mail Reporter Instead of the fluffy little creatures seen today, these big birds boasted ‘teeth’, a 16ft wingspan and once flew over Britain.

 

GERALD MAYR
Forschungsinstitut Senckenberg, Sektion Ornithologie, Senckenberganlage 25, D-60325 Frankfurt am Main, Germany; e-mail: Gerald.Mayr@senckenberg.de
Copyright © The Palaeontological Association, 2008
KEYWORDS
Fossil birds • bony-toothed birds • Dasornis emuinus • taxonomy • evolution • Eocene

ABSTRACT

Abstract: The first substantial skull of a very large Paleogene bony-toothed bird (Pelagornithidae) is described from the Lower Eocene London Clay of the Isle of Sheppey in England. The specimen is assigned to Dasornis emuinus (Bowerbank), based on a taxonomic revision of the large London Clay Pelagornithidae. Very large bony-toothed birds from the London Clay were known previously from fragmentary remains of non-comparable skeletal elements only, and Dasornis londinensis Owen, Argillornis emuinus (Bowerbank), A. longipennis Owen, and Neptuniavis miranda Harrison and Walker are considered junior synonyms of D. emuinus. The new specimen allows a definitive assignment of Dasornis to the Pelagornithidae and documents that this taxon closely resembles other bony-toothed birds in cranial morphology. It is hypothesized that giant size (i.e. a wingspan above 4 m) evolved only once within Pelagornithidae and that Dasornis emuinus is the sister taxon of the giant Neogene bony-toothed birds, which share a derived wing morphology.

Abstract References  |  Full Text: HTML, PDF (528k) | Related Articles | Citation Tracking

 

settembre 27, 2008 Posted by | - Uccelli / Birds, 6 Eocene, Articolo sc. di riferimento, Europa, FREE ACCESS, P - Ritrovamenti fossili, Paleontology / Paleontologia | , , , , , , , , , , , , , , | Lascia un commento

I pesci fossili di Bolca forniscono nuovi esempi di asimmetria [Amphistium, Heteronectes, Pleuronectiformes]


I pesci fossili di Bolca forniscono nuovi esempi di asimmetria[vedi numero di Settembre 2008 di "Le Scienze"]


Links:

http://www.telegraph.co.uk/earth/main.jhtml?view=DETAILS&grid=&xml=/earth/2008/07/09/sciflat109.xml

Video from Youtube:

http://www.youtube.com/watch?v=qSYl4aMe0BE

Links from Nature.com 

1. The evolutionary origin of flatfish asymmetry

Matt Friedman

SUMMARY: All adult flatfishes (Pleuronectiformes), including the gastronomically familiar plaice, sole, turbot and halibut, have highly asymmetrical skulls, with both eyes placed on one side of the head.

CONTEXT: …Naturhistorisches Museum, Vienna (NHMW). Total length is 142 mm; standard length is 111 mm. Horizon and locality. Bolca, possibly Monte Postale locality, northern Italy. Lower Eocene (Ypresian; SBZ11). Diagnosis. Stem pleuronectiform…

Nature 454, 209 – 212 (10 Jul 2008), doi: 10.1038/nature07108, Letter

2. The eyes have it

Daniel Cressey

SUMMARY: Fossilized flatfish settle evolutionary conundrum.

CONTEXT: …I first noticed the fossil, it was sitting unidentified in a drawer of indeterminate fossil fish pieces from Monte Bolca [in Italy],” he says. “And believe me, it didn t look like much at the time it was an incomplete specimen…

Nature News (09 Jul 2008), doi: 10.1038/news.2008.946, News

3. Palaeontology: Squint of the fossil flatfish

Philippe Janvier

SUMMARY: Evolutionary biologists have floundered when trying to explain how the asymmetrical head of flatfishes came about. ‘Gradually’ is the answer arising from exquisite studies of 45-million-year-old

CONTEXT: …(which has been known for a long time). The specimens all come from the exceptional fossil-fish locality of Bolca, Italy, and were once regarded as possible flatfish relatives on the basis of their postcranial skeleton. However, this…

Nature 454, 169 – 170 (09 Jul 2008), doi: 10.1038/454169a, News and Views

settembre 23, 2008 Posted by | - Italia, - Pesci / Fishes, 6 Eocene, Articolo sc. di riferimento, P - Evoluzione, P - Ritrovamenti fossili, Paleontology / Paleontologia, Video | , , , , , , , , , , , , , , | Lascia un commento

   

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