Paleonews

Il blog dedicato ai Paleontologi !!!!

2009-07-05 – Indonesian elephant fossil

Indonesian elephant fossil opens window to past

By NINIEK KARMINI – Jun 22, 2009

Indonesia Prehistoric Elephant

Scientists arrange the bones of an estimated 200,000 year-old giant elephant at Geology Museum in Bandung, West Java, Indonesia, Thursday, June 18, 2009. Indonesian scientists are reconstructing the largest, most complete skeleton of an ancient elephant ever found in the tropics, a finding that may offer new clues into the largely mysterious origins of its modern Asian cousin. Based on the fossil, the ancient elephant stood four meters (13-feet) tall, was five meters (16-feet) long and weighed more than 10 tons, considerably larger than the great Asian mammals now on Earth. (AP Photo/Dita Alangkara)

 BANDUNG, Indonesia (AP) — Indonesian scientists are reconstructing the largest, most complete skeleton of a prehistoric giant elephant ever found in the tropics, a finding that may offer new clues into the largely mysterious origins of its modern Asian cousin.

The prehistoric elephant is believed to have been submerged in quicksand shortly after dying on a riverbed in Java around 200,000 years ago. Its bones — almost perfectly preserved — were discovered by chance in March when an old sand quarry collapsed during monsoon rains.

The animal stood four meters (13-feet) tall, five meters (16-feet) long and weighed more than 10 tons — closer in size to the woolly mammoth of the same period than to the great Asian mammals now on Earth.

Animal fossils are rare in the humid, hot climate of the equator because decomposition occurs extremely quickly.

Following a monthlong excavation, a team of seven paleontologists from the Geology Museum in Bandung, West Java, set the bones in plaster for the trip back to their office where they will be laboriously pieced back together.

“We believe from the shape of its teeth that it was a very primitive elephant,” but little else has been verified, said paleontologist Fachroel Aziz, who is heading a 12-strong skeletal reconstruction team.

Scientists agree it is the first time an entire prehistoric elephant skeleton has been unearthed since vertebrate fossil findings began to be recorded in Indonesia in 1863.

“It is very uncommon to discover a fossil like this in a tropical region like Indonesia,” said Edi Sunardi, an independent expert at Indonesia’s Pajajaran University in Bandung, West Java. “It apparently was covered by volcanic sediment that protected it from high temperatures, erosion and decay.”

The next challenge will be removing the delicate bones from their molds and joining them into a stable, upright structure, a process that experts said is already being hampered by a lack of funding, inadequate tools and poor expertise.

Indonesia, an emerging and impoverished democracy of 235 million people, cannot afford to allocate more than a token sum to its aging museums, even for projects that have the potential to advance knowledge about the origin of key native species.

Gert van den Berg, a researcher at Australia’s Wollongong University who helped dig up the skeleton, said tests are under way to determine its precise age and species, and that they will help provide details “about when the modern elephants evolved into what they are now.”

About 2,000 old elephant remains have been found across the island nation over the past 150 years, but never in such good condition, Aziz said.

“We want to exhibit it publicly because this is a spectacular discovery,” he said.

 The Associated Press

luglio 5, 2009 Posted by | - Mammiferi, An. Vertebrates, Asia, Cenozoic, P - Ritrovamenti fossili, Paleontology / Paleontologia | , , , | Lascia un commento

2009-07-04 – Myanmar: nuovo Primate fossile (new fossil Primate)

New Fossil Primate Suggests Common Asian Ancestor, Challenges Primates Such As ‘Ida’

ScienceDaily (July 1, 2009) — According to new research published online in the Proceedings of the Royal Society B (Biological Sciences) on July 1, 2009, a new fossil primate from Myanmar (previously known as Burma) suggests that the common ancestor of humans, monkeys and apes evolved from primates in Asia, not Africa as many researchers believe.

The discovery of this new fossil primate from Myanmar (previously known as Burma) suggests that the common ancestor of humans, monkeys and apes evolved from primates in Asia, not Africa as many researchers believe. (Credit: Mark A. Klingler/Carnegie Museum of Natural History)

The discovery of this new fossil primate from Myanmar (previously known as Burma) suggests that the common ancestor of humans, monkeys and apes evolved from primates in Asia, not Africa as many researchers believe. (Credit: Mark A. Klingler/Carnegie Museum of Natural History)

A major focus of recent paleoanthropological research has been to establish the origin of anthropoid primates (monkeys, apes and humans) from earlier and more primitive primates known as prosimians (lemurs, tarsiers and their extinct relatives). Prior to recent discoveries in China, Thailand, and Myanmar, most scientists believed that anthropoids originated in Africa. Earlier this year, the discovery of the fossil primate skeleton known as “Ida” from the Messel oil shale pit in Germany led some scientists to suggest that anthropoid primates evolved from lemur-like ancestors known as adapiforms.

According to Dr. Chris Beard–– a paleontologist at Carnegie Museum of Natural History in Pittsburgh, Pennsylvania and a member of the international team of researchers behind the Myanmar anthropoid findings––the new primate, Ganlea megacanina, shows that early anthropoids originated in Asia rather than Africa. These early Asian anthropoids differed radically from adapiforms like Ida, indicating that Ida is more closely related to modern lemurs than it is to monkeys, apes and humans.

The 38-million-year-old Ganlea megacanina fossils, excavated at multiple sites in central Myanmar, belong to a new genus and species. The name of the new species refers to a small village, Ganle, near the original site where the fossils were found, and the greatly enlarged canine teeth that distinguish the animal from closely related primates. Heavy dental abrasion indicates that Ganlea megacanina used its enlarged canine teeth to pry open the hard exteriors of tough tropical fruits in order to extract the nutritious seeds contained inside.

“This unusual type of feeding adaptation has never been documented among prosimian primates, but is characteristic of modern South American saki monkeys that inhabit the Amazon Basin,” says Dr. Beard. “Ganlea shows that early Asian anthropoids had already assumed the modern ecological role of modern monkeys 38 million years ago.”

Ganlea and its closest relatives belong to an extinct family of Asian anthropoid primates known as the Amphipithecidae. Two other amphipithecids, Pondaungia and Myanmarpithecus, were previously discovered in Myanmar, while a third, named Siamopithecus, had been found in Thailand. A detailed analysis of their evolutionary relationships shows that amphipithecids are closely related to living anthropoids and that all of the Burmese amphipithecids evolved from a single common ancestor. Some scientists had previously argued that amphipithecids were not anthropoids at all, being more closely related to the lemur-like adapiforms.

The discovery of Ganlea strongly supports the idea that amphipithecids are anthropoids, because adapiforms never evolved the features that are necessary to become specialized seed predators. Indeed, all of the Burmese amphipithecids appear to have been specialized seed predators, filling the same ecological niche occupied by modern pitheciine monkeys in the Amazon Basin of South America. During the Eocene when Ganlea and other amphipithecids were living in Myanmar, they inhabited a tropical floodplain that was very similar to the environment of the modern Amazon Basin.

Fossils of Ganlea megacanina were first discovered in Myanmar in December 2005. The fieldwork is a long-term collaboration by scientists from several institutions in Myanmar; as well as the University of Poitiers and the University of Montpellier in France; Carnegie Museum of Natural History in Pittsburgh, PA; and the Department of Mineral Resources in Bangkok, Thailand. Funding was provided by the U.S. National Science Foundation and the Centre National de la Recherche Scientifique in France.


Adapted from materials provided by Carnegie Museum of Natural History.
Source: http://www.sciencedaily.com/releases/2009/06/090630202125.htm

luglio 4, 2009 Posted by | 1 | , , | Lascia un commento

2009-05-27 – Peru`: scoperto bradipo fossile (fossil Sloth)

Five-million-year old sloth fossil found in Peru

click here for video

LIMA (Reuters) – The nearly intact fossil of an ancient sloth that lived 5 million years ago has been unearthed in Peru, a find about 4 million years older than similar ones discovered in the Americas, researchers said.

The sloth was found beneath the cement floor of a house in the Andean region of Espinar in southern Peru when workers were installing a water system. Parts of a giant armadillo that has also been dated to 5 million years ago were also found nearby.

The sloth, about 10 feet long, was an herbivore and lived during the Mio-Pliocene era, said paleontologist Rodolfo Salas of Peru’s Natural History Museum and one of the scientists on the dig sponsored by the French government.

“This skeleton of the sloth is especially important as it is the first complete skeleton of its kind that is 5 million years old in the Americas,” he told Reuters. “Previously, discoveries have been made of partial skeletons of similar animals, but from the Pleistocene era, meaning from the last million years.”

The sloth was found at 13,000 feet above sea level.

Salas said the sloth was relatively small compared with other animals of its type and would help researchers better understand evolution of mammals in the Andes.

Peru’s dry climate has helped preserve thousands of fossils from the Pacific coast to the Andes highlands, making it a favorite of fossil hunters.

(Reporting by Carlos Valdez; Writing by Terry Wade; Editing by Peter Cooney)

source: http://www.reuters.com/article/scienceNews/idUSTRE54P0H520090526

maggio 27, 2009 Posted by | - Mammiferi, America Southern, An. Vertebrates, Cenozoic, Multimedia, P - Geositi, P - Paleoantropologia, P - Ritrovamenti fossili, Paleontology / Paleontologia, Video | , , , , | Lascia un commento

2009-05-10 – Utah, USA: ritrovata una tartaruga fossile incinta (fossil pregnant turtle)

Rare prehistoric pregnant turtle found in Utah

At least three eggs are visible from the outside of the fossil, and Montana State University researchers this week have been studying images taken from a CT scan in search of others inside.

Montana State graduate student Michael Knell says the turtle was probably about a week from laying her eggs when she died and became entombed for millions of years in sandstone.

The fossil was found in 2006 in a remote part of Grand Staircase-Escalante National Monument. The eggs weren’t discovered until after it sat in storage for two years and was being re-examined by a volunteer.

This image provided Montana State University shows CT technician, Tanya Spence preparing to run a 75 million-year-old turtle fossil through a CT scanner at Deaconess Hospital in Bozeman, Mont. (AP Photo/Montana State University, Kelly Gorham)

This image provided Montana State University shows CT technician, Tanya Spence preparing to run a 75 million-year-old turtle fossil through a CT scanner at Deaconess Hospital in Bozeman, Mont. (AP Photo/Montana State University, Kelly Gorham)

maggio 10, 2009 Posted by | - Rettili, 1 Cretaceo, America Northern, An. Vertebrates, Articolo sc. di riferimento, Mesozoic, P - Preservazione eccezionale, P - Ritrovamenti fossili, Paleontology / Paleontologia, X - Nature | , , , , , , , , , | Lascia un commento

2009-03-14 – Vail, CAN: Gigant Palm tree fossil for sale

Colossal fossil comes to Vail

Palm tree frond from Eocene age takes up residence outside Lionshead Jewelers in Vail this weekend

Sarah Mausolf
smausolf@vaildaily.com
Vail CO, Colorado

Discovered in Wyoming, this palm tree frond fossil measures 14 by 8 feet, and includes 11 fish fossils. It will be on display this weekend outside Lionshead Jewelers in Vail.

Discovered in Wyoming, this palm tree frond fossil measures 14 by 8 feet, and includes 11 fish fossils. It will be on display this weekend outside Lionshead Jewelers in Vail.

 VAIL, Colorado — It weighs more than the world’s heaviest Sumo wrestler and is 800,000 times older than Dick Cheney.
Today through Sunday a 14-foot tall fossil will be on display outside Lionshead Jewelers in Vail.
Weighing in at 1,200 pounds and dating back 55 million years, the palm frond fossil is on sale for $200,000.
The Wyoming couple who found the fossil will be on hand to answer questions about their sizable discovery.
Bob and Bonnie Finney from just outside Kemmerer, Wyo., said they found the palm tree leaf in an area of Wyoming known as the Green River Formation. Once a 1,200-square-mile lake surrounded by tropical forest, this swath of land dried up as the Rocky Mountains formed, Bob Finney said. Today the land is a cattle ranch speckled with sagebrush — and a hotbed of fossils.
Bonnie Finney discovered the giant palm leaf in 2003 during a routine dig in her fossil quarry.
“I just said ‘Oh my God. I think it’s probably one of the biggest palm fronds ever found in the split fish,’” she said.
The split fish is a layer of rock in the Green River Formation where diggers split rocks open to find fossils.
Kirk Johnson, chief curator for the Denver Museum of Nature and Science in Denver, said the Green River Formation is unique because it is a source of intact palm frond fossils, as opposed to just frond fragments, which are common throughout the American West.
“What’s unusual about that particular site is they get whole ones there,” he said.
Most palm frond fossils are about six to seven feet long — roughly half the size of the frond at Lionshead Jewelers, he said. Still, Johnson doesn’t think the massive frond is breaking any size records.
“It’s not rare but it is spectacular,” Johnson said.
Perhaps more significant than the palm frond’s size is the message it sends about global warming, he said.
“These palms are really clear evidence that Wyoming was much warmer in the past than it is today. It’s sort of like a telegram from a warmer world, showing you what’s possible under different climate conditions on planet Earth,” he said.

Lionshead Jewelers has been selling fossils in a back room of the store for about seven years.
This weekend marks the first time the store will play host to the fossil hunters themselves.
“When you talk to the fossil diggers, it becomes more personal,” gallery owner Amad Akkad said. “You can see the excitement in their face because this is real.”

 

 What: Giant fossil
When: 10 a.m. to 8 p.m. today, Saturday and Sunday
Where: Lionshead Jewlers, 555 E. Lionshead Circle, Vail
Cost: Palm frond fossil is $200,000; Hundreds of smaller fossils from the Finneys will range from $50 to $200,000.
More information: 970-476-0499

 SOURCE: vaildaily.com

 

marzo 14, 2009 Posted by | Aste, Collezionismo, Paleontology / Paleontologia | , , , , | Lascia un commento

2009-02-14 – Aurorachelys, tartaruga fossile dalla Groenlandia (Greenlad, turtle fossil)

February 13, 2009

Ancient turtle fossil found on Axel Heiberg Island

Shell dates from warm period 90 million years ago

NUNATSIAQ NEWS

Geologists from the University of Rochester have uncovered a 90 million-year-old fossil of a tropical freshwater Asian turtle in Nunavut’s High Arctic.

The fossil was found in a slab of ancient basalt on Axel Heiberg Island.

The turtle, dubbed Aurorachelys, or aurora turtle, lived in the region 90 million years ago when polar temperatures averaged above 14 C, similar to those found in today’s northern Florida.


2009-02-14-aurorachelys
Turtles swam in Nunavut’s High Arctic 90 million years ago, say geologists who announced the find of this fossil turtle shell this week.
(PHOTO COURTESY OF THE UNIVERSITY OF ROCHESTER)

A paper on the fossil, published in the Feb. 1 journal Geology, suggests that carbon dioxide pouring into the atmosphere from volcanic activity during that period may have caused a “super-greenhouse” effect, boosting temperatures in the polar region.

“We’re talking about extremely warm, ice-free conditions in the Arctic region, allowing migrations across the pole,” said John Tarduno, professor of geophysics at the University of Rochester and leader of the team that found the turtle fossil, in a news release on the find.

The turtle resembles a kind of freshwater turtle found in Mongolia, so its presence in the High Arctic suggests that it may have migrated from Asia to North America by floating on a freshwater layer on top of the then-warm, salty Arctic Ocean.

Tarduno’s team found the fossil in 2006 when they went to the Arctic to study paleo-magnetism- that is, the Earth’s magnetic field in the far distant past.

Tarduno said study of the magnetism in rocks where the fossil was found rules out the possibility that the fossil came from southern waters. The turtle was clearly a native of the area, Tarduno noted.

At the time the aurora turtle lived, the Arctic Ocean was probably even more separated from the global oceanic circulation system than it is today, Tarduno said, and rivers would have poured fresh water into the ancient sea.

Fresh water is lighter than sea water, so Tarduno thinks fresh water may have rested on top of the salty water, allowing a freshwater animal such as the aurora turtle to migrate.

According to the news release, Tarduno also believes volcanoes could have produced a series of islands along an underwater mountain range in the Arctic Ocean called the Alpha Ridge.

If the ridge poked out above the surface of the water at one time, it would have given the turtles and other species the ability to island-hop all the way from ancient Russia to Canada, Tarduno said.

In recent years, Tarduno has uncovered fossils of other warm-water species in the High Arctic, such as crocodile-like beasts, which once thrived there 90 million years ago.

source: http://www.nunatsiaq.com/news/climate/90213_1907.html

febbraio 14, 2009 Posted by | - Rettili, 1 Cretaceo, An. Vertebrates, Mesozoic, P - Ritrovamenti fossili, Paleontology / Paleontologia | , , , , , , | Lascia un commento

2009-02-11 – Forlì, ITA: “Mostra di Minerali e Fossili”

Mostra minerali e fossili

Nei locali della Circoscrizione n. 3 al Foro Boario si svolgerà la “Mostra di Minerali e Fossili”. L’esposizione è gratuita e si svolgerà da giovedì 12 a domenica 15 febbraio dalle ore 9 alle 12,30 e dalle ore 15 alle 18.30. Per le scolaresche sono previste visite guidate previa prenotazione dal lunedì al venerdì dalle ore 8.30 alle ore 12, tel. 0543.712256 – 712109. Ai bambini intervenuti sarà dato in omaggio un minerale e un fossile. L’iniziativa è organizzata dal Gruppo Mineralogico e Paleontologico forlivese in collaborazione con la Circoscrizione 3 e l’Assessorato alle Politiche educative del Comune.

febbraio 11, 2009 Posted by | - Italia, Europa, Geology - Geologia, Lang. - Italiano, Mostre & Fiere, Paleontology / Paleontologia, Places | , , , , , , , , , , | Lascia un commento

2009-02-09 – Tac per Lucy (Australopithecus afarensis) (Hominid scanned)

Completata la scansione tridimensionale di Lucy, i risultati saranno utilizzati per provare a risolvere alcuni quesiti riguardanti la morfologia funzionale (postura, movimenti, possibilità di salire sugli alberi ….)

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Famous fossil Lucy scanned at the University of Texas at Austin

Data offers new insights into ancient human ancestor

AUSTIN, Texas—Researchers at The University of Texas at Austin, in collaboration with the Ethiopian government, have completed the first high-resolution CT scan of the world’s most famous fossil, Lucy, an ancient human ancestor who lived 3.2 million years ago.

Lucy is in the United States as part of a world premiere exhibit organized by the Houston Museum of Natural Science.

John Kappelman, professor of anthropology in the College of Liberal Arts, led the scientific team that conducted the scan of Lucy, whose remains include about 40 percent of her skeleton, making her the oldest and most complete skeleton of any adult, erect-walking human fossil.

“By examining the internal architecture of Lucy’s bones, we can study how her skeleton supported her movement and posture, and compare that to modern humans and apes,” Kappelman said. “Because Lucy is so complete, she is one of the few fossils that permit us to compare how she used her arms versus how she used her legs. These new data will allow us to examine the theory that she climbed about in the trees, as well as walked on two legs when she was on the ground.”

Although Lucy is small (about one meter tall), her contribution to science has been large. She represents a distinct species of human ancestor, known as Australopithecus afarensis, or “southern ape of Afar,” in reference to where the bones were found.

Prior to the 1974 discovery of Lucy, some theories of evolution suggested human-like intelligence evolved before upright posture (bipedalism). But the existence of ancient bipeds like Lucy refutes this theory because their brain is not significantly larger than that of a modern chimpanzee.

The Ethiopian government entrusted Lucy to Kappelman and Richard Ketcham, associate professor of geological sciences in the Jackson School of Geosciences and director of the university’s High-Resolution X-ray Computed Tomography Facility, one of the world’s premier labs for this work.

Scientists at the facility have scanned thousands of delicate fossils and biological specimens, including irreplaceable items such as the brain case of Archaeopteryx (one of the oldest and most primitive birds known). Because CT allows scientists to see inside fossils without doing any harm, it has become one of the most powerful tools for studying precious, one-of-a-kind specimens.

“We have more experience scanning natural history objects and dealing with the issues that can arise in scanning natural material than any other lab in the world,” Ketcham said. “The equipment is constantly updated and we’ve created a large, specialized toolkit to process the scan data and to extract the maximum amount of information from it. There’s no other place the Ethiopian government could have sent Lucy to get better imagery or to acquire it more safely.”

For 10 days the university team worked around the clock to scan all 80 pieces of Lucy’s skeleton. The scientists created custom-built foam mounts to safely hold the specimens in the scanner. And each piece was carefully examined before and after scanning to ensure that no damage occurred during the project.

The successful completion of Lucy’s scan means that the specimen is now safely archived in digital format, another of the reasons behind the scanning.

“These scans will ensure that future generations are familiar with Lucy,” said Jara Mariam, director general of Ethiopia’s Authority for Research and Conservation of Cultural Heritage, “and will know of Ethiopia’s central contribution to the study of human evolution. A virtual Lucy will be able to visit every classroom on the planet.”

“In some ways, scanning Lucy was the easy part,” Ketcham said. For the next several months, the research team, consisting of scientists from all around the country, will be reviewing and processing the data and generating images to analyze Lucy’s skeleton and begin to answer important questions ranging from whether she climbed among the tree branches to how she chewed.

This ancient hominin, whom Ethiopians call “Dinkenesh” (“You are beautiful”), is the feature attraction in the exhibit, “Lucy’s Legacy: The Hidden Treasures of Ethiopia,” which is touring the United States. More than a quarter million people viewed the fossil at Houston Museum of Natural Science during 2007 and 2008. After the brief layover in Austin for the scan, Lucy moved to the Pacific Science Center in Seattle where she is on exhibit through March.

Kappelman said the university’s scanning project represents a model for future collaborations between public educational programs and scientific research.

“There is an understandable tension between museum curators, who like to display fossils, and scientists who want to conduct research on the specimens,” Kappelman said. “Our project demonstrates these goals are not mutually exclusive—but mutually beneficial. The museum exhibit that features Lucy offers a once in a lifetime opportunity to introduce millions of people to the actual evidence for human evolution, and seeing the real fossil is so much more meaningful than viewing a plastic replica.”

“Having Lucy here also means that scientists can conduct research that asks new questions about the fossil and this knowledge feeds back into the ongoing exhibit and continues to educate,” Kappelman said. “Lucy may be old, but she still has lots of new secrets to tell.”

 ###

 In addition to Kappelman and Ketcham, the scientific team includes: Robert Fajardo at Harvard Medical School; Brian G. Richmond at George Washington University; Christopher Ruff at Johns Hopkins University School of Medicine; and Robert S. Scott at Rutgers, The State University of New Jersey.

Contacts: Christian Clarke Casarez, director of international public affairs, 512-232-6241 or christianc@austin.utexas.edu

J.B. Bird, communications coordinator, Jackson School of Geosciences, 512-232-9623, jbird@jsg.utexas.edu

Contact: Christian Clarke Casarez – christianc@austin.utexas.edu – 512-232-6241
University of Texas at Austin

source: http://www.eurekalert.org/pub_releases/2009-02/uota-ffl020209.php

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Ethiopian Review

Lucy 2.0: Famous Fossil Hominid Goes Digital
Wired News - 5 feb 2009
By Wired Science February 06, 2009 | 3:15:00 AMCategories: Anthropology, Evolution Lucy, the world’s most famous fossil human ancestor, has gone digital in 3-D. A new high-resolution CT scan of the 3.2 million-year-old skeleton will provide scientists
Famous fossil Lucy scanned at the University of Texas at Austin EurekAlert (press release)
Digital scans of “Lucy” take pre-humans inside out Reuters
San Antonio Express – Austin American-Statesman
e altri 39 articoli simili »

febbraio 9, 2009 Posted by | Italiano (riassunto), P - Paleoantropologia, Paleontology / Paleontologia | , , , , , , | Lascia un commento

2009-02-07 – Tra i fossili più antichi: Spugne (precambrian fossil sponges)

Antichissime impronte rinvenute nel precambriano dell’arabia Saudita sono state riconosciute come impronte di spugne. La scoperta ha ovviamente importantissime implicazioni di carattere ia tassonomico che soprattutto paleobiologico ed evoluzionistico

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Ancient sponges leave their mark

By Jonathan Amos
Science reporter, BBC News

Rocks in Oman
The rocks date to a time of dramatic gaciation on Earth

Traces of animal life have been found in rocks dating back 635 million years.

The evidence takes the form of chemical markers that are highly distinctive of sponges when they die and their bodies break down in rock-forming sediments.

The discovery in Oman pushes back the earliest accepted date for animal life on Earth by tens of millions of years.

Scientists tell Nature magazine that the creatures’ existence will help them understand better what the planet looked like all that time ago.

“The fact that we can detect these signals shows that sponges were ecologically important on the seafloor at that time,” said lead author Gordon Love, from the University of California, Riverside.

“We’re not saying we captured the first animal; we’re saying they’re an early animal phylum and we’re capturing them when their biomass was significant.”

Tiny creatures

Researchers can usually determine the presence of ancient life in rock strata by looking for the fossilised remains of skeletons or the hardened record of the creatures’ movements, such as their footprints or crawl marks.

Sponges
Sponges are among the simplest multi-celled organisms

But for organisms deep in geological history that were extremely small and soft bodied, scientists have had to develop novel techniques to uncover their existence.

One of these newer methods involves detecting breakdown products from the lipid molecules which act as important structural components in the cell membranes of animals.

Over time, these will transform to leave a molecule known as cholestrane; and for sponges, this exclusively takes the form known as 24-isopropylcholestane.

Dr Love’s team found high concentrations of this biomarker in rocks located at the south-eastern edge of the Arabian peninsula.

They were laid down in what would have been a shallow marine environment at least 635 million years ago.

“Even though there must have been sufficient oxygen in the water to maintain the metabolism of these primitive animals, I think their size would have been restricted by oxygen being nowhere near modern values,” the UC Riverside researcher said.

“We’re probably talking about small colonies of sponges with body dimensions of a few millimetres at most. They’d have been filtering organic detritus in the water column.”

Icy planet

The discovery is fascinating because it pre-dates the end of the Marinoan glaciation, a deep freeze in Earth history that some argue shrouded the entire planet in ice.

Scientists often refer to the term “snowball Earth” to describe conditions at this time.

So to find animal life apparently thriving during this glaciation seems remarkable, commented Jochen Brochs, from the Australian National University, Canberra.

“If there really was a snowball Earth, how did those sponges survive? The full snowball Earth hypothesis would predict that the oceans were frozen over by 2km, even at the equator,” he told BBC News.

“Only at hot springs could any organism survive but it is questionable that you would have sponges in a hot spring. I haven’t made my mind up about snowball Earth but perhaps these sponges are telling us something about this glaciation.”

Dr Love’s view is that the presence of these animals puts limits on the scale of the ice coverage.

“I believe there were areas of what we might call refugia – areas of open ocean where biology could go on. And in this case, it could be evidence that we had some sort of evolutionary stimulation of new grades of organisms as well.”

Jonathan.Amos-INTERNET@bbc.co.uk

 

http://news.bbc.co.uk/2/hi/science/nature/7871099.stm

febbraio 7, 2009 Posted by | An. Invertebrates, Articolo sc. di riferimento, Asia, Bl - Top posts, Italiano (riassunto), P - Preservazione eccezionale, P - Ritrovamenti fossili, Paleontology / Paleontologia, Precambriano, X - Nature | , , , , , , , | Lascia un commento

2009-02-06 – Titanoboa, il serpente più grande di sempre (the greatest fossil snake)

click here for video.

E’ Titanoboa il serpente più grosso del mondo

Viveva 60 milioni di anni fa in Colombia e aveva misure record: 13 metri di lunghezza per oltre una tonnellata di peso. Ossa fossili scoperte da una spedizione internazionale in Colombia
di ALESSIA MANFREDI 

OLTRE una tonnellata di peso distribuita su 13 metri di lunghezza. Misure decisamente oversize, paragonabili ad un Tyrannosaurus Rex, quelle del serpente più lungo del mondo, che, secondo un’équipe internazionale di scienziati, viveva 60 milioni di anni fa in Sud America.

La stazza del biscione giurassico è stata dedotta sulla base di ossa fossili ritrovate dai ricercatori dello Smithsonian Tropical Research Institute a Panama e del Museo di Storia Naturale dell’Università della Florida nel Cerrejon, nella Colombia del Nord.

Battezzato dai suoi scopritori Titanoboa Cerrejonensis, questo rettile gigante misurava 13 metri, pesava 1.140 chili e il suo corpo era largo almeno un metro, scrivono su Nature gli scienziati guidati dal paleontologo Jason Head dell’Università di Toronto-Mississauga. Messa a confronto con quella di una normale anaconda, la sua vertebra risulta enorme.

GUARDA LE FOTO

Il Titanoboa viveva fra 58 e 60 milioni di anni fa, quando il mondo animale si stava ancora riprendendo dall’estinzione di massa che fece scomparire i dinosauri e molte altre specie 65 milioni di anni fa, e potrebbe essere stato il più grande vertebrato non marino sulla Terra.

Le sue impressionanti dimensioni danno anche indicazioni precise sulle temperature dell’ambiente in cui viveva. “Ci sono molti modi in cui l’anatomia di una specie è correlata con l’ambiente su larga scala”, ha spiegato David Polly, geologo dell’Università dell’Indiana, che ha identificato la posizione delle vertebre fossili ritrovate nella miniera di carbone a cielo aperto del Cerrejon ed ha reso possibile ricostruire le misure del rettile. Per sopravvivere, stimano i ricercatori, il mega serpente aveva bisogno di una temperatura media di almeno 30-34 gradi, superiore a quella odierna in quella regione.


Il Titanoboa abitava in una foresta pluviale tropicale e cacciava coccodrilli, tartarughe e pesci. Non era velenoso ed aveva uno stile di vita molto simile a quello delle anaconde dei sistemi fluviali. L’ecosistema in cui viveva era simile a quello dell’Amazzonia di oggi, ma più caldo. “Gli ecosistemi tropicali del Sud America erano sorprendentemente diversi 60 milioni di anni fa”, dice il paleontologo Jonathan Bloch, del Museo di Storia Naturale dell’Università della Florida. “Era una foresta pluviale ma decisamente più calda rispetto a oggi ed i rettili a sangue freddo erano molto molto più grossi rispetto quelli odierni”.

Nella spedizione al Cerrejon, gli scienziati hanno recuperato fossili di vertebre e costole provenienti da 28 esemplari diversi. Prima della scoperta del Titanoboa, il serpente più grosso noto alla scienza era Gigantophis, che viveva 39 milioni di anni fa in Egitto ed era lungo 10 metri.

(4 febbraio 2009)

http://www.repubblica.it/2009/02/sezioni/scienze/serpente-colombia/serpente-colombia/serpente-colombia.html

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Ancient snake’s massive size points to extra hot jungle: study

Last Updated: Wednesday, February 4, 2009 | 1:53 PM ET

Researchers have found the remains of what they are billing as the biggest snake the world has ever known — an animal estimated to be longer than a city bus and heftier than a car.

The boa constrictor-like reptile lived in South America about 60 million years ago and its size provides valuable clues about what the climate was like in the equatorial tropics at that time, said a study published in Thursday’s issue of the journal Nature by an international team of authors that included University of Toronto paleontologist Jason Head.

“If it was around today and it swallowed you, you wouldn’t even be a bulge in its belly,” said Head.

He said he first saw one of the snake’s giant vertebrae, the bones in its backbone, while chatting online with co-author Jonathan Bloch, from the University of Florida, who held them up in front of webcam.

“I jumped out of my seat and got very excited and he started laughing and I started laughing … because it’s just such a mind-bogglingly big animal,” Head recalled.

Based on the size of the snake’s vertebrae — the largest ever for either a living or extinct snake — the researchers estimate that the ancient snake could have grown to be 13 metres long and weigh about 1,135 kilograms.

Head said the largest modern snakes are reticulated pythons, which reach a length of about nine metres, and green anacondas, which can grow to be 7.5 metres long.

Researchers found the vertebrae and ribs for about 28 individual snakes of this species, which was given the name Titanoboa cerrejonensis to indicate its great size and the fact that it was found in the Cerrejon region of northeastern Colombia. The type of pollen found with it suggested that it lived about 58 to 60 million years ago, roughly six to eight million years after the dinosaurs went extinct.

Head said cold-blooded animals such as snakes can’t generate their own heat, so they need an external heat source to power their metabolisms. Because larger animals have slower metabolisms, larger cold-blooded animals need more heat.

Hotter climate lets cold-blooded animals grow

Scientists have already studied the size of snakes living at different temperatures, and found that their maximum size is proportional to the average temperature. Based on what they know about that relationship, as well as the size and environment of the living anaconda, which is similar, the study estimated that the largest specimens of Titanboa would have needed an environment where the average temperature was at least 33 C — about six degrees warmer than equatorial South America is today — in order to survive.

The Titanboa fossils were found in an open pit coal mine, alongside fossilized giant turtles, as well as fossils of primitive crocodiles that the snake likely ate. The snake likely spent most of its time in the water, as anacondas do, Head said.

Fossils from the tropics are difficult to find, Head said, because so much of the area is covered by jungle rather than bare rock or sand. That means there is little data about what the ancient climate was like there.

“Fortunately, the owners of the Cerrejon mine had the presence of mind to be interested in the fossils they were finding,” he said.

The mine owners worked with Carlos Jaramillo of the Smithsonian Tropical Research Institute in Panama and Bloch, who eventually consulted Head because his research specialty is fossil snakes.

http://www.cbc.ca/technology/story/2009/02/04/tech-giant-snake.html

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Times Online

Discovery of 43-Foot Snake Fossil Signals Warmer Tropical Past
Bloomberg - 4 ore fa
The discovery of fossil vertebrae in a coal mine in Cerrejon, Colombia, signifies the largest known snake, one that couldn’t have survived unless temperatures averaged 30 to 34 degrees Celsius, (86 to 93 degrees Fahrenheit), scientists wrote in the
Fossil remains of world’s biggest snake are found International Herald Tribune
Fossil of giant 13-metre snake found in Colombia Irish Times
Los Angeles Times – USA Today – The Associated Press – guardian.co.uk
e altri 335 articoli simili »

http://news.ufl.edu/2009/02/04/largest-snake-fossil/

 

febbraio 6, 2009 Posted by | - Rettili, America Southern, An. Vertebrates, Cenozoic, G - Geographic Distribution, P - Ritrovamenti fossili, Paleontology / Paleontologia | , , , , , , , | Lascia un commento

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