July 3, 2008, 9:18 PM CT

Species Have Come and Gone

View a video interview with researcher John Alroy of the National Center for Ecological Analysis and Synthesis.

Diversity among the ancestors of such marine creatures as clams, sand dollars and lobsters showed only a modest rise beginning 144 million years ago with no clear trend afterwards, according to an international team of researchers. This contradicts previous work showing dramatic increases beginning 248 million years ago and may shed light on future diversity.

"Some of the time periods in the past are analogies for what is happening today from global warming," says Jocelyn Sessa of Penn State. "Understanding what happened with diversity in the past can help us provide some prediction on how modern organisms will fare. If we know where we have been, we know something about where it will go".

Using contemporary statistical methods and a paleobiology database, the researchers report in the July 4 issue of Science, a new diversity curve that shows that most of the early spread of invertebrates took place well before the Late Cretaceous, and that the net increase through the period since, is proportionately small relative to the 65 million years that elapsed. The research team was led by John Alroy of the University of California at Santa Barbara......... Posted by: William      Read more         Source

June 17, 2008, 9:40 PM CT

The Mystery of Mass Extinctions Is No Longer Murky

If you are curious about Earth's periodic mass extinction events such as the sudden demise of the dinosaurs 65 million years ago, you might consider crashing asteroids and sky-darkening super volcanoes as culprits.

But a new study, published June 15, 2008, in the journal Nature, suggests that it is the ocean, and in particular the epic ebbs and flows of sea level and sediment over the course of geologic time, that is the primary cause of the world's periodic mass extinctions over the past 500 million years.

"The expansions and contractions of those environments have pretty profound effects on life on Earth," says Shanan Peters, a University of Wisconsin-Madison assistant professor of geology and geophysics and the author of the new Nature report. In short, as per Peters, changes in ocean environments correlation to sea level exert a driving influence on rates of extinction, which animals and plants survive or vanish, and generally determine the composition of life in the oceans.

Since the advent of life on Earth 3.5 billion years ago, researchers think there may have been as a number of as 23 mass extinction events, a number of involving simple forms of life such as single-celled microorganisms. Over the past 540 million years, there have been five well-documented mass extinctions, primarily of marine plants and animals, with as a number of as 75-95 percent of species lost. For the most part, researchers have been unable to pin down the causes of such dramatic events. In the case of the demise of the dinosaurs, researchers have a smoking gun, an impact crater that suggests dinosaurs were wiped out as the result of a large asteroid crashing into the planet. But the causes of other mass extinction events have been murky, at best......... Posted by: William      Read more         Source

June 10, 2008, 8:23 PM CT

Cutting-edge weapons result of prehistoric experimentation

In today's fast-paced, technologically advanced world, people often take the innovation of new technology for granted without giving much thought to the trial-and-error experimentation that makes technology useful in everyday life. When the "cutting-edge" technology of the bow and arrow was introduced to the world, it changed the way humans hunted and fought. University of Missouri archaeologists have discovered that early man, on the way to perfecting the performance of this new weapon, engaged in experimental research, producing a great variety of projectile points in the quest for the best, most effective system.

"Technological innovation and change has become a topic that interests people," said R. Lee Lyman, professor and chair of the University of Missouri Department of Anthropology. "When the bow and arrow appeared in North America, roughly 1,500 years ago, it eventually replaced the atlatl (spear thrower) and dart. The introduction of the bow and arrow, a different weapon delivery system, demanded some innovative thinking and technology. In other words, one could not just shoot a dart from a bow. Components like the shaft and arrow point needed to be reinvented".

Because the necessary flight dynamics and mechanics of the arrow wouldn't have been fully understood, the indigenous people at the time would have experimentedtrying all sorts of points with different types of shafts, attempting to discover the best combinations. This reinvention process can be seen archaeologically through an increase in the number and variation of projectile pointsindicating the transition period between the atlatl and the bow and arrow......... Posted by: William      Read more         Source

June 10, 2008, 8:15 PM CT

Lost Reds In Homer Painting

More than 30 years ago, when Northwestern University chemist Richard Van Duyne developed a powerful new sensing technique, he never thought he would be using it to learn more about treasures in the Art Institute of Chicago's collection -- including a watercolor recently featured in the museum's exhibition "Watercolors by Winslow Homer: The Color of Light".

In Homer's watercolor "For to be a Farmer's Boy," painted in 1887, some of the red and yellow pigments have faded in the sky, leaving that area virtually without color. Van Duyne, Charles E. and Emma H. Morrison Professor of Chemistry in the Weinberg College of Arts and Sciences, is working with Francesca Casadio, a conservation scientist at the Art Institute, to determine what the original colors were.

To solve this mystery, they are using surface enhanced Raman spectroscopy (SERS), the analytical technique pioneered by Van Duyne in 1977. SERS uses laser light and nanoparticles of precious metals to interact with molecules to show the chemical make-up of a particular dye.

SERS is a variation of Raman spectroscopy, a widely used technique first developed in the 1920s. What sets SERS apart is its ability to analyze extremely minute samples of organic dyes; some samples are so small they cannot be seen by the naked eye......... Posted by: Sarah      Read more         Source

June 9, 2008, 8:02 PM CT

New research refutes myth of pure Scandinavian race

team of forensic researchers at the University of Copenhagen has studied human remains found in two ancient Danish burial grounds dating back to the iron age, and discovered a man who appears to be of arabian origin. The findings suggest that human beings were as genetically diverse 2000 years ago as they are today and indicate greater mobility among iron age populations than was previously thought. The findings also suggest that people in the Danish iron age did not live and die in small, isolated villages but, on the contrary, were in constant contact with the wider world.

On the southern part of the island of Zealand in Denmark, lie two burial grounds known as Bøgebjerggård and Skovgaarde, which date back to the Danish iron age (c. 0-400 BC). Linea Melchior and forensic researchers from the University of Copenhagen analysed the mitocondrial DNA of 18 individuals buried on the sites and observed that there was as much genetic variation in their remains as one would expect to find in individuals of the present day. The research team also found DNA from a man, whose genetic characteristics indicate a man of Arabian origin.

The ancestors of the Danes were in contact with the wider world.

Archeologists and anthropologists know today that the concept of a single scandinavian genetic type, a scandinavian race that wandered to Denmark, settled there, and otherwise lived in complete isolation from the rest of the world, is a fallacy......... Posted by: William      Read more         Source

May 12, 2008, 8:05 PM CT

Ancient Beachcombers May Have Travelled Slowly

New evidence, more questions. That's the thumbnail of the first new data reported in 10 years from Monte Verde, the earliest known human settlement in the Americas.

Evidence from the archaeological site in southern Chile confirms Monte Verde is the Americas earliest known settlement and is consistent with the idea that early human migration occurred along the Pacific Coast more than 14,000 years ago, but questions remain about just how rapidly that migration occurred.

"If all the early American groups were following a similar pattern of moving back and forth between inland and coastal areas, then the peopling of the Americas may not have been the blitzkrieg movement to the south that people have presumed, but a much slower and more deliberate process," says Tom Dillehay, professor of anthropology at Vanderbilt University, Nashville, Tenn., who led the study.

The journal Science publishes a report on the findings by Dillehay and team of international researchers in its May 9 issue.

"Monte Verde is an iconic site in New World archaeology and Americanist archaeologists recognize its importance," says John Yellen, program manager at the National Science Foundation, which funded the research. "They also agree that Tom Dillehay has conducted an outstanding program of research there"......... Posted by: William      Read more         Source

April 30, 2008, 6:26 PM CT

Ancient "Nutcracker Man" Challenges Ideas on Evolution

Tiny marks on the teeth of an ancient human ancestor known as the "Nutcracker Man" may upset current evolutionary understanding of early hominid diet.

Using high-powered microscopes, scientists looked at rough geometric shapes on the teeth of several Nutcracker Man specimens and determined that their structure alone was not enough to predict diet.

Peter Ungar, professor of anthropology at the University of Arkansas in Fayetteville, contends the finding shows evolutionary adaptation for eating may have been based on scarcity rather than on an animal's regular diet.

"These findings totally run counter to what people have been saying for the last half a century," says Ungar. "We have to sit back and re-evaluate what we once thought.".

Ungar and colleagues, Frederick E. Grine of State University of New York at Stony Brook and Mark F. Teaford of Johns Hopkins University, Baltimore, Md., reported their findings last week in the Public Library of Science One, a peer-evaluated, international, online journal. The research was funded in part by the National Science Foundation.

The scientists examined the teeth of Paranthropus boisei, an ancient hominin that lived between 2.3 and 1.2 million years ago and is known popularly as the "Nutcracker Man" because it has the biggest, flattest cheek teeth and the thickest enamel of any known human ancestor......... Posted by: William      Read more         Source

April 24, 2008, 9:33 PM CT

Genetic Sequencing of Protein from T. Rex

Researchers have put more meat on the theory that dinosaurs' closest living relatives are modern-day birds.

Molecular analysis, or genetic sequencing, of a 68-million-year-old Tyrannosaurus rex protein from the dinosaur's femur confirms that T. rex shares a common ancestry with chickens, ostriches, and to a lesser extent, alligators.

The dinosaur protein was wrested from a fossil T. rex femur discovered in 2003 by paleontologist John Horner of the Museum of the Rockies; the bone was found in a fossil-rich stretch of land in Wyoming and Montana.

The new research results, published this week in the journal Science, represent the first use of molecular data to place a non-avian dinosaur in a phylogenetic tree, a "tree of life," that traces the evolution of species.

"These results match predictions made from skeletal anatomy, providing the first molecular evidence for the evolutionary relationships of a non-avian dinosaur," says Science paper co-author Chris Organ, a researcher at Harvard University. "Even though we only had six peptides--just 89 amino acids--from T. rex, we were able to establish these relationships".

"Tests of the peptide sequences in T. rex bone fossils have confirmed that newer methods of molecular systematics agree with more traditional methods of taxonomic classification based on morphology, or shapes," says Paul Filmer, program director in the National Science Foundation (NSF)'s Division of Earth Sciences, which funded the research......... Posted by: William      Read more         Source

April 22, 2008, 8:54 PM CT

Rewrite Fossil History Of Shell-breaking Crab

While waiting for colleagues at a small natural history museum in the state of Chiapas, Mexico last year, Cornell paleontologist Greg Dietl chanced upon a discovery that has helped rewrite the evolutionary history of crabs and the shelled mollusks upon which they preyed.

In a museum display case he recognized a 67- to 69-million-year-old fossil from the Late Cretaceous period of a big crab with an oversized right claw. Such crabs with claws of different sizes were not known to exist until the early Cenozoic era, about 20 million years later. Aside from being larger than most known Late Cretaceous crabs (about the size of today's Florida stone crabs) and having asymmetrical claws, this ancient crab also sported a curved tooth on the movable finger of the larger right claw. This was another specialized adaptation that paleontologists thought developed millions of years later for peeling snail shells open.

"I immediately had to point it out to my colleagues around me," said Dietl, an adjunct professor in Cornell's Department of Earth and Atmospheric Sciences and director of collections at the Cornell-affiliated Paleontological Research Institution in Ithaca. "I was really excited when I found it. The fossil re-opens the question of the role crabs played in the well-documented restructuring of marine communities that occurred during the Mesozoic era [251 million years ago to 65 million years ago]."........ Posted by: William      Read more         Source

April 10, 2008, 9:05 PM CT

Grand Canyon may be as old as dinosaurs

New geological evidence indicates the Grand Canyon may be so old that dinosaurs once lumbered along its rim, as per a research studyby scientists from the University of Colorado at Boulder and the California Institute of Technology.

The team used a technique known as radiometric dating to show the Grand Canyon may have formed more than 55 million years ago, pushing back its assumed origins by 40 million to 50 million years. The scientists gathered evidence from rocks in the canyon and on surrounding plateaus that were deposited near sea level several hundred million years ago before the region uplifted and eroded to form the canyon.

A paper on the subject would be reported in the recent issue of the Geological Society of America Bulletin. CU-Boulder geological sciences Assistant Professor Rebecca Flowers, lead author and a former Caltech postdoctoral researcher, collaborated with Caltech geology Professor Brian Wernicke and Caltech geochemistry Professor Kenneth Farley on the study.

"As rocks moved to the surface in the Grand Canyon region, they cooled off," said Flowers. "The cooling history of the rocks allowed us to reconstruct the ancient topography, telling us the Grand Canyon has an older prehistory than a number of had thought".

The team believes an ancestral Grand Canyon developed in its eastern section about 55 million years ago, later linking with other segments that had evolved separately. "It's a complicated picture because different segments of the canyon appear to have evolved at different times and subsequently were integrated," Flowers said......... Posted by: William      Read more         Source

April 1, 2008, 9:55 PM CT

356 animal inclusions trapped in 100 million years old opaque amber

Paleontologists from the University of Rennes (France) and the ESRF have found the presence of 356 animal inclusions in completely opaque amber from mid-Cretaceous sites of Charentes (France). The team used the X-rays of the European light source to image two kilogrammes of the fossil tree resin with a technique that allows rapid survey of large amounts of opaque amber. At present this is the only way to discover inclusions in fully opaque amber.

Opaque amber has always been a challenge for paleontologists. Scientists cannot study it because the naked eye cannot visualize the presence of any fossil inclusion inside. In the Cretaceous sites like those in Charentes, there is up to 80% of opaque amber. It is like trying to find, in complete blindness, something that may or may not be there.

However, the paleontologists Malvina Lak, her colleagues from the University of Rennes and the ESRF paleontologist Paul Tafforeau, together with the National Museum of Natural History of Paris, have applied to opaque amber a synchrotron X-ray imaging technique known as propagation phase contrast microradiography. It sheds light on the interior of this dark amber, which resembles a stone to the human eye. "Scientists have tried to study this kind of amber for a number of years with little or no success. This is the first time that we can actually discover and study the fossils it contains", says Paul Tafforeau......... Posted by: William      Read more         Source

Sun, 30 Mar 2008 21:23:27 GMT

Come Blow Your Horn

I''ve been a little lax keeping up with paleontology these days, despite my daughter''s frequent reminder that I''ve yet to make the hadrosaur T-shirts she''s been asking for. Last month A Hadrosuarian dinosaur was found in the Coahuila desert of Mexico:

You can learn more about theVelafrons coahuilensis HERE and HERE.

Now this month they''ve uncovered another skull in that same area, this of a creature similar to triceratops. The expectation is that several other new species may be found.

I think a lot of us in who aren''t in the sciences tend to loose track of the rich diversity of life in previous ages. It''s fairly easy for us to see some degree of diversity today, but our imagination can hardly embrace the richness and variety of life on earth, often not even considering life in the oceans or microscopic life when we think about that variety. How much more difficult it is to imagine the past. We tend to think that dinosaurs came in a few dozen "flavors" and that everything is just a variation of that, yet the discovery of these new species and the characteristics they share with other animals of their age as well as the characteristics that distinguish them from similar animals only serves to remind us what a rich spectrum life has evolved in.

How beautiful and marvelous that nature has selected and molded each creature over time to fit in it''s changing niche, How awesome the diversity in how these animals moved, fought off predators, attracted mates, and found food! With each new fossil comes more understanding and more wonder.... and it only makes me sad for the creationists who believe in a young, little world with so little diversity and wonder. Posted by: Dorid      Read more     Source

March 20, 2008, 8:16 PM CT

Domestication of the donkey

An international group of researchers, led by Fiona Marshall, Ph.D., professor of anthropology in Arts & Sciences, has found evidence for the earliest transport use of the donkey and the early phases of donkey domestication, suggesting the process of domestication may have been slower and less linear than previously thought.

Based on a study of 10 donkey skeletons from three graves dedicated to donkeys in the funerary complex of one of the first Pharaohs at Abydos, Egypt, the team, led by Marshall and Stine Rossel of the University of Copenhagen, observed that donkeys around 5,000 years ago were in an early phase of domestication. They looked like wild animals but displayed joint wear that showed that they were used as domestic animals.

"Genetic research has suggested African origins for the donkey," said Marshall. "But coming up with an exact time and location for domestication is difficult because signs of early domestication can be hard to see. Our findings show that traces of human management can indicate domestication before skeletal or even genetic changes."

The previously unpublished research was presented in "Domestication of the Donkey: New Data on Timing, Process and Indicators" in the March 10 online edition of the Proceedings of the National Academy of Sciences......... Posted by: William      Read more         Source

March 3, 2008, 10:04 PM CT

Unknown aspects of China's past

CHICAGOImagine future archaeologists trying to understand Illinois, California or New York based on a few excavations in each of those states. They might excavate small areas in city centers, since those sites would probably be the first ruins they would come across. Meanwhile, the archaeologists they might fail to notice or study farms, suburbs, shopping malls, canals and airports.

Eventhough still relatively unknown to the general public, an archaeological method that is being practiced at several locations around the world helps researchers overcome such bias toward large, readily noticeable sites. The method is called a regional settlement pattern survey. It involves walking systematically over a large landscape to find traces of archaeological sites on the surface of the ground. This field procedure can yield a holistic, integrated view of how settlement has shifted in a region over the course of history.

For the past 13 years, archaeologists from The Field Museum and Shandong University have used this method to develop a multifarious overview of an important but understudied region along the northeastern coast of The Peoples Republic of China. By the time the project is completed, the archaeologists expect to have walked systematically over 1,500 square kilometers around the coastal city of Rizhao in Shandong Province......... Posted by: William      Read more         Source

March 3, 2008, 10:00 PM CT

40,000 year old tooth and Neanderthal movement

A 40,000-year-old tooth has provided researchers with the first direct evidence that Neanderthals moved from place to place during their lifetimes. In a collaborative project involving scientists from the Gera number of, the United Kingdom, and Greece, Professor Michael Richards of the Max Planck institute for Evolutionary Anthropology in Leipzig, Gera number of and Durham University, UK, and his team used laser technology to collect microscopic particles of enamel from the tooth. By analysing strontium isotope ratios in the enamel - strontium is a naturally occurring metal ingested into the body through food and water - the researchers were able to uncover geological information showing where the Neanderthal had been living when the tooth was formed (Journal of Archaeological Science, February 11th, 2008).

The tooth, a third molar, was formed when the Neanderthal was aged between seven and nine. It was recovered in a coastal limestone cave in Lakonis, in Southern Greece, during an excavation directed by Dr Eleni Panagopoulou of the Ephoreia of Paleoanthropology and Speleology (Greek Ministry of Culture). The strontium isotope readings, however, indicated that the enamel formed while the Neanderthal lived in a region made up of older volcanic bedrock. The findings, reported in the Journal of Archaeological Science, could help answer a long-standing debate about the mobility of the now extinct Neanderthal species......... Posted by: William      Read more         Source

February 26, 2008, 5:18 PM CT

Giant Fossil Frog from Hell

A team of researchers, led by Stony Brook University paleontologist David Krause, has discovered the remains in Madagascar of what may be the largest frog ever to exist.

The 16-inch, 10-pound ancient frog, scientifically named Beelzebufo, or devil frog, links a group of frogs that lived 65 to 70 million years ago with frogs living today in South America.

Discovery of the voracious predatory fossil frog -- reported on-line this week in the journal Proceedings of the National Academy of Sciences (PNAS) -- is significant in that it may provide direct evidence of a one-time land connection between Madagascar, the largest island off Africa's southeast coast, and South America.

To identify Beelzebufo and determine its relationship to other frogs, Krause collaborated with fossil frog experts Susan Evans, lead author of the PNAS article, and Marc Jones of the University College London. The authors concluded that the new frog represents the first known occurrence of a fossil group in Madagascar with living representatives in South America.

"Beelzebufo appears to be a very close relative of a group of South American frogs known as 'ceratophyrines,' or 'pac-man' frogs, because of their immense mouths," said Krause, whose research was funded by the National Science Foundation (NSF). The ceratophryines are known to camouflage themselves in their surroundings, then ambush predators......... Posted by: William      Read more         Source

February 25, 2008, 9:07 PM CT

Royals weren't only builders of Maya temples

An intrepid archaeologist is well on her way to dislodging the prevailing assumptions of scholars about the people who built and used Maya temples.

From the grueling work of analyzing the "attributes," the nitty-gritty physical details of six temples in Yalbac, a Maya center in the jungle of central Belize - and a popular target for antiquities looters - primary investigator Lisa Lucero is building her own theories about the politics of temple construction that began nearly two millennia ago.

Her findings from the fill, the mortar and other remnants of jungle-wrapped structures lead her to think that kings weren't the only people building or sponsoring Late Classic period temples (from about 550 to 850), the stepped pyramids that rose like beacons out of the southern lowlands as early as 300 B.C.

"Preliminary results from Yalbac suggest that royals and nonroyals built temples," said Lucero, a professor of anthropology at the University of Illinois.

In fact, judging by the varieties of construction and materials, any number of different groups - nobles, priests and even commoners - may have built temples, Lucero said, and their temples undoubtedly served their different purposes and gods.

That different groups had the wherewithal - the will, resources and freedom - to build temples suggests to Lucero that "the Maya could choose which temples to worship in and support; they had a voice in who succeeded politically"......... Posted by: William      Read more         Source

February 6, 2008, 8:14 PM CT

Crayfish Fossils Provide Missing Evolutionary Link

Crayfish body fossils and burrows discovered in Victoria, Australia, have provided the first physical evidence that crayfish existed on the continent as far back as the Mesozoic Era, says Emory University paleontologist Anthony Martin, who headed up a study on the finds.

"Studying the fossil burrows gives us a glimpse into the ecology of southern Australia about 115 million years ago, when the continent was still attached to Antarctica," says Martin, a senior lecturer in environmental studies at Emory and an honorary research associate at Monash University in Melbourne. During that era, diverse plants grew in what is today Antarctica and dinosaurs roamed in prolonged polar darkness along southern Australia river plains. The period is of particular interest to researchers since it is thought to bethe last time the Earth experienced pronounced global warming, with an average temperature of 68 degrees Fahrenheit - just 10 degrees warmer than today.

On Feb. 2, the earth science journal Gondwana Research published online the results of the crayfish study, which was conducted by Martin and a consortium of Australian scientists, including Thomas Rich and Gary Poore of the Museum of Victoria; Mark Schultz and Christopher Austin of Charles Darwin University; and Lesley Kool and Patricia Vickers-Rich of Monash......... Posted by: William      Read more         Source

February 4, 2008, 9:55 PM CT

Hidden art could be revealed by new terahertz device

Like X-rays let doctors see the bones beneath our skin, "T-rays" could let art historians see murals hidden beneath coats of plaster or paint in centuries-old buildings, University of Michigan engineering scientists say.

T-rays, pulses of terahertz radiation, could also illuminate penciled sketches under paintings on canvas without harming the artwork, the scientists say. Current methods of imaging underdrawings can't detect certain art materials such as graphite or sanguine, a red chalk that some of the masters are believed to have used.

The team of researchers, which includes researchers at the Louvre Museum, Picometrix, LLC and U-M, used terahertz imaging to detect colored paints and a graphite drawing of a butterfly through 4 mm of plaster. They believe their technique is capable of seeing even deeper. A paper on the research is reported in the February edition of Optics Communications.

In March, the researchers will take their equipment to France to help archaeologists examine a mural they discovered recently behind five layers of plaster in a 12th century church.

"It's ideal that the method of evaluation for historical artifacts such as frescoes and mural paintings, which are typically an inherent part of a building's infrastructure, be non-destructive, non-invasive, precise and applicable on site. Current technologies may satisfy one or more of these requirements, but we believe our new technique can satisfy all of them," said John Whitaker, an author of the paper who is a research scientist and adjunct professor in the Department of Electrical Engineering and Computer Science at U-M......... Posted by: William      Read more         Source

January 24, 2008, 11:03 PM CT

New Discoveries At The Ash Altar Of Zeus

The Greek traveler, Pausanias, living in the second century, CE, would probably recognize the spectacular site of the Sanctuary of Zeus at Mt. Lykaion, and especially the altar of Zeus. At 4,500 feet above sea level, atop the altar provides a breathtaking, panoramic vista of Arcadia.

"On the highest point of the mountain is a mound of earth, forming an altar of Zeus Lykaios, and from it most of the Peloponnesos can be seen," wrote Pausanias, in his famous, well-respected multi-volume Description of Greece. "Before the altar on the east stand two pillars, on which there were of old gilded eagles. On this altar they sacrifice in secret to Lykaion Zeus. I was reluctant to pry into the details of the sacrifice; let them be as they are and were from the beginning".

What would surprise Pausanias-as it is surprising archaeologists-is how early that "beginning" actually may be. New pottery evidence from excavations by the Greek-American, interdisciplinary team of the Mt. Lykaion Excavation and Survey Project indicates that the ash altar-a cone of earth located atop the southern peak of Mt Lykaion where dedications were made in antiquity- was in use as early as 5,000 years ago-at least 1,000 years before the early Greeks began to worship the god Zeus.

In addition, a rock crystal seal, bearing an image of a bull, of probable Late Minoan times (1500-1400 BCE) and also found on the altar, suggests an intriguing early correlation between the Minoan isle of Crete and Arcadia, and bears witness to another chapter in what now appears to be an particularly long history of activity atop the mountain......... Posted by: William      Read more         Source

January 14, 2008, 5:35 PM CT

T.-rex had teen pregnancies

Dinosaurs had pregnancies as early as age 8, far before they reached their maximum adult size, a new study finds.

Scientists at Ohio University and University of California at Berkeley have found medullary bone the same tissue that allows birds to develop eggshells in two new dinosaur specimens: the meat-eater Allosaurus and the plant-eater Tenontosaurus. Its also been found in Tyrannosaurus rex.

The discovery allowed scientists to pinpoint the age of these pregnant dinosaurs, which were 8, 10 and 18. That suggests that the creatures reached sexual maturity earlier than previously thought, as per the scientists, who will publish their study Jan. 15 in the journal Proceedings of the National Academy of Sciences.

The researchers originally studied the bones, which come from different geologic periods, to learn more about dinosaur growth rates. Because scientists rarely find fossils of adult dinosaurs, some have speculated that the ancient beasts never stopped developing, said Andrew Lee, a postdoctoral student at the Ohio University College of Osteopathic Medicine who conducted the work as a graduate student at University of California at Berkeley with scientist Sarah Werning.

The new study suggests another explanation: Dinosaurs grew fast but only lived three to four years in adulthood. Offspring were probably precocious, like calves or foals, Lee said......... Posted by: William      Read more         Source

January 10, 2008, 10:58 PM CT

A warming climate can support glacial ice

New research challenges the generally accepted belief that substantial ice sheets could not have existed on Earth during past super-warm climate events. The study by scientists at Scripps Institution of Oceanography at UC San Diego provides good evidence that a glacial ice cap, about half the size of the modern day glacial ice sheet, existed 91 million years ago during a period of intense global warming. This study offers valuable insight into current day climate conditions and the environmental mechanisms for global sea level rise.

The new study in the Jan. 11 issue of the journal Science titled, Isotopic Evidence for Glaciation During the Cretaceous Supergreenhouse, examines geochemical and sea level data retrieved from marine microfossils deposited on the ocean floor 91 million years ago during the Cretaceous Thermal Maximum. This extreme warming event in Earths history raised tropical ocean temperatures to 35-37C (95-98.6F), about 10C (50F) warmer than today, thus creating an intense greenhouse climate.

Using two independent isotopic techniques, scientists at Scripps Oceanography studied the microfossils to gather geochemical data on the growth and eventual melting of large Cretaceous ice sheets. The scientists compared stable isotopes of oxygen molecules (d18O) in bottom-dwelling and near-surface marine microfossils, known as foraminifera, to show that changes in ocean chemistry were consistent with the growth of an ice sheet. The second method in which an ocean surface temperature record was subtracted from the stable isotope record of surface ocean microfossils yielded the same conclusion......... Posted by: Tyler      Read more         Source

January 8, 2008, 9:32 PM CT

Ancient France Was A Jungle

Research on a treasure trove of amber has yielded evidence that France once was covered by a dense tropical rainforest with trees similar to those found in the modern-day Amazon. The 55-million-year-old pieces of amber was discovered in the Oise River area in northern France.

In the new study, Akino Jossang and his colleagues used laboratory instruments to analyze the fossilized tree sap in an effort to link specific samples of amber to specific kinds of trees. The amber remained intact over the ages, while the trees from which it oozed disappeared. Efforts to make such connections have been difficult because amber from different sites tended to have very similar chemical compositions.

The report describes discovery of a new organic compound in amber called "quesnoin," whose precursor exists only in sap produced by a tree currently growing only in Brazil's Amazon rainforest.

Scientists say that amber probably seeped out of a similar tree growing in a tropical forest that covered France millions of years ago before Earth's continents drifted into their current positions.

"The region corresponding to modern France could have been found in a geographically critical marshy zone belonging to Africa and a tropical zone 55 million years ago extending through North Africa to the Amazon," the report states......... Posted by: William      Read more         Source

January 3, 2008, 10:05 PM CT

Insect attack may have finished off dinosaurs

Asteroid impacts or massive volcanic flows might have occurred around the time dinosaurs became extinct, but a new book argues that the mightiest creatures the world has ever known may have been brought down by a tiny, much less dramatic force biting, disease-carrying insects.

An important contributor to the demise of the dinosaurs, experts say, could have been the rise and evolution of insects, particularly the slow-but-overwhelming threat posed by new disease carriers. And the evidence for this emerging threat has been captured in almost lifelike-detail a number of types of insects preserved in amber that date to the time when dinosaurs disappeared.

There are serious problems with the sudden impact theories of dinosaur extinction, not the least of which is that dinosaurs declined and disappeared over a period of hundreds of thousands, or even millions of years, said George Poinar Jr., a courtesy professor of zoology at Oregon State University. That time frame is just not consistent with the effects of an asteroid impact. But competition with insects, emerging new diseases and the spread of flowering plants over very long periods of time is perfectly compatible with everything we know about dinosaur extinction.

This concept is outlined in detail in What Bugged the Dinosaurs? Insects, Disease and Death in the Cretaceous, a book by George and Roberta Poinar, just published by Princeton University Press......... Posted by: William      Read more         Source

January 3, 2008, 10:00 PM CT

Explosive evolutionary events shaped early history

Researchers have known for some time that most major groups of complex animals appeared in the fossils record during the Cambrian Explosion, a seemingly rapid evolutionary event that occurred 542 million years ago. Now Virginia Tech paleontologists, using rigorous analytical methods, have identified another explosive evolutionary event that occurred about 33 million years earlier among macroscopic life forms uncorrelation to the Cambrian animals. They dubbed this earlier event the "Avalon Explosion".

The discovery, published in the January 4 issue of Science, suggests that more than one explosive evolutionary event may have taken place during the early evolution of animals.

The Cambrian explosion event refers to the sudden appearance of most animal groups in a geologically short time period between 542 and 520 million years ago, in the early Cambrian Period. Eventhough there were not as a number of animal species as in modern oceans, most (if not all) living animal groups were represented in the Cambrian oceans. "The explosive evolutionary pattern was a concern to Charles Darwin, because he expected that evolution happens at a slow and constant pace," said Shuhai Xiao, associate professor of geobiology at Virginia Tech. Darwins perception could be represented by an inverted cone with ever expanding morphological range, but the fossil record of the Cambrian Explosion and since is better represented by a cylinder with a morphological radiation at the base and morphological constraint afterwards......... Posted by: William      Read more         Source

December 20, 2007, 9:50 PM CT

Missing Link Between Whales and Four-Footed Ancestors

Researchers have discovered the missing link between whales and their four-footed ancestors. The result is reported in this week's issue of the journal Nature. The research is funded by the National Science Foundation (NSF).

Researchers since Darwin have known that whales are mammals whose ancestors walked on land. In the past 15 years, scientists led by Hans Thewissen of the Northeastern Ohio Universities Colleges of Medicine and Pharmacy (NEOUCOM) have identified a series of intermediate fossils documenting whale's dramatic evolutionary transition from land to sea.

But one step was missing: The identity of the land ancestors of whales.

Now Thewissen and his colleagues have discovered the skeleton of Indohyus, an approximately 48-million-year-old even-toed ungulate from the Kashmir region of India, as the closest known fossil relative of whales.

"The evolution of whales is a tale of the adaptation of a land-based mammal to increasingly aquatic environments," said H. Richard Lane, program director in NSF's Division of Earth Sciences. "This recent discovery provides us with a new understanding of this near-shore-dwelling, shallow-water ancestor".

Thewissen's team studied a layer of mudstone with hundreds of bones of Indohyus, a fox-sized mammal that looked something like a miniature deer. They report key similarities between whales and Indohyus in the skull and ear that show their close family relationship. They also explored how Indohyus lived and came up with some surprising results. They determined that the bones of the skeleton of Indohyus had a thick outside layer, much thicker than in other mammals of this size. This characteristic is often seen in mammals that are slow aquatic waders, such as the hippopotamus today......... Posted by: William      Read more         Source