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