December 10, 2007, 9:17 PM CT

Massive dinosaur discovered in Antarctica

A new genus and species of dinosaur from the Early Jurassic has been discovered in Antarctica. The massive plant-eating primitive sauropodomorph is called Glacialisaurus hammeri and lived about 190 million years ago.

The recently published description of the new dinosaur is based on partial foot, leg and ankle bones found on Mt. Kirkpatrick near the Beardmore Glacier in Antarctica at an elevation of more than 13,000 feet.

The fossils were painstakingly removed from the ice and rock using jackhammers, rock saws and chisels under extremely difficult conditions over the course of two field seasons, said Nathan Smith, a graduate student at The Field Museum. They are important because they help to establish that primitive sauropodomorph dinosaurs were more broadly distributed than previously thought, and that they coexisted with their cousins, the true sauropods.

The findings were published online Dec. 5 in the Acta Palaeontologica Poloncica (see http://www.app.pan.pl/). Diego Pol, a paleontologist at the Museo Paleontolgico Egidio Feruglio in Chubut, Argentina, is the other co-author of the research.

Sauropodomorph dinosaurs were the largest animals to ever walk the earth. They were long-necked herbivores and include Diplodocus and Apatosaurus. Their sister group is the theropods, which include Tyrannosaurus, Velociraptor, and modern birds......... Posted by: William      Read more         Source

December 4, 2007, 10:28 PM CT

Rapid Maturation In A Neanderthal Child

An international European research collaboration led by researchers at the Max Planck Institute for Evolutionary Anthropology reports evidence for a rapid developmental pattern in a 100,000 year old Belgian Neanderthal (Homo neanderthalensis). The report, published in Proceedings of the National Academy of Sciences USA (online edition early December), details how the team used growth lines both inside and on the surfaces of the child's teeth to reconstruct tooth formation time and its' age at death. Researchers found differences in the duration of tooth growth in the Neanderthal when in comparison to modern humans, with the former showing shorter times in most cases. This faster growth resulted in a more advanced pattern of dental development than in fossil and living members of our own species (Homo sapiens). The Scladina juvenile, which appears to be developmentally similar to a 10-12 year old human, was estimated to be in fact about 8 years old at death. This pattern of development appears to be intermediate between early members of our genus (e.g., Homo erectus) and living people, suggesting that the characteristically slow development and long childhood is a recent condition unique to our own species.

Neanderthal life history, or the timing of developmental and reproductive events, has been under great debate during the past few decades. Across primates, tooth development, specifically the age of molar eruption, is correlation to other developmental landmarks such as weaning and first reproduction. Researchers have previously found evidence to both support and refute the idea that Neanderthals grew up differently than our own species. In this new study, scientists used information from the inside of a molar tooth, coupled with data from micro-computed tomography (micro-CT), as well as evidence of developmental stress on the outsides of tooth crowns and roots. This yields the first chronology, or time sequence, for Neanderthal tooth growth, which differs from living humans. The Scladina Neanderthal grew teeth over a shorter period of time, and has more teeth erupted (present in the mouth), than similarly-aged fossil or living humans (Homo sapiens). This suggests that other aspects of physical development were likely more rapidly achieved as well, implying significant differences in the behaviour or social organization of these ancient humans......... Posted by: William      Read more         Source

November 26, 2007, 9:47 PM CT

Single main migration across Bering Strait

Did a relatively small number of people from Siberia who trekked across a Bering Strait land bridge some 12,000 years ago give rise to the native peoples of North and South America?.

Or did the ancestors of todays native peoples come from other parts of Asia or Polynesia, arriving multiple times at several places on the two continents, by sea as well as by land, in successive migrations that began as early as 30,000 years ago?.

The questions featured on magazine covers and TV specials have agitated anthropologists, archaeologists and others for decades.

University of Michigan scientists, working with an international team of geneticists and anthropologists, have produced new genetic evidence thats likely to hearten proponents of the land bridge theory. The study, published online in PLoS Genetics, is one of the most comprehensive analyses so far among efforts to use genetic data to shed light on the topic.

The scientists examined genetic variation at 678 key locations or markers in the DNA of present-day members of 29 Native American populations across North, Central and South America. They also analyzed data from two Siberian groups. The analysis shows:

o genetic diversity, as well as genetic similarity to the Siberian groups, decreases the farther a native population is from the Bering Strait adding to existing archaeological and genetic evidence that the ancestors of native North and South Americans came by the northwest route......... Posted by: William      Read more         Source

November 21, 2007, 5:09 AM CT

Digging biblical history, or the end of the world

Some come to dig the Tel Aviv University-directed archeological site at Tel Megiddo because they are enchanted by ancient stories of King Solomon. Others come because they believe in a New Testament prophecy that the mound of dirt will be the location of a future Judgment Day apocalyptic battle. Hence the second, rather more chilling name for the site: "Armageddon".

Tel Megiddo has been the subject of many decisive battles in ancient times (among the Egyptian, Hebrew and Assyrian peoples) and today it holds a venerated place in archaeology, explains site co-director and world-renowned archeologist Prof. Israel Finkelstein.

Says Prof. Finkelstein, from the Department of Archaeology and Ancient Near Eastern Cultures at Tel Aviv University, "Megiddo is one of the most interesting sites in the world for the excavation of biblical remains. Now volunteers and students from around the world can participate in the dig which lets them uncover 3,000 years worth of history -- from the late 4th millennium B.C.E. to the middle of the first millennium C.E."

Prof. Finkelstein, who belongs to the Sonia and Marco Nadler Institute of Archaeology at Tel Aviv University, has been co-directing the site with Prof. David Ussishkin, also of Tel Aviv University, since 1994......... Posted by: William      Read more         Source

November 19, 2007, 8:43 PM CT

The Earliest Chocolate Drink Of The New World

The earliest known use of cacao--the source of our modern day chocolate--has been pushed back more than 500 years, to somewhere between 1400 and 1100 B.C.E., thanks to new chemical analyses of residues extracted from pottery excavated at an archaeological site at Puerto Escondido in Honduras. The new evidence also indicates that, long before the flavor of the cacao seed (or bean) became popular, it was the sweet pulp of the chocolate fruit, used in making a fermented (5% alcohol) beverage, which first drew attention to the plant in the Americas.

That cacao's popularity on the world stage began with its role in an alcoholic beverage does not surprise archaeochemist Dr. Patrick McGovern, Senior Research Scientist, Museum Applied Science Center for Archaeology (MASCA) at the University of Pennsylvania Museum of Archaeology and Anthropology and one of five authors of the scientific research article on the discovery ("Chemical and archaeological evidence for the earliest cacao beverages," by John S. Henderson, Rosemary A. Joyce, Gretchen R. Hall, W. Jeffrey Hurst, and Patrick E. McGovern) would be published on-line in Early Edition the week of Nov. 12 http://www.pnas.org/ and in the November 27, 2007 print issue of PNAS USA (pp. 18937-18940, Issue 48, Volume 104).

"This development probably provided the impetus to domesticate the chocolate tree and only later, to prepare a beverage based on the more bitter beans," suggested Dr. McGovern. "An alcoholic beverage from the pulp, carrying on this ancient tradition, continues to be made in parts of Latin America"......... Posted by: William      Read more         Source

November 15, 2007, 10:32 PM CT

Dinosaur from Sahara ate like a 'mesozoic cow'

110 million-year-old dinosaur that had a mouth that worked like a vacuum cleaner, hundreds of tiny teeth and nearly translucent skull bones will be unveiled Thursday, Nov. 15, at the National Geographic Society.

Found in the Sahara by National Geographic Explorer-in-Residence Paul Sereno, paleontologist and professor at the University of Chicago, the dinosaur is a plant eater known as Nigersaurus taqueti. Originally named by Sereno and his team in 1999 with only a few of its distinctive bones in hand, Nigersaurus has emerged as an anatomically bizarre dinosaur.

Nigersaurus, a younger cousin of the more familiar North American dinosaur Diplodocus, is small for a sauropod, measuring only 30 feet in length. It managed to sustain its elephant-sized body with a featherweight skull armed with hundreds of needle-shaped teeth, said Sereno. Barely able to lift its head above its back, Nigersaurus operated more like a Mesozoic cow than a reptilian giraffe, mowing down mouthfuls of greenery that consisted largely of ferns and horsetails.

Details of the dinosaurs anatomy and lifestyle will be published Nov. 21, 2007, (available Nov. 15) in PLoS ONE, the online journal from the Public Library of Science, as well as in a cover article in the December 2007 issue of National Geographic magazine, Extreme Dinosaurs......... Posted by: William      Read more         Source

November 14, 2007, 8:50 PM CT

Fire, ice, and invasion

Special Issue of Frontiers in Ecology and the Environment focuses on paleoecology, which uses fossilized remains and soil and sediment cores to reconstruct past ecosystems.

Some researchers argue that the pre-Columbian Amazon was pristine, with indigenous people living in harmony with nature. Others suggest that the Amazon is a manufactured landscape, altered by and disturbed by human activities even before the arrival of Europeans. In Amazonian exploitation revisited: ecological asymmetry and the policy pendulum, Mark Bush (Florida Institute of Technology) and Miles Silman (Wake Forest University) discuss this debate.

Bush and Silman present paleodata from fossil pollen and charcoal in soil cores that support both perspectives. They argue that in some areas of the Amazon, human impact was extreme, particularly on bluffs around rivers. Yet they also found vast stretches of the forest where human influence was minimal. If widespread disturbance was typical in the Amazon forest until just 500 years ago, that suggests the ecosystem is resilient to human activities, including logging. However, as the authors demonstrate, the manufactured landscape argument only holds true for localized patches of forest, and should not be used as a basis for management of the Amazon as a whole......... Posted by: William      Read more         Source

November 13, 2007, 9:35 PM CT

Ice age imprint found on cod DNA

An international team of researchers, led by the University of Sheffield, has demonstrated how Atlantic cod responded to past natural climate extremes. The new research could help in determining cods vulnerability to future global warming.

With fishing pressures high and stock size low, there is already major concern over the current sustainability of cod and other fisheries. The new findings, reported in the journal, Proceedings of the Royal Society B, show that natural climate change has previously reduced the range of cod to around a fifth of what it is today, but despite this, cod continued to populate both sides of the North Atlantic.

The scientists used a computer model and DNA techniques to estimate where cod could be found in the ice age, when colder temperatures and lower sea-levels caused the extinction of some populations and the isolation of others.

The computer models used to estimate ice-age habitats suitable for cod were developed by Professor Grant Bigg, Head of the University of Sheffields Department of Geography. These climatic analyses were combined with genetic studies by US scientists at Duke University and the University of California, and ecological information prepared by colleagues at the University of East Anglia and the Institute of Marine Research in Norway......... Posted by: William      Read more         Source

November 12, 2007, 9:49 PM CT

Human ancestors: more gatherers than hunters?

Chimpanzees crave roots and tubers even when food is plentiful above ground, as per a new study that raises questions about the relative importance of meat for brain evolution.

Appearing online the week of Nov. 12 in the early edition of the Proceedings of the National Academy of Sciences, the study documents a novel use of tools by chimps to dig for tubers and roots in the savanna woodlands of western Tanzania.

The chimps eagerness for buried treats offers new insights in an ongoing debate about the role of meat versus potato-like foods in the diet of our hominid ancestors, said first author Adriana Hernandez-Aguilar, who collected the field data for her doctoral research at the University of Southern California.

The debate centers on the diet followed by early hominids as their brain and body size slowly increased towards a human level. Was it meat-and-potatoes, or potatoes-and-meat".

Some scientists have suggested that what made us human was actually the tubers, Hernandez-Aguilar said.

Anthropologists had speculated that roots and tubers were mere fallback foods for hominids trying to survive the harsh dry season in the savanna 3.5 million years ago and later (hominids are known to have consumed meat at least as early as 2.5 million years ago)......... Posted by: William      Read more         Source

October 31, 2007, 5:13 AM CT

Dinosaur Deaths Outsourced to India?

A series of monumental volcanic eruptions in India may have killed the dinosaurs 65 million years ago, not a meteor impact in the Gulf of Mexico. The eruptions, which created the gigantic Deccan Traps lava beds of India, are now the prime suspect in the most famous and persistent paleontological murder mystery, say researchers who have conducted a slew of new investigations honing down eruption timing.

"It's the first time we can directly link the main phase of the Deccan Traps to the mass extinction," said Princeton University paleontologist Gerta Keller. The main phase of the Deccan eruptions spewed 80 percent of the lava which spread out for hundreds of miles. It is calculated to have released ten times more climate altering gases into the atmosphere than the nearly concurrent Chicxulub meteor impact, as per volcanologist Vincent Courtillot from the Physique du Globe de Paris.

Keller's crucial link between the eruption and the mass extinction comes in the form of microscopic marine fossils that are known to have evolved immediately after the mysterious mass extinction event. The same telltale fossilized planktonic foraminifera were found at Rajahmundry near the Bay of Bengal, about 1000 kilometers from the center of the Deccan Traps near Mumbai. At Rajahmundry there are two lava "traps" containing four layers of lava each. Between the traps are about nine meters of marine sediments. Those sediments just above the lower trap, which was the mammoth main phase, contain the incriminating microfossils......... Posted by: William      Read more         Source