Petrified Velvet Worms From 425 Million Years Ago Reveal True Ecology Of Distant Past

Source:

http://www.sciencedaily.com/releases/2007/11/071126121836.htm

ScienceDaily (Nov. 26, 2007) — University of Leicester Geologist Dr Mark Purnell, with Canadian colleagues, reported, in the journal Geology, a new, exceptionally preserved deposit of fossils in 425 million year old Silurian rocks in Ontario.

The fossils include complete fish (only the second place on earth where whole fish of this age have been found), various shrimp and worm like creatures, including velvet-worms, which look (in Dr Purnell’s words) “rather like a dozen headless Michelin men dancing a conga.”
The velvet worms were deflated slightly by a little early rotting, but within days of dying these animals had been transformed to the mineral calcium phosphate. This preserved them as beautiful petrified fossils, showing the wonderful detail of their bodies, including coloured stripes. This Canadian deposit is unusual even for sites of exceptional preservation because it also includes normal shelly fossils. From this it is possible to be sure that the conditions in which all the animals were living were not much different to normal nearshore seas of the Silurian period.
Dr Purnell commented: “It provides us with our best view of what lived together in such environments 425 million years ago, and our best information for understanding how life on earth at that time was different to today.
“If people think of a fossil, they will undoubtedly be thinking of something with a hard skeleton or shell of some sort, and it is true that the vast majority of fossil are what in today’s world we call sea shells. But imagine trying to understand the biodiversity and ecology of a submarine seaside ecosystem with only the remains of sea shells to go on.
“All the variety of worms that crawl over and into the sand would be unknown, as would all the shrimpy things that scurry over the surface. We would have only a very partial view of the real biological picture.
“This is what palaeontologists are faced with when they try to reconstruct the history and past ecology of life on Earth, because everything without a shell very quickly, within hours or days, rots away to nothing, leaving no trace that it ever existed.”
Fortunately, there are a few special rock deposits scattered around the world that preserve fossilised traces of those things that normally rot away. These are known to palaeontologists as sites of exceptional preservation, but they are, Dr Purnell says, tricky to interpret precisely because they are exceptional.
“They require very unusual environmental conditions in order to slow down the decomposition of soft tissues, such as muscle and skin, and rapidly transform them into geologically stable minerals that will survive as fossils for millions of years.
“The difficulty for geologists has been that if the conditions are exceptionally unusual, is that also true of the preserved fauna or is it a more typical example? That is something our latest find has helped resolve.”
Adapted from materials provided by University of Leicester.

Fausto Intilla

www.oloscience.com

Giant Fossil Sea Scorpion Bigger Than Man

Source:

http://www.sciencedaily.com/releases/2007/11/071120195710.htm

ScienceDaily (Nov. 21, 2007) — The discovery of a giant fossilised claw from an ancient sea scorpion indicates that when alive it would have been about two and a half meters long, much taller than the average man.

This find, from rocks 390 million years old, suggests that spiders, insects, crabs and similar creatures were much larger in the past than previously thought.
Dr Simon Braddy from the Department of Earth Sciences at the University of Bristol, co-author of an article about the find, said, 'This is an amazing discovery. We have known for some time that the fossil record yields monster millipedes, super-sized scorpions, colossal cockroaches, and jumbo dragonflies, but we never realised, until now, just how big some of these ancient creepy-crawlies were.'
The claw was discovered by one of Dr Braddy's co-authors*, Markus Poschmann, in a quarry near Prüm in Germany.
Poschmann described finding the fossil: "I was loosening pieces of rock with a hammer and chisel when I suddenly realised there was a dark patch of organic matter on a freshly removed slab. After some cleaning I could identify this as a small part of a large claw. Although I did not know if it was more complete or not, I decided to try and get it out. The pieces had to be cleaned separately, dried, and then glued back together. It was then put into a white plaster jacket to stabilise it."
The claw is from a sea scorpion (eurypterid) Jaekelopterus rhenaniae that lived between 460 and 255 million years ago. It is 46 centimetres long, indicating that the sea scorpion to which it belonged was around 2.5 metres (8 feet) long -- almost half a metre longer than previous estimates for these arthropods and the largest one ever to have evolved.
Eurypterids are believed to be the extinct aquatic ancestors of scorpions and possibly all arachnids.
Some geologists believe that giant arthropods evolved due to higher levels of oxygen in the atmosphere in the past. Others, that they evolved in an 'arms race' alongside their likely prey, the early armoured fish.
'There is no simple single explanation', explains Braddy. 'It is more likely that some ancient arthropods were big because there was little competition from the vertebrates, as we see today. If the amount of oxygen in the atmosphere suddenly increased, it doesn't mean all the bugs would get bigger.'
*The research is published online in the Royal Society's journal Biology Letters.
Adapted from materials provided by University of Bristol.

Fausto Intilla

www.oloscience.com

Maya Politics Likely Played Role In Ancient Large-game Decline

Source:

http://www.sciencedaily.com/releases/2007/11/071114200920.htm

ScienceDaily (Nov. 20, 2007) — A University of Florida study is the first to document ancient hunting effects on large-game species in the Maya lowlands of Central America, and shows political and social demands near important cities likely contributed to their population decline, especially white-tailed deer.

Additional evidence from Maya culture and social structure at the end of the Classic period (approximately 250 to 800 A.D) strongly supports this assertion.
“We’re finding declines specifically in large-game species, and particularly in the species that were politically and socially important to the Maya,” Emery said. “The politically powerful elite Maya had preferential access to large game, and white-tailed deer were especially important to the Maya as food and for their symbolic power.”
Emery tracked the proportion of large-game animals to all vertebrate species over time, using 78,928 animal bones found at 25 Maya archaeological sites. To tease apart specific hunting effects, she also tracked the proportion of white-tailed deer to all vertebrates. Her samples spanned 2,500 years, from about 1000 B.C. to 1500 A.D.
This period includes the collapse of the lowland Maya political and social order and the final period of Spanish colonization. Her study, funded by the National Science Foundation, is the first regional analysis of this area to interpret how humans impacted animal populations based on archaeological data of animal use by humans. She used both her own original data and existing published data.
“The data suggests the game decline was caused primarily by hunting pressure since the reduction in numbers was recorded for large vertebrates as opposed to just animals sensitive to the disappearance of forest cover or those sensitive to climate changes,” Emery said. “But the effects of hunting pressure were undoubtedly exacerbated by deforestation and climate change since there is also documented evidence for these changes at the same time.”
Emery said not all sites showed large-game declines despite high human population, and that the declines were most noticeable at regional capitals and large cities.
“The capital cities were home to a large and top-heavy ruling class who demanded that the regions’ hunters provide them with large quantities of the best cuts of favorite meats from large game, and particularly the white-tailed deer,” Emery said. “They also demanded large numbers of symbolically important species such as white-tailed deer and large wild cats like jaguar and puma, since these species were used as symbolic displays of their wealth and power, and were used in ritual interactions with the deities.”
Deer also were important theatrically because actors wore costumes to portray the predator-prey relationship.
The power of the noble classes and the king was based on their perceived abilities to control ecology, but Emery said several negative environmental situations converged simultaneously, likely contributing to the collapse of Maya political stability starting around 1,200 years ago. According to current Maya archaeological theory, Maya demand for wood used in building finishes such as lime plaster combined with an exploding population base that cleared more and more land for agriculture — resulting in deforestation. Concurrent climate change resulted in a 200-year drought which further curtailed forest regrowth.
“The rulers’ response to the environmental degradation may have been to demand more large game and more deer to use in feasts and rituals where they appealed to deities for help and also to prove their status,” Emery said. “As the valued resources became more scarce, they made more demands to obtain them to prove and reinforce their power.”
Their demand for large game was not extreme enough to cause extinction or local exterminations, an important finding. Emery said this indicates that over the 2,500 years of this study, the ancient Maya were generally careful of their animal resources.
Brown University ancient Maya scholar Stephen Houston said Emery’s “breadth of expertise” allowed her to tackle such an important review of Maya animal use.
“The lack of extinctions shows that the Maya impact on parts of their environment was not as profound as some have thought,” Houston said. “That is, we don’t see utter devastation to the extent that species disappeared entirely. But Emery also confirms that the Maya went after high-value, prestigious meats like deer and, through vigorous hunting, that they found such game harder and harder to find.”
The study by Florida Museum of Natural History Assistant Curator of Environmental Archaeology Kitty Emery appears in the Oct. 31 issue of the Journal for Nature Conservation.
Adapted from materials provided by University of Florida.

Fausto Intilla

www.oloscience.com

Dinosaur From Sahara Ate Like A 'Mesozoic Cow'

Source:

http://www.sciencedaily.com/releases/2007/11/071115113252.htm

ScienceDaily (Nov. 16, 2007) — A 110-million-year-old dinosaur that had a mouth that worked like a vacuum cleaner, hundreds of tiny teeth and nearly translucent skull bones has been discovered.

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.
The dinosaur's oddest feature was a broad, straight-edged muzzle, which allowed its mouth to work close to the ground. Unlike any other plant eater, Nigersaurus had more than 50 columns of teeth, all lined up tightly along the front edge of its squared-off jaw, forming, in effect, a foot-long pair of scissors.
A CT scan of the jaw bones showed up to nine "replacements" stacked behind each cutting tooth, so that when one wore out, another immediately took its place. There were more than 500 teeth in total, with a new tooth in each column joining the scissors edge every month. "Among dinosaurs," Sereno said, "Nigersaurus sets the Guinness record for tooth replacement."
Sereno and coauthors write in PLoS One that Nigersaurus' downwardly deflected muzzle may characterize most diplodocoids, such as North America's Diplodocus. "Some of these unusual sauropods thrived to become the pre-eminent ground-level feeders of the Mesozoic," said coauthor Jeffrey Wilson, assistant professor at the University of Michigan.
CT scanning allowed Sereno and team to look inside the dinosaur's braincase. There, small canals of the brain's balancing organ revealed the habitual pose of the head. Reconstructed from CT scans, these canals showed that the muzzle of Nigersaurus angled directly toward the ground, unlike the forward-pointing snouts of most other dinosaurs. This feature, along with unusual wear facets on the animal's teeth, led Sereno and colleagues to conclude that Nigersaurus largely fed by cropping plants near the ground.
Coauthor Lawrence Witmer, professor at Ohio University, who imaged the brain and organ of equilibrium, said, "What we have here is the first good look at a sauropod brain, and it has important things to say about this animal's posture and behavior."
Jaw design was not Nigersaurus' only odd characteristic: It had a backbone that was more air than bone. "The vertebrae are so paper-thin that it is difficult to imagine them coping with the stresses of everyday use -- but we know they did it, and they did it well," said Wilson, who was an expedition team member.
The first bones of Nigersaurus were picked up in the 1950s by French paleontologists, though the species was not named. Sereno and his team honored this early work by naming the species after French paleontologist Philippe Taquet. Sereno's team member Didier Dutheil first spotted the skull bones of Nigersaurus in 1997, and on that expedition and the next, teams collected about 80 percent of the skeleton.
The fossil area, in the present-day nation of Niger, was home to the enormous extinct crocodilian nicknamed SuperCroc as well as the likely fish eater Suchomimus, both found by Sereno and both on the prowl for Nigersaurus some 110 million years ago. Then, the African continent was just beginning to free itself of land connections it inherited as a central part of the ancient supercontinent Pangaea. Nigersaurus' closest relative has been found recently in Spain.
Coauthors on the PLoS One paper include Jeffrey A. Wilson, Lawrence M. Witmer, John A. Whitlock, Abdoulaye Maga, Oumarou Ide and Timothy A. Rowe. Funders of the research in addition to the National Geographic Society include The David and Lucile Packard Foundation, the Pritzker Foundation and the Women's Board of the University of Chicago.
Citation: Sereno PC, Wilson JA, Witmer LM, Whitlock JA, Maga A, et al (2007) Structural Extremes in a Cretaceous Dinosaur. PLoS One 2(11): e1230.doi:10.1371/journal.pone.0001230
Details of the dinosaur's 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 the December 2007 issue of National Geographic magazine, "Extreme Dinosaurs."
Sereno's research was partly funded by the National Geographic Society.
Adapted from materials provided by Public Library of Science.

Fausto Intilla

www.oloscience.com

More Than Just a Pretty Face From History

Source:

http://www.nytimes.com/2007/11/11/weekinreview/11wilford.html?ref=science

By JOHN NOBLE WILFORD
Published: November 11, 2007

The first public showing of the face of the boy pharaoh Tutankhamun, last week, exposed more than cracked, leathery skin and his buckteeth. (Gene Tierney’s overbite was much more fetching.) Archaeologists also detected a new feature, the hint of a Tut smile, transfiguring a regal mummy from antiquity into a human being with emotions perhaps like those of people today. The first reaction of Zahi Hawass, Egypt’s head of antiquities, was unscientific. The face, he said, “has magic; it has mystery; it has beauty.”
The search for identifiable affinities, if only a smile, with people long ago may account for our fascination with mummies and hominid skulls. History is full of dynasties and armies, documents and artifacts, but lacks, especially in deep time, the flesh and sinew of shared humanity. There is some felt need to put a face on the past.
Even ancient Egypt, which left arguably the most expressive remains of an early civilization, has frustrated scholars. Its temples and tombs are decorated with sculpture, portraits and other paintings. But the art is more or less idealized. Though the faces may bear some likeness to the person in life, the stylized renderings speak to posterity, conveying the divinity and serenity of immortal kings and queens.
Some representations lead to contradictory impressions. A famous bust of the powerful queen Nefertiti shows a beautiful swanlike neck and high cheek bones. In others, she appears haggard. Even Nefertiti must have had bad days.
Emily Teeter, an Egyptologist at the University of Chicago, said that when you had the body of a person and could also look into the face, then some of the personality may emerge. This, she said, “goes beyond representational art and really conceptualizes history.”
Tut’s unwrapped remains, previously seen by only a small number of people, will now be on display to the public, in a climate-controlled glass case in his tomb. A few other mummified royal faces are also well preserved. Matthew Adams, an Egyptologist at the Institute of Fine Arts of New York University, said the character of Seti I, the pharaoh from the 13th century B.C. who was father of Ramses II, seemed written in his noble visage. “People have been influenced by that face in their interpretation of Seti as having been a good, wise king,” he said. “We are really projecting our own esthetic on him.”
In the United States, where history is more recent, the past is more reliably evoked through portraits and photography. See Washington’s set jaw and think of resolute leadership, not to mention those ill-fitting dentures. Look upon Lincoln’s craggy, brooding face and realize something of the burden he bore in a country divided. They are reminders of how much of remote antiquity is unrecoverable.
An enigmatic smile may be as close as people today will ever get to knowing the boy pharaoh who reigned 3,300 years ago and died at 19. The bare bones of the hominid Lucy are expressionless. Cleopatra, who charmed the powerful, remains a mystery; coins that show her large, unattractive nose call into question her reputation for beauty.
And who would not give their last drachma for a look at Helen of Troy, whose face launched a thousand ships?

Fausto Intilla

www.oloscience.com

Cultic City And Fortress Unearthed In Southern Turkey

Source:

http://www.sciencedaily.com/releases/2007/10/071030133030.htm

ScienceDaily (Nov. 5, 2007) — New excavations conducted by the University of Tübingen (Germany) and the Onsekiz Mart University of Çanakkale (Turkey) at the site of Sirkeli Höyük near Adana (southern Turkey) have revealed the remains of a massive bastion fortification dating to the Hittite Imperial Period (ca. 1300 BC). Sirkeli Höyük, one of the largest settlement mounds in Cilicia during the Bronze- and Iron Ages, was already known to archaeologists and historians because of two Hittite rock reliefs located at the site.

The better preserved rock relief of the two shows the Hittite King Muwatalli II (ca. 1290–1272 BC), opponent of Pharaoh Ramesses II in the famous Battle of Qadesh in Syria and is thus the oldest Hittite rock relief known so far.
On the upside of the rock, just above the reliefs, various shallow pits or basins are found which apparently are to be connected with the reliefs and were used for libations in the course of cultic activities.
These pits were part of a larger cultic installation which also included a building to the west of the rock reliefs. This ensemble is thought to be a cultic installation for the Hittite King.
Excavations at the site were conducted between 1992-1997 by the Universities of Munich and Innsbruck. In 2006 excavations were resumed by the University of Tübingen and the University of Çanakkale. The project and its organization are based at the Institute of Near Eastern Archaeology and Assyriology at the University of Tübingen. The Institute of Prehistorical Archaeology and the Institute of Classical Archaeology are associated with the project.
At the University of Çanakkale the project is based at the Institute of Prehistorical Archaeology, Near Eastern Archaeology and Classical Archaeology. The project is carried out under the patronage of the Bavarian Academy of Sciences.
In the course of the first two campaigns conducted in 2006 and 2007 the massive fortification bastion in the north-western part of the city was excavated. Finds made within the complex show that the building was constructed during the Late Bronze Age (1500-1200 B.C.) and apparently modified and re-used during the Iron Age (1200-600 B.C.). Later, the surrounding area of the mound was occupied by Hellenistic buildings. The finds reveal that the site was engaged in cultural exchange and trade with the Levant, the Aegean and different regions of Anatolia in the 2nd and 1st millennium B.C.
The site of Sirkeli Höyük may possibly also be identified with the ancient cultic city of Lawazantiya which is known to have been the home town of Hittite Queen Puduhepa, wife of King Hattusili III (ca. 1265-1240 B.C.).
Adapted from materials provided by Tuebingen University.

Fausto Intilla

www.oloscience.com