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Exceptional whale fossil found in Egyptian desert

An American paleontologist and a team of Egyptians have found the most nearly complete fossilized skeleton of the primitive whale Basilosaurus isis in Egypt’s Western Desert, a university spokesman said on Monday. Philip Gingerich of the University of Michigan excavated the well-preserved skeleton, which is about 40 million years old, in a desert valley known as Wadi Hitan (the Valley of the Whales) southwest of Cairo, spokesman Karl Bates told Reuters. “His feeling is that it’s the most complete — the whole skeleton from stem to stern,” said Bates. The skeleton, which is 50 feet long, could throw light on why there are so many fossilized remains of whales and other ancient sea animals in Wadi Hitan and possibly how the extinct animal swam, he said.

Basilosaurus isis is one of the primitive whales known as archaeocetes, which evolved from land mammals and later evolved into the two types of modern whale. But it looks like a giant sea snake and the paleontologists who found the first archaeocetes thought they were reptiles. Modern whales swim by moving their horizontal fluke up and down in the water, while fish swim by lateral undulations. “The research team will use the new skeleton to study how it lived and swam, and possibly to learn why it so abundant in Wadi Hitan,” Gingerich said in a statement. The statement said the skeleton will go to Michigan for preservation and replication. The original will then come back to Egypt for display.

Wadi Hitan is unusually rich in fossil remains from the period, trapped in a sandstone formation that then formed the sea bed. The fossils include five species of whale, three species of sea cow, two crocodiles, several turtles, a sea snake, and large numbers of fossilized sharks and bony fish.
It is a protected area to be developed as a national park under an Italian-Egyptian cooperative program and it has been nominated as a UNESCO World Heritage site because of its natural beauty and scientific importance.

Yahoo
May 24, 2005

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Dinosaur eggs offer clues on reproduction

The rare discovery of eggs inside a dinosaur has given scientists new clues about the reproductive biology of the creatures and more support for the theory that birds came from dinosaurs. The pair of shelled eggs is the first of its kind found inside a dinosaur, said researchers who reported the discovery in Friday’s issue of the journal Science.

Scientists found the dinosaur produced eggs in some ways like a crocodile and in other ways like a bird. Crocodiles and similar primitive reptiles have two ovaries enabling them to lay a clutch of eggs. Birds have a single ovary and can only lay one egg at a time. The dinosaur’s egg-producing capability lay somewhere in between, suggesting a link with the modern bird, researchers said. It could produce more than one egg, but only one from each ovary at a time.

The theory that birds came from dinosaurs has been supported by many researchers, said Tamaki Sato of the Canadian Museum of Nature in Ottawa. But this latest research helps advance it, she added, calling it “strong evidence.” There have been previous findings of round objects around dinosaur skeletons and scientists have suspected they might be eggs but because they did not have shells, there wasn’t certainty, Sato said. “You have egg shells with this one,” she said of the specimen at the National Museum of Natural Science in Taiwan that was excavated from China. “This is the first time for sure.”

The scientists studied a dinosaur from a group of dinosaurs called oviraptorosaurians. This type of dinosaur — probably 10 feet to 13 feet long — is a subgroup of the theropods, thought to have been the ancestors to modern birds. The remains of the shelled eggs looked like pineapple-sized potatoes. The similar size of the eggs suggests the creature’s two oviducts each produced a single, shelled egg at the same time, the report said. Matt Carrano, curator of dinosaurs at the National Museum of Natural History in Washington, said the findings provide greater insights into the biology of the dinosaur and the evolution of birds. “It’s a window into a particular stage of evolution,” he said. “This particular dinosaur has characteristics that are birdlike but retains reptillian-like features.” “You have oviducts but they’re only doing one egg at time. Its biology is half way there between a bird and reptile.” Carrano also said it tells something about birds.

“The evolution of one egg at a time happened very early, before birds could fly, and then the evolution of only one oviduct happened later,” he said. “That might be related to the origin of flight,” he said, explaining that maybe birds wanted to lighten their body and so developed one oviduct.

Yahoo
April 26, 2005

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Okay, we give up

From the April 2005 Issue of Scientific American. There’s no easy way to admit this. For years, helpful letter writers told us to stick to science. They pointed out that science and politics don’t mix. They said we should be more balanced in our presentation of such issues as creationism, missile defense and global warming. We resisted their advice and pretended not to be stung by the accusations that the magazine should be renamed Unscientific American, or Scientific Unamerican, or even Unscientific Unamerican. But spring is in the air, and all of nature is turning over a new leaf, so there’s no better time to say: you were right, and we were wrong.

In retrospect, this magazine’s coverage of so called evolution has been hideously one-sided. For decades, we published articles in every issue that endorsed the ideas of Charles Darwin and his cronies. True, the theory of common descent through natural selection has been called the unifying concept for all of biology and one of the greatest scientific ideas of all time, but that was no excuse to be fanatics about it. Where were the answering articles presenting the powerful case for Canyon? Blame the scientists. They dazzled us with their fancy fossils, their radiocarbon dating and their tens of thousands of peer-reviewed journal articles. As editors, we had no business being persuaded by mountains of evidence.

Moreover, we shamefully mistreated the Intelligent Design (ID) theorists by lumping them in with creationists. Creationists believe that God designed all life, and that’s a somewhat religious idea. But ID theorists think that at unspecified times some unnamed super powerful entity designed life, or maybe just some species, or maybe just some of the stuff in cells. That’s what makes ID a superior scientific theory: it doesn’t get bogged down in details.

Good journalism values balance above all else. We owe it to our readers to present everybody’s ideas equally and not to ignore or discredit theories simply because they lack scientifically credible arguments or facts. Nor should we succumb to the easy mistake of thinking that scientists understand their fields better than, say, U.S. senators or best-selling novelists do. Indeed, if politicians or special-interest groups say things that seem untrue or misleading, our duty as journalists is to quote them without comment or contradiction. To do otherwise would be elitist and therefore wrong. In that spirit, we will end the practice of expressing our own views in this space: an editorial page is no place for opinions.

Get ready for a new Scientific American. No more discussions of how science should inform policy. If the government commits blindly to building an anti-ICBM defense system that can’t work as promised, that will waste tens of billions of taxpayers’ dollars and imperil national security, you won’t hear about it from us. If studies suggest that the administration’s antipollution measures would actually increase the dangerous particulates that people breathe during the next two decades, that’s not our concern. No more discussions of how policies affect science either so what if the budget for the National Science Foundation is slashed? This magazine will be dedicated purely to science, fair and balanced science, and not just the science that scientists say is science. And it will start on April Fools’ Day.

Source: MATT COLLINS

E-mail addres Scientific American
April 26, 2005

Original web page at Scientific American

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Blood vessels recovered from Tyrannosaurus rex bone

Palaeontologists have extracted soft, flexible structures that appear to be blood vessels from the bone of a Tyrannosaurus rex that died 68 million years ago. They also have found small red microstructures that resemble red blood cells. The discovery suggests biological information can be recovered from a wider range of fossil material than realised, which would greatly help the tracing of evolutionary relationships. The preservation found by the researchers is extraordinary – far better than traditionally expected in dinosaur bone. But that may be because researchers have not been looking hard enough at their finds. Mary Schweitzer at North Carolina State University, US, has also extracted similar soft structures from a few other dinosaur bones.

The leg bone came from a skeleton called B-rex found in a remote canyon in South Dakota, in 2000 by a member of Jack Horner’s research team at the Museum of the Rockies in Montana. The 107-centimetre-long femur – small for a T. rex – was intact when found, and its hollow interior had not been filled with minerals. That is unusual for a long-buried bone. However, with a protective plaster jacket built around it, the bone was too heavy for a helicopter to retrieve it from the remote site and it had to be broken in half. When Horner’s group split the bone, they carefully took samples for Schweitzer, then working at the Museum of the Rockies.

Bones are built by cells called osteocytes which are nourished by a rich fabric of blood vessels. The osteocytes secrete proteins which collect the calcium compounds that give bones their strength. To see what remained of this internal structure, Schweitzer soaked samples of the core of the bone in a solution that dissolved the calcium compounds. This left what she describes as “a flexible vascular tissue that demonstrates great elasticity and resilience”. For comparison, she then examined ostrich bones, as these birds are the largest and closest living relatives of T. rex. She found similar structures when she removed the calcium from the ostrich bones and treated the mixture with enzymes to break down collagen fibre in the bony matrix.

Other researchers have previously recovered traces of protein from dinosaur bones, and indeed just two weeks ago Schweitzer reported traces of protein in 70 million year old dinosaur eggs. “[The T. rex paper] suggests that biological and biochemical information might be recoverable from a wide range of fossil material,” says Angela Milner of the Natural History Museum, in London, UK, who has detected proteins in Iguanadon bone. “There certainly seem to be blood vessels,” she told New Scientist.

The next step will be to isolate proteins and try to sequence them. Comparing protein sequences could help trace relationships with other prehistoric beasts and with animals alive today. Schweitzer decline to discuss DNA because she does not work with it, but DNA is far less stable than proteins so is usually broken into fragments, even in tissue that has been frozen since the ice age.

Journal reference: Science (vol 307, p 1952)

New Scientist
April 12, 2005

Original web page at New Scientist

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Ancient crocodile found in Australia

A new species of crocodile which lived 40 million years ago has been discovered in tropical Australia, filling a gap in the evolution of the prehistoric-looking crocodile, researchers said on Thursday. Two nearly complete skulls and a lower jaw of a new species of crocodile that belonged to a group called Mekosuchinae were unearthed by miners in the northern state of Queensland, said Australia’s Monash University researcher Lucas Buchanan. “There is a big gap from about 30 to 60 million years ago of which we have no clue, except for these guys,” Buchanan told Reuters on Thursday.

Buchanan said the new species of crocodile was living in the early Tertiary period, from 65 million years ago until five million years ago, during which time climate change possibly had a major impact on the evolution of the modern-day crocodile. During the period, Australia and Antarctica broke apart and most of eastern Australia became warmer, leading to an increase in rainforests — an ideal environment for crocodiles. Buchanan said the new species of crocodile was very similar to the modern-day freshwater crocodile, suggesting the modern crocodile had changed little in millions of years of evolution.

“This croc would have looked much like a modern freshwater crocodile, which is the beautiful thing about crocodiles. They found something that works and stuck with it all through history,” he said. However, the ancient crocodile had sharper and laterally compressed teeth enabling it to sheer prey and an extra jaw muscle to give a stronger, more powerful bite. Buchanan said researchers were examining more crocodile fossils and hoped to add to the crocodile evolution puzzle. “It will also help us place this unique Australian group with the bigger picture of where they fit in with other lines of crocodiles,” he said.

Yahoo
March 15, 2005

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The oldest humans just got older — by 35,000 years

Two Homo sapiens skulls, originally dated as 130,000 years old when they were unearthed in Kibish, Ethiopia in 1967, then later put back to 160,000, have now been declared 195,000 years old based on geological evidence. “It pushes back the beginning of the anatomically modern humans,” said geologist Frank Brown, Dean of the University of Utah’s College of Mines and Earth Sciences and co-author of a new study into the skulls known as Omo I and Omo II.

The results of a study with New York’s Stony Brook University and the Australian National University were published in the science journal Nature. After looking at the volcanic ash where the skulls were found along the Omo river, the researchers not only dated the remains as the same age but pushed back the date of their existence, making them by far the oldest humans. “On this basis we suggest that hominid fossils Omo I and Omo II are relatively securely dated to 195 +/- 5 (thousand) years old … making Omo I and Omo II the oldest anatomically modern human fossils yet recovered,” the study concluded.

The new dating firmly underpins the “out of Africa” theory of the origin of modern humans. Brown said the redating was important culturally because it pushed back the known dawn of mankind, the record of which in most cases only starts 50,000 years ago. “Which would mean 150,000 years of Homo sapiens without cultural stuff such as evidence of eating fish, of harpoons, anything to do with music, needles, even tools,” he said. “This stuff all comes in very late except for stone knife blades, which appeared between 50,000 and 200,000 years ago, depending on whom you believe,” he added in a commentary.

The skulls were first discovered just 200 meters apart on the shores of what was formerly a lake by a team led by renowned fossil hunter and wildlife expert Richard Leakey. They bear cut marks made by stone tools which have been taken as evidence of prehistoric mortuary practices. Ever since the discovery of the fossil skulls, scientists have not only been locked in debate over the dating but also of the physical types because Omo I has more modern features than Omo II.

The new dating suggests that modern man and his older precursor existed side by side. “It dates the fossil record almost exactly concordant with the dates suggested by genetic studies for the origin of our species,” said Stony Brook anthropologist John Fleagle. “Second, it places the first appearance of modern Homo sapiens in Africa many more thousands of years before our species appears on any other continent. It lengthens the gap,” he added.

Yahoo
March 15, 2005

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The brain of Homo floresiensis

The brain of Homo floresiensis is assessed by comparing a virtual endocast from the type specimen (LB1) with endocasts from great apes, Homo erectus, Homo sapiens, a human pygmy, a human microcephalic, Sts 5 (Australopithecus africanus) and WT 17000 (Paranthropus aeithiopicus). Morphometric , allometric and shape data indicate that LB1 is not a microcephalic or pygmy. LB1’s brain size versus body size scales like an australopithecine, but its endocast shape resembles that of Homo erectus. LB1 has derived frontal and temporal lobes and a lunate sulcus in a derived position, which are consistent with capabilities for higher cognitive processing.

Science
March 15, 2005

Original web page at Science