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Posted on 08/13/2003 9:02:05 PM PDT by nwrep
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2 hours, 55 minutes ago
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By RAMOLA TALWAR BADAM, Associated Press Writer
BOMBAY, India - U.S. and Indian scientists said Wednesday they have discovered a new carnivorous dinosaur species in India after finding bones in the western part of the country.
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The new dinosaur species was named Rajasaurus narmadensis, or "Regal reptile from the Narmada," after the Narmada River region where the bones were found.
The dinosaurs were between 25-30 feet long, had a horn above their skulls, were relatively heavy and walked on two legs, scientists said. They preyed on long-necked herbivorous dinosaurs on the Indian subcontinent during the Cretaceous Period at the end of the dinosaur age, 65 million years ago.
"It's fabulous to be able to see this dinosaur which lived as the age of dinosaurs came to a close," said Paul Sereno, a paleontologist at the University of Chicago. "It was a significant predator that was related to species on continental Africa, Madagascar and South America."
Working with Indian scientists, Sereno and paleontologist Jeff Wilson of the University of Michigan reconstructed the dinosaur skull in a project funded partly by the National Geographic (news - web sites) Society.
A model of the assembled skull was presented Wednesday by the American scientists to their counterparts from Punjab University in northern India and the Geological Survey of India during a Bombay news conference.
Scientists said they hope the discovery will help explain the extinction of the dinosaurs and the shifting of the continents — how India separated from Africa, Madagascar, Australia and Antarctica and collided with Asia.
The dinosaur bones were discovered during the past 18 years by Indian scientists Suresh Srivastava of the Geological Survey of India and Ashok Sahni, a paleontologist at Punjab University.
When the bones were examined, "we realized we had a partial skeleton of an undiscovered species," Sereno said.
The scientists said they believe the Rajasaurus roamed the Southern Hemisphere land masses of present-day Madagascar, Africa and South America.
"People don't realize dinosaurs are the only large-bodied animal that lived, evolved and died at a time when all continents were united," Sereno said.
The cause of the dinosaurs' extinction is still debated by scientists. The Rajasaurus discovery may provide crucial clues, Sereno said.
India has seen quite a few paleontological discoveries recently.
In 1997, villagers discovered about 300 fossilized dinosaur eggs in Pisdura, 440 miles northeast of Bombay, that Indian scientists said were laid by four-legged, long-necked vegetarian creatures.
Indian scientists said the dinosaur embryos in the eggs may have suffocated during volcanic eruptions.
Why would you post a link to something you don't understand and cannot defend? How is that different than posting links to and excerpts from The Journal of Irreproducible Results or The Latvian Dating Guide? What is the point, except to load the thread with SPAM?
However, it is because of the prejudice associated with certain websites that I personally try to find third party sources (e.g. universities, professional journals, credible news organizations or government websites) so that the article stands a better chance of being read by the Lurkers.
It is downright amazing how many people are registered and post on Free Republic. Just imagine how many come by to read but don't post!
It is also interesting to see all the different professions represented here.
LOL! There almost is such a thing...
Okay, so "old earth" doesn't change your mind about the possibility of micro-evolution gradually resulting in macro-evolution. That still leaves the question of why? Given that micro-evolution happens, what mechanism prevents an enormous sequence of these little changes from accumulating?
I don't think ID guys like Behe borrow all that much from creationism. I'm not aware that he doubts old earth, or the value of radiometric dating, or the geologic column, or that he argues for the Flood, for example. He just doesn't see that evolution is the total answer. ID isn't a "middle of the road" position, so much as it tries to be an alternative to, or suppliment of evolution. Or so it seems to li'l ol' me.
The paper is at http://www.icr.org/research/icc03/pdf/Helium_ICC_7-22-03.pdf. It's been referenced previously on FR, and I have read it.
The creationists discuss three data sets. The first is an old Russian data set of radiation-damaged zircons, where they don't even know how to interpret the data. That's useless, and I'll ignore it. The second is the Nevada data of Reiners et al that I cited. From those data, Reiners obtained an activation energy, which roughly quantitates how easy it is for helium to diffuse. The higher the activation barrier, the slower the diffusions, and it's a very non-linear relationship. The activation energy is obtained using something called the Arrhenius equation, where you plot the natural log of the diffusion constant versus reciprocal temperature, and find the slope, which is the negative of the activation energy divided by the gas constant R. The guys who actually took the data - Reiners et al - claimed 44 kcal/mole. I extracted a slope from Figure 5 of the creationist paper, in which they reproduce Reiners et al's data, applied the usual Arrhenius equation, and got 43.5 kcal/mole, in agreement with the original authors. However, the creationists claim they get an activation energy of 34.4 kcal/mol, and go on to claim the data at the bottom part of the curve, where they have no quoted error, is as low as 29.4 kcal/mol! That's what they need for their young-earth model!
So, wondering why, I went to their appendix C - the report from the 'independent expert' which contains the results for the zircon data for which the creationists claim an activation energy of 34.4 kcal/mol. The expert says, and I quote "The first 14 steps lie on a linear array corresponding to an activation energy of ~ 46 kcal/mol and a closure temperature of ~183ºC assuming a cooling rate of 10ºC/Myr". That's in excellent agreement with Reiners et al! The much lower activation energy was obtained only when he temperature-cycled the zircons. He says the change might be due to temperature damage of the zircons by the experiment, or by anomalous retardation of helium release in the original sample. In either case, the slope that's relevant to helium retention over geological time is the original one, before the crystals has been altered by heating. The creationist's use without comment of the data from crystals that are temperature cycled, without acknowledging that without temperature cycling, the diffusion constants are orders of magnitude lower and in agreement with established work, looks to me like scientific fraud.
Now aren't you glad you baited me into giving the paper a more careful read?
Evolutionary Biology 3rd edition, by Douglas J. Futuyma
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