New Dinosaur Raptor Found; First In Southern Hemisphere
Columbus OH (SPX) Feb 28, 2005
Scientists at Ohio State University and the Argentine Museum of Natural History have identified a new species of raptor dinosaur from fossils found in Patagonia the very southern tip of South America.
It is the first raptor ever found in the Southern Hemisphere, but compared to other raptors, Neuquenraptor argentinus wasn't much of a standout. It was only of average height and weight for its kind, measured six feet from head to tail, and brandished a razor-sharp claw for slashing prey.
Now, its bones provide the first uncontroversial evidence that raptors roamed the prehistoric world beyond the Northern Hemisphere 90 million years ago, said Diego Pol, a postdoctoral researcher at Ohio State. Before this, the extent of the dinosaurs range wasnt certain.
Pol and Fernando Novas of the Argentine Museum of Natural History published their finding in the current issue of the journal Nature.
With joint appointments in Ohio State's Mathematical Biosciences Institute and the Department of Biomedical Informatics, Pol represents a kind of new species himself. He is one of a growing number of scientists who are using todays powerful computers to confront grand challenges in the life sciences.
He spends most of his time developing software to map the genes of living creatures, from bacteria to humans, to show how different species are related.
He used similar techniques to study the relationships of the new raptor. Because fossils don't preserve DNA, Pol mapped the dinosaur's anatomical and skeletal characteristics to place it on the raptor family tree.
Novas discovered the fossils in Patagonia with colleague Pablo Puerta in 1996. They found fragments of the dinosaur's vertebrae and ribs, as well as parts of its legs and a left rear foot, complete with the signature raptor claw.
Since then, scientists from around the world have worked to record all the data that could be used to identify the dinosaur, such as the size and shape of its bones and where the muscles and ligaments connected to them. All in all, they measured 224 separate characteristics.
That may sound like a lot of information, but Pol is accustomed to working with much larger data sets. He routinely assembles family trees based on genetic sequences that number in the thousands.
He's working with experts in the Department of Biomedical Informatics, the Ohio Supercomputer Center, and the University of Tucuman in Argentina to develop software to sort through those mammoth databases and find connections between species.
"We can use gene sequences, or any physical characteristic like bones or muscles, or even behavior. We find the tree structure that is most compatible with whatever data we have," Pol said.
Once Pol entered the dinosaur data into the software, the final analysis took only minutes. The conclusion: the bones definitely belonged to a raptor.
Not only the claw, but also finer details such as the pointed shape of some of the foot bones provided key proof, he explained.
Neuquenraptor lived 90 million years ago, during the late Cretaceous period - roughly the same time that the Velociraptor of Jurassic Park fame and its cousin Utahraptor roamed what are now Asia and North America. And thats what makes Neuquenraptor so special.
According to current geologic theory, the Earth of 90 million years ago featured two giant supercontinents - one called Laurasia that eventually split into Europe, Asia, and North America, and another called Gondwana that became Australia, Africa, Antarctica, and South America.
Because Neuquenraptor was found in Patagonia, it must have lived on Gondwana, Pol said. All other verified species of raptor have been found on land that was once Laurasia.
"That's what was most striking," Pol said. "Given the geographic location, you wouldn't expect to find a raptor there. So from the beginning we knew we had an interesting finding."
Since Gondwana and Laurasia were completely separated by ocean 90 million years ago, the find suggests that a common raptor ancestor probably roamed both supercontinents before they split apart from an even larger land mass, Pangea - some 150 million years ago, during the late Jurassic period.
"Up to now, all known raptor species were exclusive to the Northern Hemisphere," Pol said. "And they all date to a time way after the splitting of the two land masses."
Now, he said, scientists can make a more complete map of raptors biological and geographical history - where they lived, how old the various species lineages were, and how long ago they diversified from each other.
The scientists named the raptor based on the Patagonian province where it was found, Neuquén.
Counting Neuquenraptor, the raptor family tree now has eleven official branches, including Velociraptor, Utahraptor, and pint-sized Microraptor. All share a common ancestor with modern birds.
The National Geographic Society and the Agencia de Promocion Cientifica in Argentina funded Novas research and the fieldwork for the study. Pols analysis of the fossils was funded by Ohio State.
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Global Warming Led To Atmospheric Hydrogen Sulfide And Permian Extinction
University Park PA (SPX) Feb 23, 2005
Volcanic eruptions in Siberia 251 million years ago may have started a cascade of events leading to high hydrogen sulfide levels in the oceans and atmosphere and precipitating the largest mass extinction in Earth's history, according to a Penn State geoscientist.