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PALEONEWS: more on dinosaur heart study



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This is a CNN custom news article.
CNN has recently changed formats so I can not give you the URL.
I recommend registering at cnn.com for your own custom news
to access the article online-   -Betty
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New Study Shows Dinosaur Warmblooded

WASHINGTON (April 25) XINHUA - A new study on a fossilized dinosaur
heart has led to an important discovery that extinct dinosaurs were
warmblooded animals, instead of coldblooded ones. 

The first-ever fossilized dinosaur heart seems to have four chambers
which indicate that dinosaurs were warmblooded animals, like birds and
mammals, scientists from the North Carolina State University wrote in
the latest issue of journal Science. 

The dinosaur, called Thescelosaurus living 66 million years ago, was
unearthed in 1993 by professional fossil hunter Michael Hammer, working
with his son in South Dakota's Hell Creek, where they had found
dinosaurs earlier in the year. 

As he began emptying the chest cavity, Hammer saw a concretion and
suspected it was the heart because of the placement. Then, a team of
researchers from North Carolina State University began the heart
investigation, which led to the discovery of the four- chambered heart. 

Team member Dale Russell, a paleontologist explained that the key
finding was not the heart but the single aorta. 

"This means that low- and high-oxygen blood were separated," Russell
said, a signal that Thescelosaurus had much higher metabolism than
cold-blooded reptiles, which have two aortas and mixed low- and
high-oxygen blood. 

"A higher metabolic rate means a higher activity level," Russell said, a
trait commonly noted among warm-blooded animals like birds and mammals. 

Although the findings support the view that dinosaurs were warm-
blooded, Russell noted that research up to now has focused on raptors
and other small carnivores that display the strongest evidence of a
bird-dinosaur link. 

-- 
Flying Goat Graphics
http://www.flyinggoat.com
(Society of Vertebrate Paleontology member)
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