Posted on 01/24/2011 2:55:25 PM PST by decimon
Careful dating of new dinosaur fossils and volcanic ash around them by researchers from UC Davis and UC Berkeley casts doubt on the idea that dinosaurs appeared and opportunistically replaced other animals. Instead -- at least in one South American valley -- they seem to have existed side by side and gone through similar periods of extinction.
Geologists from Argentina and the United States announced earlier this month the discovery of a new dinosaur that roamed what is now South America 230 million years ago, at the beginning of the age of the dinosaurs. The newly discovered Eodramaeus, or "dawn runner," was a predatory dinosaur that walked (or ran) on two legs and weighed 10 to 15 pounds. The new fossil was described in a paper by Ricardo Martinez of the Universidad Nacional de San Juan, Argentina, and colleagues in the journal Science Jan. 14.
The fossils come from a valley in the foothills of the Andes in northwestern Argentina. More than 200 million years ago, it was a rift valley on the western edge of the supercontinent Pangaea, surrounded by volcanoes. It's one of the few places in the world where a piece of tectonically active continental margin has been preserved, said Isabel Montañez, a UC Davis geology professor and a co-author of the Science paper.
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According to Montañez, there are two major temporal boundaries in the geology of the era: The Carnian-Norian boundary at 228 million years ago and the Triassic-Jurassic transition at about 210 million years ago. Geologists have long thought that dinosaurs jumped in number and variety at both points, opportunistically replacing other reptiles.
(Excerpt) Read more at news.ucdavis.edu ...
Dating dinosaurs ping.
Pics of Helen Thomas in 3.2.1...
Meet your perfect match at DINODate!!
Sorry no Allisaurus’ at this time.
Is a Cougar a dinosaur?
Izzis ‘bout that SOTU Stuff?
At first I thought this thread was about my social life.
I once dated a fossil.
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Thanks for the yawn.
Now I can’t stop.
I’m gonna half to go lie down.
It’s the yawn of a new day, Civ.
Perhaps. If one is dating an anthropologist who likes to talk shop.
I lava your word play.
I wound up going to bed before 10 last night, I was fallin’ asleep here.
The dinosaurs hunted the hot babes in bikinis to extinction. They would not reappear for a million years.
Looks like a Goldfinger outtake. :’)
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