michaelgreshko

Joined 9 years ago

Karma
204
Submissions
4
Member since
May 12
I'm a science journalist at National Geographic.
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Comment · 9 years ago
Personally, I've not seen any evidence that ankylosaurs (including nodosaurs) had feathers. But who knows?
Comment · 9 years ago
What zbyte64 said. Once the animal dies, the enzymes that constantly fix and error-check DNA are no longer around. DNA then degrades over time, cleaving in half every ~521 years on average. So past a million years or two, the fragments are so small, meaningfully putting them back together would be an impossible task, like reconstructing a porcelain bowl you had ground into dust.
Comment · 9 years ago
Comment · 9 years ago
Hey, I'm the journalist who wrote the story. A few things: - The organic-rich film preserving the outlines of scales (so, yes, fossilized skin) is only a few millimeters thick. So Mitchell had to prepare the fossil extremely slowly in order to follow the film through the matrix. - The half-life of DNA is ~521 years at 13.1°C, as found in this 2012 paper: http://rspb.royalsocietypublishing.org/content/279/1748/4724 The team's model predicts higher half-lifes at truly freezing temperatures, but even at the extreme end, there's no way DNA would survive 110 million years. - The dating on the site is well constrained to ~110 million years old. The fossil was found in the Wabiskaw Member of the Clearwater Formation, a well-dated rock formation in Alberta. The underlying oil sands have been radiometrically dated to 112±5.3 million years old. (http://science.sciencemag.org/content/308/5726/1293)

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