Tuesday, April 28, 2009

Way Off Topic: The Extinction of the Dinosaurs

An asteroid didn’t kill the dinosaurs? Say it ain’t so! A recent article from The Journal of the Geological Society (Time reports on it here) claims that perhaps an asteroid wasn’t the cause of the mass extinction of dinosaurs 65 million years ago.

For those less familiar with the death of the “terrible lizards,” the common theory goes like this: 65 million years ago an asteroid hit the Yucatán peninsula resulting in a massive dust cloud that cooled Earth, thus killing the cold-blooded dinosaurs. There’s lots of proof for this theory, including a telltale 65-million-year-old, 112-mile crater on the Yucatán peninsula. There’s also a layer of iridium in the sediment layer at the 65-million-year depth; iridium is rare on Earth but common in asteroids.

Geoscientists Gerta Keller and Thierry Addate—don’t laugh, they’re Swiss—did some digging around the Yucatán and discovered that just below and above the layer of iridium were the same 52 fossilized species. These findings would indicate that there wasn’t an immediate, massive extinction caused by the asteroid. It was only after they looked at sediment 30 feet above that they found species disappear. According to Keller and Addate, that 30-foot layer of sediment would have taken 300,000 years to accumulate.

The research by Keller and Addate is controversial because it contradicts the findings of other digs from around the world. According to the article, theirs is the first survey that looks at the sediment record so close to the impact site. They claim that their research is more accurate because it was close to the impact, but, of course, other paleontologists say that its proximity makes it less accurate. Wait, the experts disagree? Shocking.

So what does this mean for amateur dino-nerds like me? Unfortunately, not much. Until there is further disproof of the asteroid extinction theory, it seems to make the most sense. Although I think Gary Larson figured it out a while back:

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