Chicxulub Crater Satellite Image by NASA
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Here's how the story has been told for decades...
About 65 million years ago a large asteroid or comet impacted the northwest coastline of the Yucatan Peninsula, Mexico. This impact left a crater about 112 miles wide and ejecta from the impact was carried high into the atmosphere and spread around the Earth. This temporarily reduced the amount of incoming solar radiation received by Earth. The interruption in solar radiation was long enough for the food chain to collapse and accounted for one of the greatest extinctions in Earth's history. Many scientists believe that over 70 percent of Earth's species were pushed into extinction - including the dinosaurs.
Now, Princeton University paleontologist Gerta Keller, Thierry Adatte from the University of Neuchatel, Switzerland, along with Zsolt Berner and Doris Stueben from Karlsruhe University in Germany say that the Chicxulub impact event was just one of a series of events that stressed Earth's systems and led to one of the greatest mass extinctions in the history of our planet. These researchers believe that Chicxulub predates the extinction and that a much larger, and still unidentified, impact dealt the most important blow. Here's how they think this happened....
"Chicxulub, though violent, actually conspired with the prolonged and gigantic volcanic eruptions of the Deccan Flood Basalts in India, as well as with climate change, to nudge species towards the brink. They were then pushed over with a second large meteor impact."
Their research was funded by the National Science Foundation and more details can be found at the
NSF Website.
Labels: Dinosaurs, Meteor-Meteorite
The Three Faces of Dinosaurs is a new WebExtra by Spencer G. Lucas (curator of paleontology and geology at the New Mexico Museum of Natural History) posted at the GEOTIMES website. This article describes how paleontologists' perceptions of dinosaurs have changed during the past 200 years. These perceptions have ranged from dinosaurs being directly linked to lizards, then reptiles, then birds and ending with current ideas.
Read more at
The Three Faces of Dinosaurs.
Labels: Dinosaurs, Fossils
