How did those pesky dinosaurs go extinct? Until recently I believed the general consensus was that a big old asteroid smashed into the Yuccantan peninsula in Mexico decimating these "terrible lizards" once and for all. After listening to a recent interview with Donald Prothero on Skepticality it's come to my realization that the answer isn't so simple.
Seperating the Mezoic era from the Cenzoic era is geological signature called the K-T boundary. Basically it marks the end of the age of dinosaurs and the beginning of the mammalian take over. It was my long held belief that the Chixculub crater (created by the aforementioned meteor) was generally believed to be the sole creator the K-T boundary, and thus the massive dinosaur extinction.
In his recent interview Dr. Prothero did not say this impact did not happen, nor that it did not have a significant role to play in the K-T extinction, but that it alone could not have possibly done the job of finishing off the dinosaurs. Instead Prothero suggested that it was a combination of events stretched over a longer period of time that lead to the gradual decline of the dinosaurs. Surprisingly this isn't really new information. Paleontologists have known the extinction of the dinosaurs to have been a more gradual event for quite some time, in fact, Prothero goes as far to say most paleontologists never bought into the idea that an asteroid hypothesis was solely responsible.
This is because the fossils they spend their life working with tell quite a different story. Some dinosaurs lived past the asteroid impact event, not to mention a plethora of other life forms, from which all living things can trace their ancestry. There were other events which played significant roles in the K-T extinction. A giant volcanic eruption in India being one of them.
Recently the asteroid extinction hypothesis has been under great scrutiny as demonstrated by this article "Dino killing" asteroid theory takes fresh hit. I guess it's a wise idea to listen to what those crazy paleontologists have to say a little more often.