There are also some theories that it was not one meteorite impact (the one in Yucatan) that did the dinosaurs, but several in fact. There is a crater in Ukraine (Boltysh) which is around 65 million years old, plus some suspect that there might be ones in the North Sea and off the coast of India from around that period as well. I suspect it was a combination of Deccan Traps thinning the herds first, and then these impacts killing them off for good.