Definite: Asteroid got dinosaurs (Introduction)
Chicxulub redated: more than likely dino extinction due to it. Date4s are very close.-http://www.sciencedaily.com/releases/2013/02/130207141444.htm
Definite: Asteroid got dinosaurs
More on chicxulub:-http://online.wsj.com/article/SB10001424127887324880504578298022042998786.html?KEYWORDS=Matt+Ridley-Very complete discussion