Y’know, I think I’ve d/led this before, and wow, 40 page PDF, I plan to wimp out for now and see if there’s a wiki-wacky-pedia page about it. ;’)
http://news.nationalgeographic.com/news/2009/10/091016-asteroid-impact-india-dinosaurs.html
Others not convinced, but that could be the murmur from [as Sheldon Cooper would say] the rock people; multiple impact event is just fine with me.
http://en.wikipedia.org/wiki/Shiva_crater
The full article at the top has a lot of interesting links related to extinction events. I agree there were probable multiple causes of the extinction event(s). Around 34 mya there were at least 3 boloids that caused a smaller extinction result. One was the 60 mile diameter Chesapeake Meteor strike, another the similar size Popogai(sp?) Meteor strike in Russia, and also the 9 mile diameter Toms River crater off the New Jersey coast. Many remember the impressive Shoemaker/Levy train of meteors striking Jupiter.
Another subject of interest for us volcano aficionados is the Toba volcano which left an 18 by 65 mile crater on Sumatra around 74,000 ya. Here is an article with several links on that topic.
http://www.sciencedaily.com/articles/t/toba_catastrophe_theory.htm