Then I asked online, and an acquaintance said "Yes, meteor. (Too soon?)"
And then I imagined: all that dust. Dust (from an explosion that leveled at least 9,500 square miles) filling the skies...and deep dinosaur sinuses for it to get into. Tyrannosaurus Rexes sneezing epic sneezes. Diplodocuses knocking their heads (on their long, long necks) painfully against trees or the ground. SUCH AN UNDIGNIFIED WAY TO GO.
That's it. The dinosaurs died of embarrassment.
The mammals, of course, survived, but were too focused on surviving the cold to do the earliest ever Nelson Muntz "Ha-ha!" But I kind of want to imagine that they still did.
(...getting science wrong is fun.)