One theory is that they drowned in the Great Flood, the one avoided by Noah and seven of his family members, along with a boatload (get it?) of birds and animals hand-picked in seven pairs of twos to repopulate the world.
Maybe the dinosaurs were too big to be included. Maybe there were just too many of them.
For an expansion on a literalist/creationist take on things, go here. I was trained to answer people who talked about carbon dating with a “Maybe God made the rocks look older than they actually are.”
And thanks, Tim, for the link.
Dating Jesus 
Dinosaurs are stanky. Much too stanky to live in close quarters with civilized god-fearing animals. That’s why they got left behind.
Same thing’s gonna happen to Leftists and such. I saw it in a movie.
You’ve been warned.
Is it like a matter of degrees? Because I’m pretty far left. Today, I was told I was edgy. I floated in a cloud back to my car.
It’s a with-us/agin-us thing. The finale will be a surprise. God likes surprises, apparently.
That’s what happens in the movie. POOF! Find another ride to the Walmart.
Find another ride to the Walmart, rather than on the local dinosaur?
I didn’t see any dinosaurs in the movie.
Dammit.
I’m very glad you posted this. I feel so much more informed. And, I can’t get “Puff, the Magic Dragon” out of my head.
Ha. You’re welcome.