Why Are Dinosaurs Extinct?

Xander asked today at lunch, "Why are dinosaur's extinct?"  

I answered, "No one really knows why.  Some say it got too hot.  Some think they ran out of food." 

Chris answered, "Some people think they got stuck."

Xander thought about our answers.  Then he informed us that, "No, that's not why."

"Why," both Chris and I asked at the same time.

"Because," he began, "they crawled into duck eggs and had no feet.  That's why they are extinct."

Ok, good to know!