The egg or the chicken???
Well, in my (strange) family, the answer has been passed down:
As the dinosaurs roamed the earth, if the chicken was created, it wouldn't last 5 seconds, but one dino was a releventely close to the chicken.... a good few years later, the dino's where extinct but one dinosour, not known, left one egg. it hatched 7 years later. At that time, there was nothing on the planet except for that one egg, which hatched in to a cross between a dino and a chicken (and a duck but it didn't make much difference) so, it would lay eggs but be dangerous. But much later, something happened, the dino part died, no one knows how, it just did, leaving the chicken. so the answer is the egg, as it hatched the chicken....