Yeah, I know it sounds silly but did you ever think of that, what comes first, the egg or the chicken? I have two answers in mind but I'm curious to hear your opinions. The most imaginary idea takes as a prize...um...how about the solutions to my quizzes?
Just kidding

An unscientific thought, but I reckon that it was a hybrid between two other birds that heretofore hadn't mated (the Romeo and Juliet of the bird world, perhaps) and voila you get an egg. Maybe, you just never know!

hm... quite interesting my dear (pushing my glasses closer to my eyes and looking serious) You mean that the egg came from two different birds and that's why became an egg and not a baby bird? Do you mean that maybe until then birds gave birth to tiny birds? Well, it comes close to the one answer of mine, but it's not quite the same, though it's very interesting, dear...