The egg.
Another of life’s great mysteries solved 
And where did the egg come from, Tap? Did it just drop out of the sky?!
The correct answer is the chicken, since it was born with modifications that allowed for the laying of eggs.
But reptiles were laying eggs before they turned into birds…so I guess the correct answer is the lizard came first, then the egg then the ch…
:smack:
Never mind.
Myself
Cecil answered this over 20 years ago: http://www.straightdope.com/classics/a2_218.html
And how on earth did it take an entire “team” of scientists and researchers to come up with such an obvious answer? Sheesh. What a weird non-story.
Well, I was in the barn the other day and I pulled down a bale of hay. An egg glanced off my forehead and landed in a pile of hay on the floor. It didn’t even crack, which suprised me almost as much as the fact than a egg came flying at me. Seconds later a very disgruntled chicken came flapping down at me.
So I offer that up as support that the egg came first.
My thoughts exactly.
“If a kangaroo laid an egg from which an ostrich hatched, that would surely be an ostrich egg, not a kangaroo egg.”
And one sore kangaroo I’m thinking.