The butt was there first.
For an egg to came into existence that would later evolve into that chicken, first there has to be a butt that this egg came out.
However since we lack the means to verify and measure this butt, its being generally accepted that the egg was there first, despite the factual evidence that it couldnt have been there suddenly and simply like that, which in turn raises extravagant questions about the origins of the species of our everyday chicken.
Hereby worthy to note if the butt could even get proven, then we would have been encountered yet another eggregious question: Then which species butt is that again ?