@CrimsonCloud Facepalm - just like humans are basically a genetic deformation of apes, chickens must be a genetic deformation (or evolutionary stage) of protochickens. So the egg was laid, yet it was a protochicken egg, but because they were evolving into what we call a chicken today, it turned into a prereleasechicken, which then laid an egg, which evolved to be a chicken egg.
I'm just tweaking my whole evolutionary theory of chickens... Very-early-protochicken-egg -> Protochicken lays protochicken egg, which hatches into -> Alphachicken lays alphachicken egg, which hatches into -> Betachicken lays betachicken egg, which hatches into -> Prereleasechicken lays prereleasechicken egg, which hatches into -> Chicken!