“The thing we call a “chicken” never developed as a mating pair, but hatched out as a combination of genes from its parents and ancestry.”
So the chicken was a mutant of some previous animal that laid eggs.
And so which came first the chickens progenitor or its eggs?
I’ll type slowly this time for you: the thing we call “chicken” came about from a mix of genes from parents which weren’t exactly what we call a “chicken,” and yes, this kind of “evolution” does happen in real life, but too slow for humans to follow or make the connections.
Just as modern wolves, horses, and many other mammals have NO representation in the paleological records past a few tens of thousands or hundreds of thousands of years, but similar animals do.
What came FIRST was the egg, containing the completed - or close enough for chinese food - chicken.