I looked at that question as to what came first, the chicken or the egg, and here is one answer from BBC Science Forum, see what you think:
"Eggs are much older than chickens.
Dinosaurs laid eggs, the fish that first crawled out of the sea laid eggs, and the weird articulated monsters that swam in the warm shallow seas of the Cambrian Period 500 million years ago also laid eggs. They weren’t chicken’s eggs, but they were still eggs...".
(The rest is in link, it's not long...)
https://www.sciencefocus.com/nature/which-came-first-the-chicken-or-the-egg
Now again, if I were in a class and the teacher said this, I'd wonder a few things while scratching my head: how do scientists KNOW that the fish that first crawled out of the sea laid eggs? I'll start there...and frankly, I doubt I would get a valid response with actual literal evidence. Of course there were no x-rays like we have today of embryonic development within a womb.