What came before the chicken or the egg?

Earlier, an egg appeared, that is, an organic cell.
And also on the globe, the egg also appeared first.
An egg or oocyte is an egg cell from which the development of the embryo outside the uterus occurs.
Then I will develop my thought and dream up …
It is likely that the egg was originally soft, but due to some need it became overgrown with a hard shell. Or maybe on the contrary, the shell of the egg – the cell was stone or even iron like a meteorite.
An egg is a kind of capsule with a supply of nutrients, and if the egg is fertilized, then someone will hatch from it, and as you know, the environment has a direct impact on who hatches and what will develop. In general, something had to happen that influenced the development of the embryo and he became, for example, not a dinosaur or something else, but a chicken.