You know the riddle, "What came first, the chicken or the egg?" I have solved it! If you're a smart-ass, you'd probably say "chicken" because it came first in the sentence. But push that smart-assery aside and focus on which of the two existed before the other in history to solve the riddle, and you'd find that the EGG came first. The riddle never said that it had to be a CHICKEN egg. Dinosaurs came first and they hatched from eggs long before their feathered, warm-blooded cousins came along. I haz a smart.
Now I can sleep tonight.

Fish existed before Dinosaurs and they hatched from eggs, too.
So your deduction is correct, but worded wrong.