Board Thread:Questions and Answers/@comment-27598407-20160206111656/@comment-27598407-20160209124129

" Even birds have belly buttons, they are just less pronounced than in mammals. The developing foetus still needs a link to the yolk sac within the eggs. So even egg laying monsters will have bell buttons."

I didn't know about that, I though it was only mammals who have that.

Thank you everyone for your answers !