Question: is a platypus a marsupial?
Answer: Originally Answered: Why is the platypus a marsupial? They are not Marsupials, they are Monotremes; Mammals that lay eggs. To be a marsupial, in part you have to give birth to underdeveloped offspring, that then spend a part of their development nursing from a pouch on the mother's stomach, Platypi don't do this.