Are platypus related to seals or otters?

Platypuses are not closely related to seals or otters. While they share some similarities in their aquatic lifestyle, they are actually more closely related to echidnas (spiny anteaters).

Here's a breakdown:

* Platypuses and echidnas are both monotremes. Monotremes are a group of mammals that lay eggs, unlike most mammals that give birth to live young. They are the only surviving members of this ancient lineage.

* Seals and otters are mammals, but they are placental mammals. Placental mammals develop their young inside the mother's body, connected by a placenta.

While the platypus's duck-like bill and otter-like body shape might lead you to think they are related, their evolutionary history points to a different conclusion.