Imagine a saber-toothed predator—but instead of being a big cat, it’s a marsupial. Thylacosmilus was a bizarre prehistoric mammal with huge fangs, yet it carried its young in a pouch.

Related: Ancient marsupial sabertooth had eyes like no other mammal predator Placental mammals have a range of developmental strategies. For example, human babies are practically helpless at birth ...

The marsupial frog, which incubates its young in a pouch on its back, was thought to be extinct in some countries By Danna Staaf The horned marsupial frog, which carries its eggs in a pouch on its ...