Beutelsäuger

Beuteltiere, also known as marsupials, are a infraclass of mammals that are found primarily in Australasia and the Americas. They are distinguished by giving birth to relatively undeveloped young, which then complete their development in a pouch. This pouch, or marsupium, is a characteristic feature of most female marsupials, although it is absent in some species. The young, called joeys, are tiny and embryonic at birth, typically weighing less than a gram. After birth, the joey crawls to the mother's pouch and attaches itself to a teat, where it will continue to grow and mature for several weeks or months, depending on the species.

The diversity of marsupials is remarkable, ranging from the iconic kangaroo and koala of Australia to the opossums of the Americas. They occupy a wide array of ecological niches, including herbivores, carnivores, and omnivores. Their evolutionary history is distinct from that of placental mammals, with which they share a common mammalian ancestor. Marsupials represent an ancient lineage that has diversified significantly in isolated environments.