Marsupials are distinguished from other mammals by their unique reproductive process, which typically involves giving birth to relatively undeveloped young that continue to develop further in a pouch on the mother's belly, known as a marsupium. This characteristic is most famously seen in kangaroos, koalas, and opossums. The pouch provides a safe environment for the young to grow and nurse. Marsupials differ from placental mammals, which develop their young to a more advanced stage before birth. This reproductive strategy is particularly well-suited to the diverse environments and survival needs of marsupials in Australia and surrounding areas.