Mammals: Mammalia

Mammals are divided into three groups - monotremes, marsupials and placentals, all of which have fur, produce milk and are warm-blooded.

The Platypus and echidnas are monotremes and the females lay soft-shelled eggs. Marsupials give birth to small, poorly developed young and most female marsupials, such as kangaroos, wallabies and the Koala, have pouches. Placental mammals, like humans, rodents and bats, differ from monotremes and marsupials in that they generally give birth to well-developed young.

Mammals are a diverse group, but all mammals

  • produce milk to feed their young
  • have hair or fur
  • have a unique jaw structure
  • are warm-blooded.

Mammals in Sydney

Sydney is home to a range of mammal species, both native and introduced. Some species have adapted extremely well to sharing their environment with the most abundant mammal in Sydney - humans. Others have not fared so well and, since European settlement, 60% of the original number of mammals is now considered endangered or vulnerable.

Mammal finders

Use the following finders to locate the information our website has on particular mammal species and groups:


Dr Sandy Ingleby , Collection Manager, Mammalogy
Last Updated:

Tags mammals, eutherians, marsupials, prototherians, placentals, monotremes, vertebrates,