Monotremes

The monotremes are those very unique mammals that lay soft shelled eggs in which the young partially develop; but when hatched the young are then suckled on milk. This sub-class of mammal only has five extant species, the platypus and four species of echidna. Three of the echidna species are endemic to New Guinea and the fourth is found in both New Guinea and in all states of Australia. Therefore Australia has two monotremes, the short-beaked echidna and the platypus.