Where, apart from Australia, are monotremes found?
Australia (continent) to the Australian mainland. As the continent drifted north from Antarctica, a unique fauna, flora and mycobiota developed. Marsupials and monotremes also existed on other continents, but only in Australia–New Guinea did they out-compete the placental mammals and come to dominate. New Guinea has 284 species and six orders of mammals: monotremes, three orders of marsupials, rodents and bats; 195 of the mammal species (69%) are endemic. New Guinea has a rich diversity of coral life and 1,200 species of fish have been found. Also about 600 species of reef-building coral—the latter equal to 75 percent of the world’s known
Natural history of Australia the world’s three major groups of extant mammals had their origin in the Australian part of the Gondwana supercontinent, the monotremes and marsupials. The oldest mammal fossils from Australia are monotreme fossils from the Cretaceous of Southern Australia. These lived at a time when Australia was part of a small Gondwana (also including Antarctica and New Zealand) which was beginning to drift apart. They are based on isolated jaws and postcranial bones from Lightning Ridge, New South Wales and southern Victoria sites (near Inverloch), dated at between 120 and 110 Ma. Several taxa (Teinolophos, Bishops) existed alongside primitive tribosphenic mammals