Papua New Guinea notable feature in common for the two landmasses is the existence of several species of marsupial mammals, including some kangaroos and possums, which are not found elsewhere. Papua New Guinea is a megadiverse country. Many of the other islands within PNG territory, including New Britain, New Ireland, Bougainville, the Admiralty Islands, the Trobriand Islands, and the Louisiade Archipelago, were never linked to New Guinea by land bridges. As a consequence, they have their own flora and fauna; in particular, they lack many of the land mammals and flightless birds that are common to New Guinea and Australia. Australia and New
Fauna of New Guinea has reached Australia. "Nyctimystes" are arboreal frogs, which lay their eggs in fast flowing streams, behind a rock to avoid it being flushed away. The tadpoles have modified mouths, which use suction to stick to rocks. Ranidae, also known as true frogs, are the most widely distributed family of frogs on earth, however, they are not well represented in Australia or New Guinea. New Guinea and Australia have been absent of Ranids for most of their history, however since the continent's collision with Asia, species have begun to move across. The Ranids in New Guinea are only represented with one