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
Papua New Guinea largest towns are also located, including Port Moresby (capital) and Lae; other major islands within Papua New Guinea include New Ireland, New Britain, Manus and Bougainville. Papua New Guinea is one of the few regions close to the equator that experience snowfall, which occurs in the most elevated parts of the mainland. The border between Papua New Guinea and Indonesia was confirmed by treaty with Australia before independence in 1974. Maritime boundaries with Australia were confirmed by a treaty in 1978. Papua New Guinea is part of the Australasia ecozone, which also includes Australia, New Zealand, eastern Indonesia, and several