A new genus of hemibelideine possum (Marsupialia: Pseudocheiridae) from New Guinea and Australia, including a Lazarus taxon from the Vogelkop Peninsula
Abstract
A new genus of gliding marsupial (Hemibelideinae; Pseudocheiridae) is proposed for several possums previously known only as fossils: ‘Petauroides’ ayamaruensis Aplin, 1999 (Quaternary of the Vogelkop Peninsula of western New Guinea), Pseudocheirus stirtoni Turnbull and Lundelius, 1970 (Pliocene of Victoria and New South Wales), and an unallocated species from the Middle Pleistocene of Queensland. The type species (ayamaruensis) is based on early Holocene archaeological material from the Vogelkop, mainly lower jaws and teeth, and was presumed to have been extinct for around 6,000 years. However, here we describe living individuals of ayamaruensis, thus a ‘Lazarus species’ (‘rediscovered’ after considered to be extinct), from several locations in the West Papuan region, as well as abundant archaeological material from ca. 1,000 km to the east in Sandaun Province, Papua New Guinea. The Sandaun material provides the first upper dentition known for this species. ‘Petauroides’ ayamaruensis is restricted to the Vogelkop and North Coast Ranges, and is the only hemibelideine known from New Guinea. Observations of modern animals representing ayamaruensis help to cement its status as an extremely distinctive marsupial, and access to its full dentition clarifies its relationship to fossil and living Australian possums. This newly described genus is present in the Australian Pliocene and Pleistocene fossil record, and its living relatives are the Greater gliders (Petauroides spp.) and the Lemuroid ringtail (Hemibelideus lemuroides) of eastern Australia. Traditional landowners from Maybrat Regency in the Vogelkop are familiar with ayamaruensis and relate that it roosts in tree hollows in the tallest and most commercially valuable timber trees of the lowland rainforest, and that a pair produces only a single young per year. It may also still survive in the Mamberamo Basin of western New Guinea and the Torricelli Mountains of Papua New Guinea. It is gravely threatened by logging and forest conversion, both of which continue to expand in West Papua and Papua New Guinea.
