Syphacia (Syphacia) Australasiensis sp.nov. (Nematoda: Oxyuridae) from Rattus Leucopus (Muridae) from Papua New Guinea and Australia

Syphacia (Syphacia) australasiensis sp. nov. is described from the caecum of Rattus leucopus (Gray) (Rodentia: Muridae) from Papua New Guinea and Queensland, Australia. The new species is distinguished from congeners with an oval cephalic plateau by the lack of lateral alae, a longitudinal ridge along the egg and a combination of measurements including spicule length, tail length, distance to anterior mamelon and size of eggs. The origins of the genus and the relationships of the species in the Australian region are discussed.