A new species of Oesophagostomoides (Nematoda: Cloacinidae) from the northern hairy-nosed wombat Lasiorhinus krefftii with a key to species of the genus.

Lasiorhinus krefftii, the northern hairy-nosed wombat, is a rare and endangered marsupial existing as a single population in the Epping Forest National Park, Queensland, Australia. Dissection of a juvenile wombat that had died from natural causes revealed the presence in the colon of a new species of Oesophagostomoides Schwartz, 1928, a genus found only in wombats (Vombatidae, Marsupialia). Oesophagostomoides eppingensis n. sp. differs from the other species in the genus in the length of spicule, form of the dorsal ray, length of the vagina, and proportions of the female's posterior end. Morphological similarities between species suggest that there may have been switching of the species of Oesophagostomoides between L. krefftii and Vombatus ursinus (the common wombat). The potential contribution of colon parasites to the energy budget of wombats may be of importance when determining conservation management strategies for L. krefftii.