EN
Cosmocerca tyleri sp. nov. (Ascaridida, Cosmocercidae) from the large intestine of Genyophryne thomsoni (Anura, Microhylidae) is described and illustrated. Cosmocerca tyleri sp. nov. represents the 23rd species assigned to the genus and the 6th from the Australian realm. Of the 5 Australian species previously described, C. tyleri sp. nov. differs from C. limnodynastes and C. novaeguineae in number of plectanes, 4 pairs in C. tyleri, 5 pairs in C. limnodynastes and C. novaeguineae. Cosmocerca australis has 3–4 pairs of plectanes, C. archeyi and C. zugi each have 4 pairs of plectanes; however, in each species the plectanes lie in the fourth quarter of the body and just anterior to the cloaca. In C. tyleri sp. nov. the plectanes lie in the third quarter of the body and there is significant space between the cloaca and the posterior pair of plectanes.