Emended description of Mazamastrongylus peruvianus (Nematoda:Trichostrongylidae), with comments on the relationships of the genera Mazamastrongylus and Spiculopteragia.

Resurrection of Mazamastrongylus as proposed by Jansen (1986) was validated and placement of Mazamastrongylus peruvianus in this genus was confirmed, based on characters of the synlophe, copulatory bursa, and spicules. The cervical synlophe consists of a strongly tapering pattern and prominent "hood ridges" at the level of the excretory pore; there are 40 ridges at the midbody of males. The bursa is of the 2-2-1 type, with rays 2 and 3 parallel and rays 4 and 5 of near equal length and only slightly divergent at the tips. The spoon-shaped dorsal process of the spicules, typical of M. peruvianus and other species of Mazamastrongylus is postulated as a synapomorphy for the genus. The genera Mazamastrongylus, Spiculopteragia, and Sarwaria are considered to be independent based on characters of the synlophe, spicules, and copulatory bursa. Host and geographic distributions for species of Mazamastrongylus appear to be consistent with a history of coevolution and colonization and relationships for M. peruvianus may parallel the pattern postulated for species of Nematodirus in cervids and camelids in the Neotropics.