RESUMO
Pterygodermatites (Paucipectines) zygodontomis, a nematode parasite of the small intestine of the rodent Necromys lasiurus, from Uberlândia, Minas Gerais state, Brazil, was analysed by light and scanning electron microscopy. Additionally, phylogenies were inferred from the mitochondrially encoded cytochrome c oxidase I gene (MT-CO1). Details of the helminth surface, such as the oral aperture, cephalic papillae, papillae in the posterior region of the body and longitudinal cuticular elements represented by spine-like projections and fans are presented, adding new taxonomic details. Molecular phylogenetic analysis, based on the MT-CO1, demonstrated that P. (P.) zygodontomis and Pterygodermatites (Paucipectines) jaegerskioldi form a unique evolutionary unit in accordance with the subgenus Paucipectines and corroborated their occurrence in cricetid and didelphid hosts.