Polystomatidae is a monogenean family whose representatives infect mainly (semi)-aquatic tetrapods. Species ofSphyranuraWright, 1879 exhibit ectoparasitism on salamander hosts, with molecular work supporting their inclusion within Polystomatidae, at an early diverging, yet unresolved, position in the clade of otherwise endoparasitic polystomatid parasites of batrachian hosts. Records of representatives ofSphyranuraare scarce with genetic data only available forS. oligorchisAlvey, 1933. Based on detailed morphological examination and comparison with type material, we identified worms belonging toSphyranurainfecting Oklahoma salamander (Eurycea tynerensis) asS. euryceaeHughes & Moore, 1943. Along with an amended diagnosis ofSphyranura, we provide the first molecular data forS. euryceaein the form of a mitochondrial genome and nuclear (18S,28SrRNA) markers. Close morphological similarity between the two species ofSphyranurais reflected in low genetic divergence. Mitochondrial level comparison reveals instances of tRNA gene rearrangements in polystomatids. Although the phylogenetic reconstruction supportsSphyranuraas early branching in the lineage of polystomatid monogeneans infecting batrachians, certain nodes remain unresolved.