A cladistic analysis of the genera in the subfamily Pudicinae (Nematoda, Trichostrongyloidea, Heligmonellidae).

A parsimony analysis was performed on 37 specific taxa belonging to the subfamily Pudicinae (family Heligmonellidae), which contains parasites mainly from South American caviomorph rodents. Thirteen characters were used from the synlophe (rotation of axis, presence of carene, carene asymmetry, presence of comaretes, single ventral comarete length, ridge discontinuity, ventral ridge numbers, presence of a peculiar posterior synlophe, presence of supernumerary spines) and the male caudal bursa (relative length of rays 9 and 10, caudal bursa type, division of the dorsal ray, divergence of the 10th rays). The cladogram shows a consistency index of 1.0. The subfamily Pudicinae has two synapomorphies. Two suprageneric groups are recognized. Suprageneric group 1 shows one synapomorphy and contains Heligmostrongylus, Fuellebornema, Sciurodendrium and Pseudoheligmosomum; suprageneric group 2 shows two synapomorphies and contains Pudica, Acanthostrongylus, Justinema and Durettestrongylus. Five genera are defined on the basis of synapomorphies. The genera Heligmostrongylus, Sciurodendrium and Pudica which are considered paraphyletic, however, are retained due to lack of knowledge as to their relationships.