PHYLOGENETIC-RELATIONSHIPS AMONG THE SPECIES OF PYELOSOMUM LOOSS, 1899 (DIGENEA, PRONOCEPHALIDAE)

Comparative morphological study of 10 nominal species of pronocephalid s forming a clade diagnosed by plump rounded bodies, sinuous ceca, and short esophagi supports the recognition of 7 species, with Pyelosomum longicaecum a junior synonym of P. renicapite, and P. solum and Myosa ccus chelonei species incertae sedis. Phylogenetic analysis of the 7 r ecognized species, based on 18 morphological transformation series, pr oduced a single tree with a consistency index of 86%. That tree sugges ts that Pyelosomum is paraphyletic unless Astrorchis, Epibathra, and M yosaccus are included in it. Accordingly, all are considered junior sy nonyms of Pyelosomum. Epibathra stenobursata is designated Pyelosomum stenobursata comb. n.