Phylogenetic relationships among the species of Pyelosomum Looss, 1899 (Digenea: Pronocephalidae).

Comparative morphological study of 10 nominal species of pronocephalids 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 Myosaccus chelonei species incertae sedis. Phylogenetic analysis of the 7 recognized species, based on 18 morphological transformation series, produced a single tree with a consistency index of 86%. That tree suggests that Pyelosomum is paraphyletic unless Astrorchis, Epibathra, and Myosaccus are included in it. Accordingly, all are considered junior synonyms of Pyelosomum. Epibathra stenobursata is designated Pyelosomum stenobursata comb. n.