Redescription and phylogenetic relationships of the rare Lyperosomum sarothrurae Baer, 1959 (Digenea: Dicrocoeliidae).

Lyperosomum sarothrurae Baer, 1959 is a rare dicrocoeliid described based on a single specimen from Belgian Congo, now Democratic Republic of the Congo, and never reported again. The original description lacked several important details of the species morphology. This work provides morphological redescription of Lyp. sarothrurae based on specimens from Kibale National Park, Uganda which is about 200 kilometres from the type locality. Results of re-examination of the holotype are also provided. Morphology of Lyp. sarothrurae shows some characteristics intermediate between those of the species rich genus Lyperosomum Looss, 1899 and Megacetabulum Oshmarin, 1964 that includes only 3 species. Due to the lack of clear morphological differences between the two genera, Megacetabulum is considered here as a junior synonym of Lyperosomum. Molecular phylogenetic analysis including Lyp. sarothrurae and all currently available partial sequences of the nuclear ribosomal 28S RNA gene of dicrocoeliid species is also included and its results are discussed.