(Seo, Rim, Lee, 1964) sensu Pyo , 2014 (Trematoda: Diplostomidae Poirier, 1886): morphology, life cycle, and phylogenetic relationships.

Furcocercariae of the genus Railliet, 1919 (Diplostomidae Poirier, 1886) were found in freshwater snails Starobogatov, 1957 (Planorbidae Rafinesque, 1815) collected from three localities in the Russian southern Far East. For the trematodes from each locality, frogs played the role of the second intermediate host, and rats were the definitive host. Chickens were insusceptible to infection. The morphological and molecular data obtained for these trematodes indicated they were representatives of the same species. The experimentally-derived adult individuals were morphometrically similar to the East Asian (Seo, Rim, Lee, 1964), Oschmarin, 1963, Chai and Shin, 2002, and Shin et al., 2008. Analysis of available data on the life cycle, developmental stage morphology, and molecular genetic characteristics of East Asian revealed a lack of information for objective assessment of the species status of neodiplostomula found in the East Asia region. Based on the considerations above and the data for the marker, we named the trematode (Seo, Rim, Lee, 1964) sensu Pyo , 2014. In a phylogenetic reconstruction based on nuclear and mitochondrial markers, neodiplostomulas clustered into geographically related groups: South American, North American, European, and East Asian, with the former occupying an external position in the tree, which may indicate South America as a center of speciation.