The new species is a member of an apparently monophyletic group within the genus that includes R. flexile, R. walga, R. himanturi, R. burgeri, R. euzeti, R. hawaiiensis, R. urobatidium, R. paratrygoni, R. ditesticulum, R. tetralobatum, R. margaritense, R. biorchidum, and R. spinicephalum. All of these species have bothridia with medial longitudinal septa, a constriction at mid-bothridium, and, ...