Phthanoperidinium zosimovichi Stotland in Andreeva-Grigorovich et al., 2011, p.39–40, pl.57, figs.1–9,2a,4a,9a; pl.58, figs.1a–d,2a–d,3a–d. Holotype: Andreeva-Grigorovich et al., 2011, pl.57, figs.1–9.2a,4a,9a. Age: early Oligocene.