1937a Thalassoceras biforme Gerasimov: 17, pl.1 fig.8.
     1938  Prothalassoceras biforme.-Ruzhentsev: 253, pl.3 fig. 6-8.
     1948  Prothalassoceras biforme var. latilobata Maksimova: 25, pl.3 fig.3,4.
     1951  Prothalassoceras biforme.-Ruzhentsev: 103, pl.6 fig.7.
     1986  Prothalassoceras biforme.-Bogoslovskaia: 60, pl.37 fig.11, pl.56 fig.17.
     1995  Prothalassoceras biforme.-Bogoslovskaia, Leonova & Shkolin: 298, figs. 5.28, 5.29, 10.8.

Fig. see TAX5217 H (suture).