†Protorcula frydai Nuetzel, Blodgett & Stanley 2003

Nuetzel, Blodgett & Stanley 2003. Late Triassic gastropods from the Martin Bridge Formation (Wallowa Terrane) of northeastern Oregon and their paleogeographic significance. Neues Jahrbuch fuer Geologie und Palaeontologie Abhandlungen, 228(1), April 2003: 83-100