This mentioned taxonomy is an attempt to make an conclusive assignment from the different classifications of various scientists. Because the taxonomy may change due to the latest investigative methods and other findings, our map is a guide only.
W. P. Woodring, 1982 - Geology and paleontology of canal zone and adjoing parts of Panama: Description of Tertiary mollusks (Pelecypods: Propeamussiidae to Cuspidariidae). - United States Geological Survey Professional Paper (306), - (serial monograph, )
J. W. Durham, 1944 - Megafaunal zones of the Oligocene of northwestern Washington - University of California Publications in Geological Sciences (27), 101 -212 (journal article, English)
J. A. Gardner, 1943 - Mollusca from the Miocene and Lower Pliocene of Virginia and North Carolina - United States Geological Survey Professional Paper (199), - (serial monograph, English)
C. J. Maury, 1936 - - Monographias do Servico Geologico E Mineralogico (11), 1-283 (serial monograph, English)
U. S. Grant, IV, 1931 - Catalogue of the Marine Pliocene and Pleistocene Mollusca of California - Memoirs of the San Diego Society of Natural History (1), 1-1036 (serial monograph, English)
F. Hodson, 1931 - Some Venezuelan Mollusks - Bulletins of American Paleontology (16), 1-46 (serial monograph, English)
A. A. Olsson, 1931 - Contributions to the Tertiary Paleontology of Northern Peru: Part 4, The Peruvian Oligocene - Bulletins of American Paleontology (17), - (journal article, English)
A. A. Olsson, 1930 - Contributions to the Tertiary Paleontology of Northern Peru: Part 3, Eocene Mollusca - Bulletins of American Paleontology (17), 1-164 (serial monograph, English)
T. Nagao, 1928 - Palaeogene fossils of the Island of Kyushu, Japan Part II - Science Reports of the Tohoku Imperial University (12), 11-140 (journal article, English)
W. A. Price, 1928 - A new fauna from the Cook Mountain Eocene near Smithville, Bastrop County, Texas - Journal of Paleontology (2), 20-31 (journal article, English)
M. A. Hanna, 1927 - An Eocene invertebrate fauna from the La Jolla Quadrangle, California - University of California Publications Bulletin of the Department of Geological Sciences (16), 247-398 (journal article, English)
B. L. Clark, 1927 - The geology and paleontology of the type section of the Meganos Formation (lower Middle Eocene) of California - University of California Publications in Geological Sciences (17), 63-142 (serial monograph, English)
W. H. Dall, 1916 - A contribution to the invertebrate fauna of the Oligocene beds of Flint, River - Proceedings of the United States National Museum (51), 487-524 (journal article, English)
B. L. Clark, 1915 - Fauna of the San Pablo group of middle California - University of California Publications Bulletin of the Department of Geology (8), 385-572 (journal article, English)