Although dichotomous keys are commonplace in invertebrate zoology, they are less frequently used in identification of mollusks (with the notable exception of landsnails and to a certain extent freshwater bivalves). Malacologists and shell collectors, especially working on marine faunas, are generally comfortable with recognition” methods of identifying their specimens, AKA “hunt and pick” or “thumbing” through books and other literature, which in reality involves a high level of appreciation for and knowledge of family- and genus-level characters to narrow down possibilities. In other words, we might look at a specimen and say, “Aha! That looks like a venerid, so let’s look at this chapter [or these two books].” Two serious impediments to development of a successful key to bivalves is the tremendous diversity present in the class and the reliance at higher levels on anatomical characters, which are inconvenient to problematic in a key that, to be most useful, needs to concentrate on shell characters. Nevertheless, we recognize the need by some for this tool, and an attempt is underway to generate a key to marine bivalve families using single representatives of each family (admittedly losing much of the diversity present within families).
In the meantime, some existing published keys including bivalves are as follows (access to unpublished reports can be inquired from the project participants):
- Bayer, F. M. 1950. Preliminary key to the Florida species of Pecten. Unpublished report, 2 pp.
- Bogan, A. E. 2002. Workbook and key to the freshwater bivalves of North Carolina. Privately published, 101 pp., 10 pls.
- Bowers-Altman, J. 2002. Key to freshwater bivalves of New Jersey. Unpublished report, 4 pp.
- Clarke, A. H., Jr., & C. O. Berg. 1959. The freshwater mussels of central New York, with an illustrated key to the species of northeastern North America. Cornell University, Agricultural Experimental Station, Memoir 367, 79 pp.
- Davis-Strickland, E. R., & S. K. Donovan. 1993. Key for field identification of rudist bivalves from the Cretaceous of Jamaica. Caribbean Journal of Science, 29(3-4): 267-271.
- Eaton, L. undated. A partial key to the pelecypods of Florida. Unpublished report, ca. 100 pp.
- Keen, A. M., & E. Coan. 1974. Marine molluscan genera of western North America, an illustrated key. Stanford University Press, Stanford, California, 208 pp.
- Kraeuter, J. 19??. Key to some marime gastropods [and bivalves] of Virginia. Unpublished manuscript, 32 pp.
- Smith, D. G. 1986. Keys to the freshwater macroinvertebrates of Massachusetts (1): Mollusca Pelecypoda (clams, mussels). Massachusetts Department of Environmental Quality Engineering, iii + 53 pp.
- Smith, D. G. 1991. Keys to the freshwater macroinvertebrates of Massachusetts, version 1.0. D. G. Smith, Amherst, Massachusetts, iv + 236 pp.
- Weiss, H. M. 1995. Marine animals of southern New England and New York: identification keys to common nearshore and shallow water macrofauna. State Geological and Natural History Survey of Connecticut, Bulletin 115, various pagination.