Preliminary phylogenetic analysis of the bivalve family Galeommatidae

A preliminary phylogenetic analysis of species assigned to the ill-defined family Galeommatidae, plus selected others, was attempted in an effort to clarify the relative value of various systematic characters. Aspects of dealing with large numbers of equally parsimonious trees in cladistic analyses and intrinsic problems of analyses based on unordered multistate characters are addressed briefly. The analysis (Hennig86, implicit enumeration) of 18 characters with 46 character states for 20 species yielded 164 equally parsimonious trees (length 52, ci 53, ri 72), displaying five distinctly different branching patterns.Separate consensus trees were produced for the five groups. Of the five topologies, one is considered most likely in an evolutionary context, and is discussed in detail.