9701745 CARLSON Snails placed in the subfamily Nassariinae represent a significant portion of present-day snail diversity. Hundreds of living species are known; in addition, hundreds of species appear in a fossil record of at least 60 million years in age. The geneaology (phylogenetic history) of nassariine gastropods is not well understood, despite the large number of species and significant fossil record. One approach to resolving this phylogenetic history includes using data from both living and fossil species in a single analysis. However, the data from fossils are more incomplete than the data from living snails, and this relative incompleteness has caused problems. Consequently, fossil data have previously not been included in phylogenetic history reconstructions based on extant species. In this research, Sandra Carlson and doctoral candidate David Haasl will reconstruct the phylogenetic history or family tree of the subfamily Nassariinae, combining both an analysis of shell and anatomical traits and a comparative analysis of the fossil history of nassariine species. Representatives of each major nassariine group will be obtained from museum collections and examined for informative shell traits. Anatomical traits of representative species will be obtained from the literature and from dissections of specimens. The oldest fossil occurrence of each major group will be noted. The usefulness of combining fossil data with a trait-based analysis will be tested by comparing trees constructed both with and without the inclusion of temporal fossil data.
