Dissertation Research: The Effect of Stratocladistics on the Phylogenetic Analysis of Nassariine Gastropods

小行星9701745 蜗牛放置在亚科Nassariinae代表了当今蜗牛多样性的重要部分。 已知有数百种现存物种;此外，数百种物种出现在至少6000万年的化石记录中。 尽管有大量的物种和重要的化石记录，但对织纹螺目腹足类的基因学（系统发育史）还没有很好的了解。 解决这种系统发育历史的一种方法是在一次分析中使用活物种和化石物种的数据。 然而，来自化石的数据比来自活蜗牛的数据更不完整，这种相对不完整造成了问题。 因此，化石数据以前没有被包括在系统发育史重建的基础上现存的物种。 在这项研究中，桑德拉·卡尔森和博士生大卫·哈斯尔将重建Nassariinae亚科的系统发育史或家谱，结合对贝壳和解剖特征的分析以及对Nassariine物种化石历史的比较分析。 每一个主要的nassariine组的代表将从博物馆藏品中获得，并检查提供信息的外壳特征。 将从文献和标本解剖中获得代表性物种的解剖特征。 将记录每个主要群体最古老的化石。 将化石数据与基于特征的分析相结合的有用性将通过比较构建的包含和不包含时间化石数据的树进行测试。

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.