Phylogenetic relationships among species of Glabratellidae (Foraminifera) inferred from ribosomal DNA sequences: Comparison with morphological and reproductive data

摘要

Foraminiferal genera and species have long been classified primarily using morphological characters of their tests. However, morphology of a foraminiferal test may sometimes be influenced by the ambient environment. It is, thus, difficult to determine which factors, genetic or ecophenotypic, mainly control morphological variations in foraminifera. Moreover, some foraminiferal species change morphology during ontogeny and/or in different phase of reproduction. For example, some species have been found to be simple reproductive stages of the same species (Nyholm 1961). Therefore, morphologically-based identification may be inadequate and inappropriate for estimating phylogenies.