A phylogenetic analysis of the synurophyceae using molecular data and scale case morphology

Abstract

The phylogeny of the Synarophyceae was investigated by parsimony analysis of scale case characters and small-subunit (18s) ribosomal RNA (rRNA) sequence data. Analysis of 1 enstigmatophycean (outgroup), 3 chrysophycean, and 10 synurophycean 18S rRNA sequences corroborated the inference from ultrastructural information that the Synurophyceae is a monophyletic assemblage. Tessellaria volvocina, which had been tentatively proposed as a member of the Synurophyceae, was confirmed as the earliest lineage within the Synurophyceae by both the molecular analysis and an evaluation of published ultrastructural data. A second set of analyses investigated the relationships among Tessellaria volvocina, 6 ..