MORPHOLOGICAL AND MOLECULAR INVESTIGATIONS OF NAVICULOID DIATOMS. III. HIPPODONTA AND NAVICULA S. S.

Abstract

Molecular data confirm that the Navicula s. s., i.e. Section Lineolatae, is a monophyletic group within the Naviculales. In trees constructed from three molecular markers, Hippodonta was consistently placed as sister group to Navicula s. s. supporting its independence as a genus separate from Navicula. There were three distinct well supported clades within the Navicula s. s. but an investigation of their valve morphology did not reveal any morphological features that would support these clades.