Taxonomy, morphology and phylogeny of the Neogene diatom zonal marker species in the middle-to-high latitudes of the North Pacific.

Abstract

Based on both light microscopic and electron microscopic observations, taxonomic refinements of most of the Neogene diatom zonal markers of the middle-to-high latitudes of the North Pacific produce a firmer basis for its zonal frameworks. Denticulopsis, by far the most important genus biostratigraphically, is subdivided into Crucidenticula n.gen., Denticulopsis emend., and Neodenticula n.gen., based on submicroscopic features and phylogenetic relationships. All species belonging to the three genera recognized in Japan and its environs are discussed and illustrated in detail. The plicated members of genus Coscinodiscus, including C. temperei and C. yabei, are transferred to Thalassiosira. In total, 38 species are described in this paper.-from AuthorsJapan new taxons