Aulacoseira houki, a new Early Miocene freshwater diatom from Hiramaki Formation, Gifu Prefecture, Japan

Abstract

Aulacoseira houki sp. nov. is described from an Early Miocene freshwater sediment of the Hiramaki Formation located in southern Gifu Prefecture, Japan. The species has a round valve face with areolae, a relatively short mantle with straight rows of areolae and a particularly distinguishing location of rimoportulae on both the valve face and on the mantle near the ringleist. The authors were unable to find any taxon that had this combination of these characteristics and accordingly proposed it as a new species. Light and scanning electronic microscope photographs are given.

Keywords:

• Aulacoseira houki
• Early Miocene
• freshwater diatom
• Japan