Bulletin of the Mizunami Fossil Museum

Bulletin of the Mizunami Fossil Museum No. 48

Diatoms from mudstone produced plant fossils of the Toki Lignite-bearing Formation, Mizunami City, Gifu Prefecture, Japan

Hiroyuki Tanaka

Published: 2021/12/26   Page: 103106

The diatoms of the early Miocene Toki Lignite-bearing Formation distributed around Mizunami City, Gifu Prefecture, Japan were investigated. The formation mainly consists of mudstone containing plant fossils and an abundance of Aulacoseira taxa, such as Aulacoseira praegranulata var. praeislandica (Jousé) Moisseeva and A. praegranulata var. praeangustissima (Jousé) Moisseeva. Aulacoseira praegranulata var. praeislandica has three forms consisting of densely areolated, coarsely areolated and/or thickly formed valves. Three forms of Aulacoseira praegranulata var. praeislandica and associated taxa are showed in LM photographs.