original descriptionHasegawa, T. (1999). Planktonic foraminifera and biochronology of the Cenomanian-Turonian (Cretaceous) sequence in the Oyubari area, Hokkaido, Japan. <em>Palaeontological Research.</em> 3: 173-192., available online athttps://www.jstage.jst.go.jp/article/prpsj1997/3/3/3_3_173/_pdf[details] Available for editors [request]