New belemnite records from the Mitarai Formation, Tetori Group, Japan: delimitation of the Jurassic-Cretaceous boundary in the Japanese Islands

Traditional faunal elements for zoning the uppermost Jurassic‒lowermost Cretaceous stratigraphic interval in Tethyan regions, i.e., ammonites and calpionellids, are either lacking in the boreal regions at that time, or are of generally low diversity and endemic compositions. Consequently, recognition of Jurassic-Cretaceous boundary interval sections has been hindered in many areas of the boreal regions, as well as some lower latitude intermediate areas, such as the Japanese Islands.