An interesting mid-Cretaceous ammonite from Hokkaido : Studies of the Cretaceous ammonites from Hokkaido and Sakhalin-LXXIX

Abstract

In this paper a fairly well-preserverd ammonite is shortly described to show its interesting characters. It is provisionally referred to Bhimaites and regarded as a new species. Since it is small even at the adult stage and has a probable trace of lappet, it may represent a microconch of a dimorphic pair. It was found solely from the upper part of the Albian in the Soeushinai area of Hokkaido. More material is, however, required to clarify the extent of variation, to confirm the idea of dimorphism and to know the stratigraphic range and geographic distribution of this species.