Further notes on the turrilitid ammonoids from Hokkaido : Part 2 (Studies of the Cretaceous ammonites from Hokkaido and Sakhalin-XC)

Abstract

Six species of Turrilites, two species of Mesoturrilites and two species of Mariella are described on the basis of material from the lower and middle parts of the Cenomanian (mid-Cretaceous) in the central and northwestern Hokkaido. Several of them are well known for their worldwide distribution and occur in Hokkaido at correlatable stratigraphic levels. Three new species, Turrilites complexus, T. miroku and Mesoturrilites pombetsensis, are established, showing interesting but still questionable relationships with some previously known ones. Two species in open nomenclature require further study.