Recent progress in Cretaceous ammonoid paleontology: Especially focusing on the Northern Pacific region

Abstract

This paper reviews the Cretaceous ammonoid paleontology mainly in the North Pacific region, especially for recent publications. The species diversity changes through Cretaceous and its relevant articles are first reviewed. The review is continued from the points of view of the morphological analyses of shell shape, the relationship between ammonoid fauna and lithofacies, the isotopic analyses of ammonoid shells, the relationship with other organisms, and taphonomy etc., for normally coiled and heteromorphic ammonoids, respectively. Finally, the characteristic of ammonoid diversity change in North Pacific region and the ammonoid extinction around the Cretaceous/Paleogene boundary are reviewed.