Characteristics of Radiolarian Evolution in the Campanian and Maastrichtian and Prospects for Detailed Stratigraphy

Abstract

The Campanian and Maastrichtian radiolarian assemblages are known from many regions of the Tethyan Superrealm. Unfortunately, only some of them are reliably dated and completely studied as paleontological assemblages. The analysis of evolution of radiolarians is based on Campanian to Maastrichtian assemblages from Crimea, Cyprus, and Serbia properly dated and studied in detail with addition of data from California, Turkey, the World Ocean, and other regions. It is concluded that renewal of assemblages took place in the Campanian and Maastrichtian relatively slowly. The biodiversity was slowly reduced at the generic level. The history of radiolarian evolution in the end of the Late Cretaceous can be subdivided to several stages: late Santonian–early Campanian, early Campanian–late Campanian, late Campanian–early Maastrichtian, and late Maastrichtian.