Kurzbeschreibung
The planktonic foraminifera have, for over forty years, been recognised to be the most valuable stratigraphic indices for marine sediments of Late Cretaceous and Cenozoic age. However, their evolutionary origins in the Jurassic and their development, morphological evolution and systematics in the Early Cretaceous have, until now, been poorly understood. This book illustrates for the first time all the published taxa known from the Jurassic, and clarifies and corrects their taxonomy. The taxonomy and stratigraphic distribution of the Early Cretaceous planktonic foraminifera are also revised, and all of the published species are illustrated, using the type specimens. The systematics of the Early Cretaceous forms are clearly set out, both for species and for genera: their evolution is explained as well as the ecological importance of the morphological changes they have undergone. Moreover, by analogy with the Recent Globigerinacea the palaeoenvironmental significance of these Early Cretaceous taxa is discussed. The book deals with 136 species belonging to 26 genera, five of which - Compactogerina, Haeuslerina (of the Jurassic), Lilliputianelloides; Claviblowiella and Planohedbergella (of the Cretaceous) - are new. Range charts are provided, as are extensive keys for the more important genera. Superbly illustrated, with 65 high-quality plates, this work will be an invaluable reference for all micropalaeontolists and biostratigraphers worldwide, with many species illustrated by SEM for the first time. This is the first book to collate all known information on the early evolutionary origins of the planktonic foraminifera.
Synopsis
The planktonic foraminifera are a group of protist zooplankton abundant in modern oceans which have been intensively studied in terms of their biology, ecology and distribution. The group ranges in time from the Mesozoic to the present day and has been widely used for palaeoceanographical, palaeoclimatological and, especially, stratigraphical applications. Their role as markers for biostratigraphical zonation and correlation underpins most drilling of ocean sedimentary sequences as well as hydrocarbon exploration work. As a result, the taxonomy and evolution of planktonic foraminifera are well-known for the later part of their history in the mid Cretaceous (Albian), late Cretaceous and Cenozoic (113Ma to present) when they had become particularly abundant and geographically widespread. This work presents evidence about the key period of evolutionary diversification in the Early Cretaceous, based on material from Russia, the Caucasus, Azerbaijan, Dagestan, Kazakhstan, Ukraine, the North Sea area, and North Africa (Tunisia and Algeria).
The origin and early development of the group in the Jurassic is reviewed which, together with the new knowledge of Early Cretaceous planktonic foraminifera, sets the scene for the well-known Late Cretaceous to recent evolutionary history of the group. The book serves as a guide to the recognition, evolutionary development and application of these important microfossils in the early and mid Mesozoic (220Ma-113Ma). It therefore provides the palaeobiological and evolutionary origins of a group which is well-known from the late Mesozoic (mid Cretaceous) onwards to the present. It should be of interest to all earth scientists concerned with the stratigraphy, micropalaeontology, palaeoceanography and palaeoclimatology of the Mesozoic, especially postgraduate students and professional micropalaeontologists, palaeoceanographers and hydrocarbon explorationists. By providing the critical early evolutionary history of one of the most important groups of fossil marine zooplankton which is extant in modern oceans, the book should also be of interest to evolutionary and marine biologists, and to other professionals interested in the geosphere-biosphere system through time.
