The graptolites constitute one of the geologically most useful taxonomic groups of fossils for dating rock successions, understanding paleobiogeography and reconstructing plate tectonic configurations in the Lower Palaeozoic. Graptolites were largely planktic, marine organisms, and as one of the first groups that explored the expanses of the world’s oceans are vital for understanding Palaeozoic ecology. They are the best and often the only fossil group for dating Lower Palaeozoic rock successions precisely. Thousands of taxa have been described from all over the planet and are used for a wide variety of geological and palaeontological (biological) research topics. The recent recognition of the modern pterobranch Rhabdopleura as a living benthic graptolite enables a much better understanding and interpretation of the fossil Graptolithina.
In the decades since the latest edition of the Graptolite Treatise, the enormous increase of knowledge on this group of organisms has never been synthesised in a compelling and coherent way, and information is scattered in scientific publications and difficult to sort through. This volume provides an up-to-date insight into research on graptolites. Such research has advanced considerably with the use of new methods of investigation and documentation. SEM investigation and research on ultrastructure of the tubaria has made it possible to compare extant and extinct taxa in much more detail. Cladistic interpretation of graptolite taxonomy and evolution has advanced the understanding of this group of organisms considerably in the last two decades, and has highlighted their importance in our understanding of evolutionary processes. This book will show graptolites, including their modern, living relatives, in a quite new and fascinating light, and will demonstrate the impact that the group has had on the evolution of the modern marine ecosystem.
This book is aimed not only at earth scientists but also at biologists, ecologists and oceanographers. It is a readable and comprehensible volume for students at the MSc level, while remaining accessible to undergraduates and non-specialists seeking up-to-date information about this fascinating topic in palaeobiology.
List of Contributors vii
1 Graptolites: An Introduction 1
Jan Zalasiewicz and Jörg Maletz
2 Biological Affinities 15
3 Construction of Graptolite Tubaria 31
Jörg Maletz, Alfred C. Lenz and Denis E. B. Bates
4 Paleoecology of the Pterobranchia 50
Jörg Maletz and Denis E. B. Bates
5 Graptolites as Rock Components 76
6 Graptolites and Stratigraphy 94
7 Taxonomy and Evolution 111
8 Bound to the Sea Floor: The Benthic Graptolites 124
9 The Planktic Revolution 139
10 Early Ordovician Diversity Burst 153
Jörg Maletz and Yuandong Zhang
11 The Biserial Graptolites 181
12 The Retiolitid Graptolites 207
Jörg Maletz, Denis E. B. Bates, Anna Koz³owska and Alfred C. Lenz
13 The Monograptids 221
14 Collection, Preparation and Illustration of Graptolites 244
Denis E. B. Bates and Jörg Maletz
15 History of Graptolite Research 254
Graptolites might have lost some of their utilitarian appeal even to Palaeozoic biostratigraphers but they have gained in palaeobiological interest over the last few decades. Graptolite Paleobiology marks a useful point in graptolite studies when it is appropriate to take stock of what has been achieved.
Arguably the last time this happened was in 1955 when Bulman wrote the first edition of the graptolite volume of the Treatise. Maletz and contributors are to be congratulated on pulling together such a considerable body of research, stretching back nearly 300 years, and for producing such a beautifully illustrated and informative book, which deserves a place in every geological library.
It was 1735 when Linnaeus first noticed this somewhat enigmatic group of fossils. He coined the name Graptolithus, derived from the Greek via modern Latin and meaning 'written rock', although he thought that they were the fossil remains of plants.
Maletz reviews the progress that has been made, especially since the early decades of the 19th Century. At that time, graptolite studies were broadly divided between a European academic tradition with a biological approach to the fossils (especially in Sweden and subsequently Poland), whereas in Britain the approach was more utilitarian and biostratigraphical. Although there was of course a more general international interest in the taxonomy and evolution of the graptolites, this progressed quite independently of any need to understand their biological affinities. Conodont research had a similar history of development.
Only in the mid-20th Century did palaeobiological and biostratigraphical approaches begin to merge. As with that other group of enigmatic marine Palaeozoic fossils (conodonts), the underlying biological problem with graptolites was the zoological identity of the graptolite organism. Although microscope studies of chemically isolated specimens by Swedish palaeontologists had already presented clues as to the graptolites’ pterobranch affinity, it took another 70 years before the new technologies of scanning and transmission electron microscopy revealed the true connection.
Despite a diminishing number of researchers, great progress has been made across the whole range of graptolite studies in recent decades. Palaeobiology cannot stand alone without support from taxonomic and evolutionary research. As Maletz shows so clearly, all have benefited from the ability to examine chemically isolated specimens by electron microscopy both SEM and TEM. Crowther’s ‘breakthrough’ recognition in the late 1970s of the nature and origin of cortical ‘bandages’ in the structure of the graptolite stipe led the way.
Much of the graptolite research literature is notoriously scattered and often hard to access but Graptolite Paleobiology provides an excellent digest and is essential reading for all advanced students.
Reviewed by Douglas Palmer
GRAPTOLITE PALEOBIOLOGY by JÖRG MALETZ. Wiley Blackwell. 2017. ISBN 978-1-118-51561-7. 323pp. List price: £130.00 (hbk) £45.00 (sbk) e-book: £40.99 W: www.wiley.com/en-gb/Graptolite+Paleobiology-p-9781118515617