Graptolite Paleobiology

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) "Maletz and contributors are to be congratulated on pulling together such a considerable body of research... a beautifully illustrated and informative book." (Geoscientist, March 2018)