Paleogene fossil birds, edited by Gerald Mayr. Springer-Verlag, Berlin, 2009. No. of pages: 262. ISBN 978-3-540-89627-2
PALEOGENE FOSSIL BIRDS, edited by Gerald Mayr. Springer-Verlag, Berlin, 2009. No. of pages: 262. Price: € 119–95. ISBN 978-3-540-89627-2 (hardback).
H.J.M. Meijer*, * National Centre for Biodiversity—Naturalis, Postbus 9517, NL-2300 RA Leiden, The Netherlands
When using the term ‘fossil birds’, images spring to mind of Archaeopteryx or the beautifully preserved primitive birds of Liaoning province of China. Their significance to our understanding of evolution can hardly be overestimated, but there is a whole lot more to fossil birds than these critters. It is generally agreed that modern birds (Neornithes) have their origin in the Late Cretaceous and that the first split in crown-group birds, between the Palaeognathae (ratites and allies) and Neognathae (all other birds), occured before the K/T transition. However, it was after the extinction of the dinosaurs that major radiations of Neornithes took place. New species of Cenozoic birds are being described every year, and renowned fossil localities in Europe and North America have contributed substantially to the fossil bird record of the Paleogene; the number of higher-level bird taxa now rivals that of mammals. Nevertheless, Cenozoic birds remain significantly under-represented in the field of vertebrate palaeontology. In Paleogene Fossil Birds Gerald Mayr sets the (fossil) record straight and presents the first review of the early diversification of modern birds.
The book kicks off with an overview of the most important localities for Paleogene birds. In Europe, Paleogene bird localities are numerous and mostly Eocene in age (such as Messel near Darmstad, Germany, and the London Clay in southern England), whereas localities in North America yield fossil bird remains from the Paleocene through to the Oligocene. Little is still known about Paleogene Neornithes from South America, Africa, Asia and Australasia.
The greater part of the book of consists of a detailed systematic treatment of the major bird clades present in the Paleogene. Compiling these chapters must have been a tremendously time-consuming task, as many Paleogene species have a confusing history; their taxonomy was repeatedly revised as scattered finds of isolated bones were identified and reidentified several times. Also, a number of bird clades are known only from the Palaeogene, for example, the giant Presbyornithidae and Gastornithidae, and often show morphologies intermediate to several modern-type birds groups. Mayr has composed the first review of the Paleogene avian fossil record that is comprehensive and summarises the current hypotheses regarding the early diversification of Cenozoic birds. For anyone who has become dazed by the wealth of information, the appendix provides a handy summary of the temporal and geographical distribution of major bird groups throughout the Paleogene. Although the information of the book will undoubtedly be falsified, confirmed and extended as more birds are discovered and described, it becomes clear that the Paleogene hosted bird faunas that were as diverse in morphology and ecology as modern day avifaunas.
Despite the extensive and detailed overview of the various bird clades, I particularly enjoyed the concluding chapter. It is here that Mayr explores the biogeography and evolution of Neornithes, and the effects of the rise of mammals on Paleogene avifaunas. After the demise of the dinosaurs, the absence of carnivorous mammals in the early Paleocene gave way to the evolution of large flightless birds such as penguins and the giant terror birds of South America. Also, the Paleogene non-passerine insectivores may have been severely impacted by the rise of Passeriformes (songbirds) in the Early Oligocene.
Mayr has provided us with the much needed first, impressively comprehensive review of birdlife in the Paleogene. Although modest in appearance (it could have done with some nice colour photographs and reconstructions of extinct taxa such as the giant pseudo-toothed birds), this book is a must-have for any palaeo-ornithologist. The non-avian vertebrate palaeontologist and general reader, however, may be more interested in the final chapter on evolutionary and biogeographical patterns of Paleogene birds. Now, if only someone would write a similarly comprehensive book on the remaining half of the Cenozoic.