Glorified Dinosaurs: The Origin and Early Evolution of Birds

  • Luis Chiappe
University of New South Wales Press/John Wiley: 2007. 272 pp. Aus$59.95/£38.95/US$56 0471247235 | ISBN: 0-471-24723-5
The rest is history: non-avian ancestors of birds such as the troodontid Mei long settled in familar postures. Credit: M. ELLISON

Dinosaurs: you have seen them, heard them (especially in spring) and you have probably eaten them. They did not all die out 65 million years ago as a result of an asteroid impact, as the media would generally have us believe. No, dinosaurs are all around us, and there are some 10,000 living species. They are, of course, birds. As Luis Chiappe so graphically illustrates in his book Glorified Dinosaurs, birds are small, feathered theropod dinosaurs.

In the past decade the evolution of birds from small meat-eating dinosaurs has been established beyond all reasonable doubt, thanks to some thrilling discoveries of new fossils and the radical reinterpretation of some others known since the late nineteenth century. Here, Chiappe presents a comprehensive and up-to-date summary of the exciting research that has revolutionized our understanding of the origin and evolution of the only other group of endothermic animals beside mammals that share our planet. In a lively, readable and accessible style, he takes the reader through the historical background, stresses the evolutionary relationships and the physical and functional changes from terrestrial predatory dinosaurs through to modern airborne birds. Chiappe deals with issues of controversy and debate in a clear and straightforward manner. He also offers his own point of view on several hot topics, notably the earliest appearance of modern orders of birds in the Mesozoic era, and how powered, flapping flight came about.

In the 1860s, T. H. Huxley concluded, on the limited fossil evidence then available, that birds were nothing more than glorified dinosaurs. But other views subsequently prevailed, notably that birds stemmed from early archosaurs, although there were no candidate fossils. Huxley's hypothesis was revived and really took off in the 1960s with the discovery by John Ostrom of a small, highly agile and remarkably bird-like predatory dinosaur that he named Deinonychus. Since then, a wealth of skeletal evidence has accumulated in support of the view that birds originated from within a group of small terrestrial theropods, now termed maniraptorans (the raptors of popular books and films). The sheer number of shared characters between maniraptorans and early birds is compelling and has formed the basis of repeated hypothesis testing by rigorous cladistic methods. The results have convinced all but the tiniest band of ornithologists.

An inevitable corollary of the dinosaur–bird relationship is that, as birds are feathered, their dinosaurian forebears must also have been so endowed. Indeed they were: some spectacular discoveries from the early 1990s onwards in Lower Cretaceous deposits in Liaoning province in China have revealed in exquisite detail a range of feathery coverings in several small theropod lineages. They range from simple filamentous protofeathers, which hint that the development of feathers was primarily for insulation, to small maniraptorans clad from head to knees in vaned contour feathers and tail plumes, just like modern birds. The remarkable preservation, which happened, like the burial of Pompeii, as a result of sudden inundation by volcanic ash and tuff, has provided the final pieces of evidence in the story of bird origins. Feathers were undoubtedly present a long way back down the theropod family tree but they are preserved only under these exceptional 'Lagerstätten' conditions.

One of the strong points of this book is that it is profusely illustrated, in full colour throughout, with more than 220 illustrations of fossils, including many of the spectacular Chinese 'dinobirds' and true bird fossils, and easy to follow diagrams and charts. If I have one gripe, it is that a number of the images of fossils are rather dark and do not do justice to the originals.

This book is bound to appeal not only to scientists, but also to anyone with an interest in dinosaurs, ornithology, evolution and natural history. Much of the content is available elsewhere only in the primary academic literature, so the book should prove an invaluable, compact source of information for university teachers. It is a coffee-table book rather than a textbook, but each chapter is selectively referenced, although a few more citations, particularly to some of the key Chinese specimens, would have enhanced the book's value as a reference source.

The exciting advances in this field certainly deserve to reach a wider public and professional educators, and this book does that superbly well. My attention was recently drawn to a current school textbook that stated there was little evidence to support the dinosaurian origin of birds and that they could equally well have evolved from pterosaurs. I can only hope that its author will read this book.