Until John Ostrom rekindled the idea that there was a link between birds and theropod dinosaurs, the origin of birds was very much in dispute, with some researchers suggesting their origins lie within other types of archosaurian reptiles. However, most researchers now believe that the origins of birds lie within a group of theropod dinosaurs that evolved during the Mesozoic Era. More importantly, the debate is now centred on the sequence of evolutionary events that gave rise to early birds within theropods, and the widespread use of phylogenies, bio-molecular work and morphological analysis have taken this concept into new and exciting directions. This has been possible due to the discoveries of bird fossils in almost every continent, in which exquisite feather and other anatomical details have been preserved. Living Dinosaurs provides a review of our present understanding of bird origins, and provides a long overdue link between avian palaeontology and avian evolutionary biology. The book is divided into four sections. The first deals with the early ancestry of birds, from Archaeopteryx to the diverse pre-modern bird clade of enantiornithes, which now number 60 taxa and have been found in every continent except Antarctica. This section includes a thorough review of avian divergences in the Mesozoic, and explores the conditions as to why there was a major diversification in the Cretaceous. The second section provides a detailed overview of the fossil record, the contribution of palaeontology to ornithology and the diversity of modern birds. Important contributions include a review of Sphenisciformes (penguins), Phorusrhacidae (terror birds), and the Odontopterygiformes (pseudo-toothed birds). The latter were giant seabirds with huge bills adorned with bony processes (pseudo-teeth). The phylogeny and diversification of Passerines (song birds), which make up more than half of all known modern birds, are reviewed, and the use of molecular work is beginning to untangle their complex and as yet unresolved phylogenies. The late Brad Livezey, an expert and leading figure in bird phylogeny based on morphological characters, provides an overview of the progress and obstacles that can blight phylogenetics of modern birds. The third section concentrates on the features that have contributed to the success of living forms. This includes contributions on the development of flapping flight, evolution of the avian brain and diversification of neornithine birds through the K–Pg boundary. The fourth section addresses the future of avian diversity when faced with increasing anthropogenic pressure and climate change. All birds known from the fossil record and addressed in this book became extinct due to natural events, and over a comparatively long period of time. That modern birds are undergoing a human-induced mass extinction event, unprecedented in the speed in which it is taking place, cannot be denied, and the consequences of our present actions can only be guessed at.
Living Dinosaurs covers a broad spectrum, from the bio-molecular aspects of avian biology as well as the anatomy of dinosaurs. But this book is not for the layman. For example, the character matrix in the ‘Pre-modern birds’ chapter covers a total of 25 pages, and somewhat complex graphs and cladograms are used throughout the book. However, this book is a must for those interested in the origins of birds, either in a palaeontological or an evolutionary biological context. It not only covers present research in detail, but also lays foundations for future work and the likely direction that this will take.