ARCHAEOPTERYX

Foreword 7
Acknowledgements 8
1. Introduction 9
2. Solnhofen – a Bavarian town known world-wide 11
2.1. The history of Solnhofen and its stone industry 11
2.2. Solnhofen stone in Art and Lithography 13
3. Solnhofen Plattenkalk – a geological excursion 15
3.1. The geological background 15
3.2. The Phenomenon of Time 16
3.3. Solnhofen in the Jurassic – a subtropical lagoon 19
3.4. The Sediment – Lime-rich mud on the bottom of a subtropical lagoon 20
3.5. The genesis of the Plattenkalk – a geological-paleoecological scenario 21
3.6. The Solnhofen climate – warm and dry 22
3.7. Geological history following the Solnhofen time 24
4. The Fossils of Solnhofen – a Window into the Jurassic World 26
4.1. Fossils – Speculations and Reality 26
4.2. Collectors and scientists – the origins of the scientific investigation of the Solnhofen Fossils 27
4.3. Fossilization and preservation 29
4.4. The Solnhofen fauna and flora 31
5. The Archaeopteryx specimens 39
5.1. How did the Solnhofen Urvogels become fossilized? 40
5.2. Nomenclature and Taxonomy 42
5.3. The feather 46
5.4. The London specimen 49
5.5. The Berlin specimen 60
5.6. The Maxberg specimen 77
5.7. The Haarlem specimen 85
5.8. The Eichstätt specimen 90
5.9. The Solnhofen specimen 98
5.10. The Munich specimen 104
5.11. The eighth specimen 113
5.12. The ninth specimen 114
5.13. The Thermopolis specimen 116
6. Archaeopteryx – the animal 123
6.1. Skeleton 123
6.2. Plumage 132
6.3. Physiology 136
6.3.1. The brain 136
6.3.2. Thermophysiology 137
6.3.3. Respiratory system 138
6.3.4. Reproduction and growth 139
6.3.5. Heart and circulatory system 140
6.4. Lifestyle 141
6.4.1. Terrestrial locomotion – walking, leaping, climbing 141
6.4.2. Could Archaeopteryx fly? 145
6.4.3. Diet 148
6.4.4. Habitat 149
6.5. Reconstructions 151
6.5.1. Skeletal reconstructions 151
6.5.2. Restoring the appearance in life 154
7. The Meaning of Archaeopteryx 157
7.1. Historical background 157
7.2. Archaeopteryx – a missing link? 158
7.3. Archaeopteryx – and the descent of the birds 160
7.3.1. The Thecodont Hypothesis 160
7.3.2. The Crocodile Hypothesis 160
7.3.3. Other candidates for “Ancestor of the birds” 160
7.3.4. The Theropod Hypothesis 162
7.4. Archaeopteryx – a bird? 166
7.5. Conclusions 167
8. The Evolution of Avian Flight – from the trees down or from the ground up? 168
9. Feathers – “invented” by dinosaurs? 174
10. The early evolution of birds – Is Archaeopteryx the ancestor of all birds? 179
Afterword 188
Bibliography 189
Museums and collections containing original specimens of Archaeopteryx 204
Index 205
Picture credits 208

Had the Solenhofen quarries been commissioned
- by august command -
to turn out a strange being à la Darwin -
it could not have executed the behest more handsomely -
than in the Archaeopteryx.

Hugh Falconer, 1863

As Charles Darwin’s friend, Hugh Falconer, put it upon examination of the London specimen, Archaeopteryx is the ultimate “missing link”, the cornerstone of a remarkable evolutionary transition - today witnessed by a multitude of fossils on both sides of an increasingly hazy dinosaur-bird divide - and Peter Wellnhofer is the Urvogel’s modern architect. He is the world’s authority on the celebrated 150-million-year-old bird and he has been so for over 30 years.

Known by only ten skeletal specimens and a single feather imprint discovered during the last 150 years, the priceless fossils of Archaeopteryx have had tremendous significance for our understanding of evolution, and their impact has gone way beyond science and into the social realm. Drawing from his immense familiarity with the fossils from the world-famous Solnhofen limestone, Wellnhofer narrates the history of discovery of Archaeopteryx, and the stories of the villages, collectors, and scholars whose fortunes became entangled with these discoveries. This book includes chapters on the geology and special preservation of the Solnhofen limestone, and interpretations of the environment inhabited by Archaeopteryx. The core of this book provides detailed descriptions and exquisite illustrations of each specimen. These and other chapters discuss the various interpretations regarding the size, growth and life history, plumage, physiology, life style, and other aspects of the paleobiology of this most ancient bird. Because Archaeopteryx has played a key role in discussions about bird origins, this book also addresses the rise of birds, highlighting the evidence in support of their dinosaurian ancestry, and the less settled issue of the beginning of avian flight. It closes with a summary of the early history of birds, which has been recently illuminated by countless new fossils from throughout the Cretaceous period.

As a student of early avian evolution, I have benefited enormously from Wellnhofer’s vast knowledge of the anatomy of Archaeopteryx, his detailed monographs on the Eichstätt, Solnhofen and Munich specimens, and his deep understanding of its historical context. His decades of involvement in the subject have made him part of the very same history he writes about. No one else could have written a book about Archaeopteryx with the same insider’s perspective and knowledge. Remarkably for someone so deeply involved in the subject, Wellnhofer’s approach to the universe of opinions about the natural history of the Urvogels betrays his magnanimous attitude; this even-handedness assures a fair coverage of the multitude of ideas that have been proposed about the life of Archaeopteryx.

There may never be another book on Archaeopteryx as detailed and comprehensive as this. Readers will undoubtedly find it to be a tour de force of one of the most significant fossils in the history of paleontology. On the 150th anniversary of the publication of The Origin of Species, I cannot think of a timelier book on paleontology than one about the legendary fossil bird that made such a grand case for Darwinism.

Luis M. CHIAPPE, Director
The Dinosaur Institute, Natural History Museum of Los Angeles County, USA
August 2009

Dr. Peter WELLNHOFER worked as a paleontologist at the Bayerische Staatssammlung für Paläontologie und Geologie in Munich and spent decades researching and examining the Urvogel findings himself. With this book, he presents the most complete documentation to date on the subject of Archaeopteryx in understandable language. In 1997, he was awarded the Werner and Inge Grueter Prize for Science Communication.