The vertebrate integument arose about 450 million years ago as an 'armour' of dermal bony plates in small, jawless fish-like creatures, informally known as the ostracoderms. This book reviews the major changes that have occurred in the vertebrate integument from its beginnings to the present day. Critical questions concerning the origin, structure and functional biology of the bony integument are discussed and intrinsically linked to major steps in vertebrate evolution and phylogeny-the origin of jaws and the origin of teeth. The discussions include the origins of mineralization of major vertebrate skeletal components such as the dermatocranium, branchial arches and vertebral column. The advances that led to the origin of modern fishes and their phylogenetic development are reviewed and include the evolution of fins and replacement of the bony plates with several types of dermal scales. The evolution of reptiles saw a major transformation of the integument, with the epidermis becoming the protective outermost layer, from which the scales arose, while the dermis lay below it. The biological significance of the newly-evolved beta-keratin in reptilian scales, among the toughest natural materials known, is discussed in the context of its major contribution to the great success of reptiles and to the evolution of feathers and avian flight. The dermis in many vertebrates is strengthened by layers of oppositely oriented cross-fibres, now firmly entrenched as a design principle of biomechanics. Throughout the book conventional ideas are discussed and a number of new hypotheses are presented in light of the latest developments. The long evolutionary history of vertebrates indicates that the significance of the Darwinian concept of "survival of the fittest" may be overstated, including in our own mammalian origins and that chance often plays a major role in evolutionary patterns. Extensive illustrations are included to support the verbal descriptions.

Professor Theagarten Lingham-Soliar is in the Department of Life Sciences at the University of KwaZulu-Natal.

Introduction

The First Vertebrates, Jawless Fishes, the Agnathans
The Earliest Jawed Vertebrates, the Gnathostomes
Evolution of Modern Fishes: Critical Biological Innovations
Tetrapods and the Invasion of Land
Crucial Vertebrate Innovations
The Dinosaur Integument
Mammal-like Reptiles
Reptiles Return to the Sea.

Life in Water

The first jawless fishes. Evolution of dermal scales
Bony fishes. A primitive skin covered by dermal scales of various shapes and size
Cartilaginous fishes. Sharks and allies. Dermal denticles (placoid scales), reduces dragTransition to Life on Land
Amphibians
The Integument as a Selective Barrier
Early reptiles and the origin of reptilian scales (epidermal).Mammal-like reptiles
Origin of mammals
Origin of hairReturn to the sea
Ichthyosaur, placodonts, nothosaurs, plesiosaurs, mosasaurs
Evolution of high-speed aquatic locomotion in ichthyosaurs
The skin of ichthyosaurs compared with that of other modern high-speed, thunniform swimmers, tuna, dolphins and lamnid sharks. Archosaurs
The Dinosaurs.The big, the bad and the beautiful
Ornamentation and defense horns, crests and frills
Archaeopteryx, the first birdControversies
Origin of Birds
Origin of the feather.The Modern Vertebrate SkinModern Birds
Adaptation to life in the air
Structure and function of the modern feather.Nature s Dominant Structural Biomaterials
Collagen
KeratinDeath, Decay and Fossilization
How animals decompose
Slowing down the decay process in nature
Soft tissue - biological to geological preservation