The Vertebrate Integument Volume 2

The emphasis in this volume is on the structure and functional design of the integument. The book starts with a brief introduction to some basic principles of physics (mechanics) including Newton’s Three Laws of Motion. These principles are subsequently used to interpret the problems animals encounter in motion. It is in only the last 40 or so years that we have begun to understand how important a role the integument plays in the locomotion of many marine vertebrates. This involves the crossed-fiber architecture, which was first discovered in a classic study on nemertean worms. As a design principle we see that the crossed-fiber architecture is ubiquitous in nature. Research on some of the most dynamic marine vertebrates of the oceans – tuna, dolphins and sharks, and the extinct Jurassic ichthyosaurs – shows precisely how the crossed-fiber architecture contributes to high-speed swimming and (in lamnid sharks) may even aid in energy conservation. However, this design principle is not restricted to animals in the marine biota but is also found as far afield as the dinosaurs and, most recently, has been revealed as a major part of the microstructure of the most complex derivative of the integument, the feather. We see that a variety of phylogenetically diverse vertebrates take to the air by using skin flaps to glide from tree to tree or to the ground, and present detailed descriptions of innovations developed in pursuit of improved gliding capabilities in both extinct and modern day gliders. But the vertebrate integument had even greater things in store, namely true or flapping flight. Pterosaurs were the first vertebrates to use the integument as a membrane in true flapping flight and these interesting extinct animals are discussed on the basis of past and cutting-edge research , most intriguingly with respect to the structure of the flight membrane. Bats, the only mammals that fly, also employ integumental flight membranes. Classic research on bat flight is reviewed and supplemented with the latest research, which shows the complexities of the wing beat cycle to be significantly different from that of birds, as revealed by particle image velocimetry. The book’s largest chapter is devoted to birds, given that they make up nearly half of the over 22,000 species of tetrapods. The flight apparatus of birds is unique in nature and is described in great detail, with innovative research highlighting the complexity of the flight structures, bird flight patterns, and behavior in a variety of species. This is complimented by new research on the brains of birds, which shows that they are more complex than previously thought. The feather made bird flight possible, and was itself made possible by β-keratin, contributing to what may be a unique biomechanical microstructure in nature, a topic discussed in some depth. A highly polarized subject concerns the origin of birds and of the feather. Alleged fossilized protofeathers (primal simple feathers) are considered on the basis of histological and taphonomic investigative studies in Chapter 6. Finally, in Chapter 7 we discuss the controversies associated with this field of research. Professor Theagarten Lingham-Soliar works at the Nelson Mandela Metropolitan University, Port Elizabeth and is an Honorary Professor of Life Sciences at the University of KwaZulu-Natal.

The emphasis in this volume is on the structure and functional design of the integument. The book starts with a brief introduction to some basic principles of physics (mechanics) including Newton’s Three Laws of Motion. These principles are subsequently used to interpret the problems animals encounter in motion. It is in only the last 40 or so years that we have begun to understand how important a role the integument plays in the locomotion of many marine vertebrates. This involves the crossed-fiber architecture, which was first discovered in a classic study on nemertean worms. As a design principle we see that the crossed-fiber architecture is ubiquitous in nature. Research on some of the most dynamic marine vertebrates of the oceans – tuna, dolphins and sharks, and the extinct Jurassic ichthyosaurs – shows precisely how the crossed-fiber architecture contributes to high-speed swimming and (in lamnid sharks) may even aid in energy conservation. However, this design principle is not restricted to animals in the marine biota but is also found as far afield as the dinosaurs and, most recently, has been revealed as a major part of the microstructure of the most complex derivative of the integument, the feather. We see that a variety of phylogenetically diverse vertebrates take to the air by using skin flaps to glide from tree to tree or to the ground, and present detailed descriptions of innovations developed in pursuit of improved gliding capabilities in both extinct and modern day gliders. But the vertebrate integument had even greater things in store, namely true or flapping flight. Pterosaurs were the first vertebrates to use the integument as a membrane in true flapping flight and these interesting extinct animals are discussed on the basis of past and cutting-edge research , most intriguingly with respect to the structure of the flight membrane. Bats, the only mammals that fly, also employ integumental flight membranes. Classic research on bat flight is reviewed and supplemented with the latest research, which shows the complexities of the wing beat cycle to be significantly different from that of birds, as revealed by particle image velocimetry. The book’s largest chapter is devoted to birds, given that they make up nearly half of the over 22,000 species of tetrapods. The flight apparatus of birds is unique in nature and is described in great detail, with innovative research highlighting the complexity of the flight structures, bird flight patterns, and behavior in a variety of species. This is complimented by new research on the brains of birds, which shows that they are more complex than previously thought. The feather made bird flight possible, and was itself made possible by β-keratin, contributing to what may be a unique biomechanical microstructure in nature, a topic discussed in some depth. A highly polarized subject concerns the origin of birds and of the feather. Alleged fossilized protofeathers (primal simple feathers) are considered on the basis of histological and taphonomic investigative studies in Chapter 6. Finally, in Chapter 7 we discuss the controversies associated with this field of research. Professor Theagarten Lingham-Soliar works at the Nelson Mandela Metropolitan University, Port Elizabeth and is an Honorary Professor of Life Sciences at the University of KwaZulu-Natal.

The integument plays an important role in the survival of meta zoans by separating and protecting them from a hostile environ ment. Its function ranges from protection against injury and in fection, participation in the regulation of body temperature and water balance, to respiratory activity, monitoring of the environ ment and production of signals related to behaviour. All these result from specific structural, biochemical and physiological properties of intra-and extracellular components of the integu ment. Thus its characterization can be best accomplished by a multidisciplinary approach with authors specialized in different fields of science. This multi-author book, in two volumes, provides an up-to date survey of the literature. The first volume deals with the integument of invertebrates, the second with that of vertebrates, both organized primarily on a phylum basis. As the level of knowledge on the integument of phyla differs considerably, the information provided is correspondingly either limited or con densed. For some of the smaller groups of invertebrates little information is available, as often only a few electron micrographs are to be found in the literature ; on the other hand, from the large body of knowledge existing for vertebrates, particularly for mammals, no complete overview can be provided, but publica tions giving access to further information have been reviewed critically.

The integument plays an important role in the survival of meta zoans by separating and protecting them from a hostile environ ment. Its function ranges from protection against injury and in fection, participation in the regulation of body temperature and water balance, to respiratory activity, monitoring of the environ ment and production of signals related to behaviour. All these result from specific structural, biochemical and physiological properties of intra-and extracellular components of the integu ment. Thus its characterization can be best accomplished by a multidisciplinary approach with authors specialized in different fields of science. This multi-author book, in two volumes, provides an up-to date survey of the literature. The first volume deals with the integument of invertebrates, the second with that of vertebrates, both organized primarily on a phylum basis. As the level of knowledge on the integument of phyla differs considerably, the information provided is correspondingly either limited or con densed. For some of the smaller groups of invertebrates little information is available, as often only a few electron micrographs are to be found in the literature ; on the other hand, from the large body of knowledge existing for vertebrates, particularly for mammals, no complete overview can be provided, but publica tions giving access to further information have been reviewed critically.

The integument plays an important role in the survival of meta zoans by separating and protecting them from a hostile environ ment. Its function ranges from protection against injury and in fection; partlcipation in the regulation of body temperature and water balance, to respiratory activity, monitoring of the environ ment and production of signals related to behaviour. All these result from specific structural, biochemical and physiological properties of intra-and extracellular components of the integu ment. Thus its characterization can be best accomplished by a multidisciplinary approach with authors specialized in different fields of science. This multi-author book, in two volumes, provides an up-to date survey of the literature. The first volume deals with the integument of invertebrates, the second with that of vertebrates, both organized primarily on a phylum basis. As the level of knowledge on the integument of phyla differs considerably, the information provided is correspondingly either limited or con densed. For some of the smaller groups of invertebrates little information is available, as often only a few electron micrographs are to be found in the literature; on the other hand, from the large body of knowledge existing for vertebrates, particularly for mammals, no complete overview can be provided, but publica tions giving access to further information have been reviewed critically.

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 β-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.

Mechanics of Biological Systems and Materials represents one of eight volumes of technical papers presented at the Society for Experimental Mechanics Annual Conference & Exposition on Experimental and Applied Mechanics, held at Uncasville, Connecticut, June 13-16, 2011. The full set of proceedings also includes volumes on Dynamic Behavior of Materials, Mechanics of Time-Dependent Materials and Processes in Conventional and Multifunctional Materials, MEMS and Nanotechnology; Optical Measurements, Modeling and, Metrology; Experimental and Applied Mechanics, Thermomechanics and Infra-Red Imaging, and Engineering Applications of Residual Stress.