The Microstructure of Dinosaur Bone: Deciphering Biology with Fine-scale Techniques. Anusuya Chinsamy-Turan. Johns Hopkins University Press, Baltimore, 2005. 195 pp., illus. $85.00 (ISBN 080188120X cloth).
One hundred years ago, Adolf Seitz began the microscopic study of dinosaur bone. Thirty years ago, Armand de Ricqlès posited that bone microstructure was a clear indicator of the thermal biology and physiology of dinosaurs. He added fuel to the fire of the debate over hot-blooded versus cold-blooded dinosaurs by concluding that the histological characteristics of dinosaur bone indicated high rates of metabolism, high rates of sustained growth, intensive bone–body fluid exchange, and endothermy.
Data available now, however, indicate that this is an overly simplistic view. Anusuya Chinsamy-Turan, a professor of zoology and a fellow of the University of Cape Town, South Africa, presents recent findings on the histology of dinosaur bone, and assesses what bone microstructure can and cannot explain about the biology of dinosaurs and Mesozoic birds. In this well-written, well-edited volume, she concludes that bone microstructure does indicate how bone formed during growth, and it does provide information on how factors such as seasonality, ontogenetic age, and lifestyle adaptations affected its growth, but she also finds that speculations about physiology based on bone histology are just that: speculations.
Chinsamy-Turan's analysis of the relationship between fibrolamellar bone and high vascularity brings together a vast array of data from many reptilian taxa, both extant and extinct. The author shows that fibrolamellar bone is not restricted to nonavian dinosaurs, mammals, and birds, but is widespread among the Reptilia and among animals that have long been considered ectotherms, such as Permian dicynodonts and gorgonopsians (nonmammalian synapsids). The correlation between fibrolamellar bone and high metabolism is not supported by the data. She does the same careful review of the data on Haversian bone, zonal bone, growth rings in basal birds, growth plates of dinosaurs, dinosaur lungs and ventilation, nasal turbinates, and oxygen isotopes, and concludes that although the data do not support proposals that dinosaurs were endothermic, they do indicate that dinosaurs were active and dynamic animals in the Mesozoic world.
Chinsamy-Turan has done the scientific community a great service by pulling together the wealth of information about dinosaur bone microstructure, and interpreting that information clearly and logically. Starting with a clear explanation of the organization of bone tissue on a microstructural level and the changes in bone composition during fossilization, she moves on to a helpful overview of dinosaur phylogeny and an insightful explanation of modern approaches to the study of dinosaur bones. Detailed descriptions of bone biology and beautiful color plates of dinosaur bone histology make dinosaur osteology accessible to any biologist who is fascinated with the biology of dinosaurs, as well as to both professors and graduate students working in this field. This portion of the book will be especially useful to anyone preparing a lecture on dinosaur biology for a class in general biology, vertebrate zoology, or herpetology. The book does contain a few errors in biochemistry, such as the confusion of DNA and proteins (p. 18) and uncertainty about the use of polymerase chain reaction (p. 39), but these do not detract from the overall excellence of the book.
There is a wealth of information about the biology of all vertebrates hidden in the bones of living and extinct animals. The classical approach of histology is often overlooked in today's modern molecular biology laboratories, but The Microstructure of Dinosaur Bone makes clear that this approach is a vibrant and essential tool in developing a good understanding of the evolution of animals with backbones. What is needed now are more studies of extant animals so that researchers can better understand how the relationships between the ecology, physical environment, and physiology of vertebrates such as reptiles are reflected in the histology of their bones. There may be much more variation in bone physiological processes—the remodeling of bone structure and the formation of growth rings, fibrolamellar bone, and Haversian bone, among others—than researchers have discovered to date. Detailed studies of the bones of reptiles across their ranges could provide fascinating insights into how this tissue grows in response to differences in the physical and biotic environments.
Following her detailed treatment of dinosaur bone biology, Chinsamy-Turan delights the reader with a treatise on how dinosaurs grew and the biology of early birds. The final chapter on dinosaur physiology evidences an enthusiasm for the subject that is contagious. This chapter, like many other parts of the book, can be readily understood by that high school student whose excitement over dinosaurs takes her to the museum to look at skeletons. The Microstructure of Dinosaur Bone will help make the rest of high school life bearable while this future paleontologist looks forward to unearthing her own fossils.
Chinsamy-Turan's accessible, engaging book contains enough personal reflections and professional opinions to keep readers enthralled. It brings dinosaur biology to life and puts a face on the normally mundane world of bone histology. The clarity of The Microstructure of Dinosaur Bone, and the obvious enthusiasm with which it was written, ensure that it will widely read by those interested in paleontology, whatever their level of learning.
