Paper presents the result of study which showed that the Wolf Ranch fauna from the St. David Formation of southeastern Arizona consists of twenty-one taxa, primarily small mammals.
The author describes forty-two fossil taxa recovered during a study of the San Timoteo Badlands that used magnetobiostratigraphy to develop a temporal framework for addressing the tectonic evolution of southern California over the last 6 million years. For the Pliocene, small mammals are an effective means of correlating a magnetostratigraphy to the Geomagnetic Polarity Time Scale when radioisotopic dates are unobtainable.
This book places into modern context the information by which North American mammalian paleontologists recognize, divide, calibrate, and discuss intervals of mammalian evolution known as North American Land Mammal Ages. It incorporates new information on the systematic biology of the fossil record and utilizes the many recent advances in geochronologic methods and their results. The book describes the increasingly highly resolved stratigraphy into which all available temporally significant data and applications are integrated. Extensive temporal coverage includes the Lancian part of the Late Cretaceous, and geographical coverage includes information from Mexico, an integral part of the North American fauna, past and present.
This book is designed as a source and reference for people interested in the history and fossil record of North American tertiary mammals. Each chapter covers a different family or order, and includes information on anatomical features, systematics, the distribution of the genera and species at different fossil localities, and a discussion of their paleobiology. Many of these groups have never been covered in this fashion before.
Two rather different elements combine to explain the origin of this volume: one scientific and one personal. The broader of the two is the scientific basis-the time for such a volume had arrived. Geology had made remarkable progress toward an understanding of the phys ical history of the Caribbean Basin for the last 100 million years or so. On the biological side, many new discoveries had elucidated the distributional history of terrestrial orga nisms in and between the two Americas. Geological and biological data had been combined to yield the timing of important events with unprecedented resolution. Clearly, when each of two broad disciplines is making notable advances and when each provides new insights for the other, the rewards of cross-disciplinary contacts increase exponentially. The present volume represents an attempt to bring together a group of geologists, paleontologists and biologists capable of exploiting this opportunity through presentation of an interdisciplinary synthesis of evidence and hypothesis concerning interamerican connections during the Cretaceous and Cenozoic. Advances in plate tectonics form the basis for a modern synthesis and, in the broadest terms, dictate the framework within which the past and present distributions of organisms must be interpreted. Any scientific dis cipline must seek tests of its conclusions from data outside of its own confines.