This comprehensive systematic revision of the Bridge Creek flora is based on large collections of megafossil specimens from the John Day and Crooked River basins. The flora was found to be more diverse than previously recognized, with at least 125 species. At least 11 genera are extinct, but the majority are extant members of deciduous forests. The flora was derived from a variety of sources and represents a classic example of the broadleaved deciduous forests that became widespread at mid-latitudes following the Eocene-Oligocene climatic cooling.
The plant fossil record indicates that the genus Metasequoia was widely distributed throughout the Northern Hemisphere from the early Late Cretaceous to the Plio-Pleistocene. Today the genus has shrunk to one species with approximately 5,000 mature individuals in southeastern China’s Xiahoe Valley. This book distills the current understanding of the biology, ecology and physiology of fossil and living Metasequoia, current research directions and problems that remain unresolved.
This flora of 70 species is dominated by deciduous trees, many with descendants in China. Precipitation was 890 mm, mean annual temperature 12.5°C, the annual range 10°C, and freezing rare. Elevation was about 1000 meters. Comparison with the Horse Prairie flora, 30 miles east and across the present continental divide, indicates that the divide was then low and discontinuous, with warmer climate to the east.
An Eocene (45 Ma) flora from Thunder Mountain caldera shows that montane conifer forest species from upper slopes descended to interfinger with mixed conifer-deciduous hardwood forest on the caldera floor then near 1700 m. Most species are allied to those in the western United States, but a few genera are in China. Precipitation was near 100 cm yearly, with most in summer.
The marine Eocene-Oligocene transition of 34 million years ago was a critical turning point in Earth's climatic history, when the warm, high-diversity "greenhouse" world of the early Eocene ceded to the glacial, "icehouse" conditions of the early Oligocene. This book surveys the advances in stratigraphic and paleontological research and isotopic analysis made since 1989 in regard to marine deposits around the world. In particular, it summarizes the high-resolution details of the so-called doubthouse interval (roughly 45 to 34 million years ago), which is critical to testing climatic and evolutionary hypotheses about the Eocene deterioration. The authors' goals are to discuss the latest information concerning climatic and oceanographic change associated with this transition and to examine geographic and taxonomic patterns in biotic turnover that provide clues about where, when, and how fast these environmental changes happened. They address a range of topics, including the tectonic and paleogeographic setting of the Paleogene; specific issues related to the stratigraphy of shelf deposits; advances in recognizing and correlating boundary sections; trends in the expression of climate change; and patterns of faunal and floral turnover. In the process, they produce a valuable synthesis of patterns of change by latitude and environment.
Among the fishes. a remarkably wide range ofbiological adaptations to diverse habitats has evolved. As weIl as living in the conventional habitats of lakes. ponds. rivers. rock pools and the open sea. fish have solved the problems of life in deserts. in the deep sea. in the cold Antarctic. and in warm waters of high alkalinity or of low oxygen. Along with these adaptations. we find the most impressive specializations of morphology. physiology and behaviour. For example we can marvel at the high-speed swimming of the marlins. sailfish and warm-blooded tunas. air breathing in catfish and lungfish. parental care in the mouth-brooding cichlids and viviparity in many sharks and toothcarps. Moreover. fish are of considerable importance of the survival of the human species in the form ofnutritious and delicious food ofnumerous kinds. Rational exploitation and management of our global stocks of fishes must rely upon a detailed and precise insight of their biology. The Chapman and Hall Fish and Fisheries Series aims to present timely volumes reviewing important aspects of fish biology. Most volumes will be of interest to research workers in biology. zoology. ecology and physiology. but an additional aim is for the books to be accessible to a wide spectrum of non specialist readers ranging from undergraduates and postgraduates to those with an interest in industrial and commercial aspects of fish and fisheries.
