Richard H. Madden – författare

Gran Barranca in Patagonia exposes the most complete sequence of middle Cenozoic paleofaunas in South America. It is the only continuous continental fossil record of the Southern Hemisphere between 42 and 18 million years ago, when climates at high latitudes transitioned from warm humid to cold dry conditions. This volume presents the geochronology of the fossil mammal sequence and a compilation of the latest studies of the stratigraphy, sedimentology, mammals, plants, invertebrates and trace fossils. It is also the first detailed treatment of the vertebrate faunal sequence at Gran Barranca, providing important new evidence about biotic diversity and evolution in the native species. A revised taxonomy allows a reevaluation of the origination and extinction of herbivorous mammals, marsupials, and xenarthrans, and the earliest occurrence of rodents and primates in southern latitudes. Academic researchers and advanced students in vertebrate paleontology, geochronology, sedimentology and paleoprimatology will value this wealth of new information.

The evolution of high-crowned teeth, hypsodonty, is a defining characteristic of many terrestrial herbivores. To date, the most prominent focus in the study of the teeth of grazing herbivores has been co-evolution with grasses and grasslands. This book develops the idea further and looks at the myriad ways that soil can enter the diet. Madden then expands this analysis to examine the earth surface processes that mobilize sediment in the environment. The text delivers a global perspective on tooth wear and soil erosion, with examples from the islands of New Zealand to the South American Andes, highlighting how similar geological processes worldwide result in convergent evolution. The final chapter includes a review of elodonty in the fossil record and its environmental consequences. Offering new insights into geomorphology and adaptive and evolutionary morphology, this text will be of value to any researcher interested in the evolution of tooth size and shape.