This volume brings together information about recent discoveries and current theories concerning the origin and early evolution of anthropoid primates monkeys, apes, and humans. Although Anthropoidea is one of the most dis tinctive groups of living primates, and the origin of the group is a frequent topic of discussion in the anthropological and paleontological literature, the topic of anthropoid origins has rarely been the foeus of direct discussion in primate evolution. Rather, diseussion of anthropoid origins appears as a ma jor side issue in volumes dealing with the origin of platyrrhines (Ciochon and Chiarelli, 1980), in discussions about the phylogenetic position of Tarsius, in descriptions of early anthropoid fossils, and in descriptions and revisions of various fossil prosimians. As a result, the literature on anthropoid origins has a long history of argument by advocacy, in which scholars with different views have expounded individual theories based on a small bit of evidence at hand, often with little consideration of alternative views and other types of evidence that have been used in their support. This type of scholarship struck us as a relatively unproductive approach to a critical issue in primate evolution.

The study ofanthropoid origins continues to be a lightning rod for research in paleoanthropology. Issuessurrounding anthropoid origins impact the higher leveltaxonomy ofprimates, adaptivescenariosfor basalprimate radiations, and the timing of origination of the major primate clades. Basic questions about anthropoid evolution remain unanswered. Where do anthropoids fit phyloge- netically among primates? Where and when did the group originate? What functional and adaptive innovations characterize anthropoids today and what is the adaptive significanceand phylogenetic history ofthese innovations? The fossil record of early anthropoid evolution has greatly improved in recent years. Developments in systematictechniques and theory, as well as the burgeoning molecular evidence, make this an ideal time for these fossil discoveries to be placed in the context of data on the relationships among living primates. There isan improved understandingoffunction and adaptation in the visual system, brain, and masticatory apparatus, key anatomical systems where anthropoid synapomorphies are concentrated. New methods for estimating visualacuity and activitypatterns in fossil primates are providing insights into the evolution ofthe visualsystem. The rapid accumulation ofinformation on color vision in primates, including new genetic evidence of possible trichro- macyin strepsirrhines, and new behavioraldata on the benefitsofcolor vision, makes this an exciting time to evaluate the role of chromatic perception in anthropoid evolution. Research into the primate visualsystem by neuroscien- tists has generated a plethoraofimportant data in recent years, making this an ideal time to bring these researchers together with anthropologists.

This volume brings together information about recent discoveries and current theories concerning the origin and early evolution of anthropoid primates monkeys, apes, and humans. Although Anthropoidea is one of the most dis tinctive groups of living primates, and the origin of the group is a frequent topic of discussion in the anthropological and paleontological literature, the topic of anthropoid origins has rarely been the foeus of direct discussion in primate evolution. Rather, diseussion of anthropoid origins appears as a ma jor side issue in volumes dealing with the origin of platyrrhines (Ciochon and Chiarelli, 1980), in discussions about the phylogenetic position of Tarsius, in descriptions of early anthropoid fossils, and in descriptions and revisions of various fossil prosimians. As a result, the literature on anthropoid origins has a long history of argument by advocacy, in which scholars with different views have expounded individual theories based on a small bit of evidence at hand, often with little consideration of alternative views and other types of evidence that have been used in their support. This type of scholarship struck us as a relatively unproductive approach to a critical issue in primate evolution."

This volume brings together a series of papers that address the topic of reconstructing behavior in the primate fossil record. The literature devoted to reconstructing behavior in extinct species is ovelWhelming and very diverse. Sometimes, it seems as though behavioral reconstruction is done as an afterthought in the discussion section of papers, relegated to the status of informed speculation. But recent years have seen an explosion in studies of adaptation, functional anatomy, comparative sociobiology, and development. Powerful new comparative methods are now available on the internet. At the same time, we face a rapidly growing fossil record that offers more and more information on the morphology and paleoenvironments of extinct species. Consequently, inferences of behavior in extinct species have become better grounded in comparative studies of living species and are becoming increas ingly rigorous. We offer here a series of papers that review broad issues related to reconstructing various aspects of behavior from very different types of evi dence. We hope that in so doing, the reader will gain a perspective on the various types of evidence that can be brought to bear on reconstructing behavior, the strengths and weaknesses of different approaches, and, perhaps, new approaches to the topic. We define behavior as broadly as we can including life-history traits, locomotion, diet, and social behavior, giving the authors considerable freedom in choosing what, exactly, they wish to explore."

This volume brings together a series of papers that address the topic of reconstructing behavior in the primate fossil record. The literature devoted to reconstructing behavior in extinct species is ovelWhelming and very diverse. Sometimes, it seems as though behavioral reconstruction is done as an afterthought in the discussion section of papers, relegated to the status of informed speculation. But recent years have seen an explosion in studies of adaptation, functional anatomy, comparative sociobiology, and development. Powerful new comparative methods are now available on the internet. At the same time, we face a rapidly growing fossil record that offers more and more information on the morphology and paleoenvironments of extinct species. Consequently, inferences of behavior in extinct species have become better grounded in comparative studies of living species and are becoming increas ingly rigorous. We offer here a series of papers that review broad issues related to reconstructing various aspects of behavior from very different types of evi dence. We hope that in so doing, the reader will gain a perspective on the various types of evidence that can be brought to bear on reconstructing behavior, the strengths and weaknesses of different approaches, and, perhaps, new approaches to the topic. We define behavior as broadly as we can including life-history traits, locomotion, diet, and social behavior, giving the authors considerable freedom in choosing what, exactly, they wish to explore."

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.

Coastal exposures of the Santa Cruz Formation in southern Patagonia have been a fertile ground for recovery of Early Miocene vertebrates for more than 100 years. This volume presents a comprehensive compilation of important mammalian groups which continue to thrive today. It includes the most recent fossil finds as well as important new interpretations based on ten years of fieldwork by the authors. A key focus is placed on the paleoclimate and paleoenvironment during the time of deposition in the Middle Miocene Climatic Optimum (MMCO) between twenty and fifteen million years ago. The authors present the first reconstruction of what climatic conditions were like and present important new evidence of the geochronological age, habits and community structures of fossil bird and mammal species. Academic researchers and graduate students in paleontology, paleobiology, paleoecology, stratigraphy, climatology and geochronology will find this a valuable source of information about this fascinating geological formation.

Coastal exposures of the Santa Cruz Formation in southern Patagonia have been a fertile ground for recovery of Early Miocene vertebrates for more than 100 years. This volume presents a comprehensive compilation of important mammalian groups which continue to thrive today. It includes the most recent fossil finds as well as important new interpretations based on ten years of fieldwork by the authors. A key focus is placed on the paleoclimate and paleoenvironment during the time of deposition in the Middle Miocene Climatic Optimum (MMCO) between twenty and fifteen million years ago. The authors present the first reconstruction of what climatic conditions were like and present important new evidence of the geochronological age, habits and community structures of fossil bird and mammal species. Academic researchers and graduate students in paleontology, paleobiology, paleoecology, stratigraphy, climatology and geochronology will find this a valuable source of information about this fascinating geological formation.