Dissertation Research: Evaluating Habitat Change and its Influence on the Decline of Middle Eocene primate Communities in North America

Washington University, Saint Louis MO

Investigators

Abstract

The North American Eocene primates have been the subjects of numerous scholarly studies regarding their adaptive diversity and phylogenetic relationships. However, these primates show a distinctive pattern of community evolution during the Eocene epoch. During the early Eocene intervals, morphological diversity and species richness increased rapidly and by the middle Eocene, primate diversity was at its peak. Yet, during the latter half of the middle Eocene, species numbers began to decrease, it seems, quite rapidly. This decline of primate diversity in North America has been attributed to changes in climate and habitat. While these hypotheses of climate and habitat change have been put forth, they have never been rigorously tested. The purpose of this research is to explore the factors that led to the decline in primate diversity during the later intervals of the middle Eocene. Specifically, the researchers will evaluate the effects of habitat change on the decline of primate species during the latter intervals of the middle Eocene using a case study of North American western interior fossil localities. The researchers will combine methods of habitat reconstruction with the assessment of changing primate community structure in order to investigate how local habitats have influenced the decline of primate communities in the western interior during the middle Eocene. Analyses of North American Middle Eocene mammalian faunas and extant Neotropical mammalian faunas will be used to determine: 1) the habitat characterizations for middle Eocene western interior localities using ecological diversity analysis, 2) the structure of mammalian communities containing primates from the middle Eocene, in terms of these functional variables: diet, body size and locomotion (or substrate preference), and 3) the ecomorphological variation over time in primate and co-occurring arboreal mammal communities in relationship to the habitats in which they are found.