TAPIRS AND EARLY EOCENE PERISSODACTYLS: A COMPARATIVE ANALYSIS OF FOSSIL DISTRIBUTION AND ENVIRONMENTAL SIMILARITIES

Early Eocene Homogalax, Heptadon, and Hyracotherium are representative of the earliest perissodactyls, and ancient soils (paleosols) in which their remains are found record paleoenvironments that provide clues indicative of their behavior. Homogalax is currently considered a tapir-like stem perissodactyl, and Hyracotherium is widely accepted as the oldest equid. This project seeks to contextualize the development of early perissodactyl behavior through an evolutionary lens by comparing conditions of extinct and extant perissodactyls and their ecology. Paleosol stages of development were used to infer local paleoenvironmental conditions where the fossils were found. Frequency of fossil perissodactyl remains in each paleosol was ascertained from field data in order to identify patterns of distribution. These patterns were evaluated in comparison with the behavior patterns of modern South American tapirs with the aim of situating behavioral development within the realm of environmental and habitat transitions over an evolutionary time frame. Modern South American tapirs regularly travel along their own well-worn networks of trails connecting feeding areas, water sources, and resting spots. Upon arrival, tapirs tend to remain in these destinations for extended periods of time. If this behavior is reflected in the fossil record, it might be expected that higher concentrations of specimens would be found in feeding, watering, and resting places, with a lower frequency of specimens found in transitional/intermediate areas. Initial results suggest that the paleoecology of Homogalax may reflect that of the extant South American tapir patterns of navigational behavior and habitat ranges.