Late Cenozoic Evolution of North American Bats

University Of Oklahoma Norman Campus, Norman OK

Investigators

Abstract

9981512 Czaplewski & Morgan Bats comprise the second largest order of living mammals and the only mammals that fly. They are also important because their ecological roles are diverse and their contributions to community structure can be substantial. Yet their diversity and relationships are not well understood. In turn, our poor understanding of their biodiversity hinders our efforts at their conservation. The lack of understanding of the relationships of bats is partly due to their poor fossil record. Fossils of bats of Tertiary age are particularly rare in North America, but also in most other continents. Recently, thousands of fossils of small vertebrates have been collected from a series of 14 localities in Florida distributed across most of the latter half of the Tertiary period, spanning approximately 27 million years of time from late Oligocene to late Pliocene (about 29 million to 2 million years ago). The fossils originate from sinkhole deposits and are unusually rich in specimens of bats. In a few of the sites, hundreds of specimens are available, making these by far the richest localities for fossil bats ever found in the Tertiary in North America. The bats belong to several different families, some of which no longer occur in temperate North America. The fossils thus have important biogeographic and paleoclimatic implications. The aims of this project are: (1) to describe and name new taxa (at least 10 new genera and 12 new species are present) in this large series of Tertiary bat fossils; (2) to determine their phylogenetic relationships by comparison with museum specimens of modern bats using computer-assisted analyses, (3) to document bat species turnover during the middle-to-late Tertiary period in the Florida paleofaunas. Because the Florida localities preserve the best-sampled area and time period recording fossil bats in the entire continent, they will provide an initial model by which we may understand the diversification and changes in composition of bat paleofaunas during the middle-late Tertiary in North America. Biogeographically and biostratigraphically, they may also lend themselves to tests of intercontinental dispersals such as that already documented by other mammals in the late Tertiary between North and South America and the Caribbean islands.