Late Cenozoic Evolution of North American Bats

蝙蝠是现存哺乳动物的第二大目，也是唯一会飞的哺乳动物。它们也很重要，因为它们的生态作用是多样的，它们对社区结构的贡献可能是巨大的。然而，它们的多样性和相互关系并没有得到很好的理解。反过来，我们对其生物多样性的了解不足阻碍了我们对其保护的努力。人们对蝙蝠之间的关系缺乏了解，部分原因是它们的化石记录不佳。第三纪蝙蝠的化石在北美特别罕见，但在大多数其他大陆也是如此。最近，在佛罗里达州的14个地方收集了数千个小型脊椎动物的化石，这些化石分布在第三纪后半期的大部分地区，从晚渐新世到晚上新世（大约2900万到200万年前）跨越了大约2700万年。这些化石来自于天坑沉积物，其中的蝙蝠标本异常丰富。在一些地方，有数百个标本，使这些地方成为迄今为止在北美第三纪发现的蝙蝠化石最丰富的地方。蝙蝠分属几个不同的科，其中一些在温带的北美已经不存在了。因此，这些化石具有重要的生物地理和古气候意义。该项目的目的是：(1)描述和命名这个大的第三纪蝙蝠化石系列中的新分类群（至少有10个新属和12个新种）；(2)利用计算机辅助分析，通过与博物馆现代蝙蝠标本的比较，确定它们的系统发育关系；(3)记录佛罗里达古动物群第三纪中晚期蝙蝠物种的更替。因为佛罗里达地区保存了整个大陆上记录蝙蝠化石的最好的采样区域和时间段，它们将提供一个初步的模型，通过这个模型，我们可以了解北美第三纪中晚期蝙蝠古动物群的多样化和组成变化。在生物地理学和生物地层学上，它们也可以用于洲际扩散的测试，例如在第三纪晚期在南北美洲和加勒比岛屿之间的其他哺乳动物已经记录的洲际扩散。

9981512Czaplewski & 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.