Pliocene to Pleistocene Fauna of Central America: The Isthmus as a Biogeographic Barrier

巴拿马地峡大约在280万到320万年前出现 前 它形成了一个主要的海洋屏障， 热带海洋变成两个截然不同的新领域 海洋环流、盐度、温度和营养物。 它还 连接了两个迄今为止分离的不同陆地动物群 和植物群 它可能是唯一一个最重要的海洋， 在过去的6000万年里气候和地理事件。 这个项目将定位和描述沉积地层 在地峡的两侧， 现在的 利用微观和宏观化石，科茨博士和他的 同事们将测定沉积物的年代， 确定峡部最终闭合的精确时间。 的 项目包括：1）采集和断面测量场 2）大规模样品处理， 标本，3）识别和描述物种，4）分配 时代和古环境的地层和化石，5）进入 所有这些信息都输入到一个专门设计的计算机数据库中。 生成的数据库将具有独特的潜力， 解决生物学中的一些基本问题，例如 和物种起源和灭绝的模式 各种各样的海洋动物和植物，与一个特定的主要 环境事件。

The Isthmus of Panama emerged about 2.8-3.2 million years ago. It formed a major marine barrier splitting the American tropical ocean into two new realms with profoundly different ocean circulation, salinity, temperature and nutrients. It also connected two hitherto separate and different terrestrial faunas and floras. It was perhaps the single most important oceanic, climatic and biogeographic event in the last 60 million years. This project will locate and describe the sedimentary strata on each side of the isthmus dating from about 6 million years to the present. Using micro and macro fossils Dr. Coates and his colleagues will date the sequence of sediments and attempt to establish the precise time of final closure of the isthmus. The project entails 1) collecting and section measuring field expeditions, 2) large-scale sample processing to extract specimens, 3) identifying and describing species, 4) assigning ages and paleoenvironments to the strata and fossils, 5) entering all this information into a specially designed computer database. The database generated will be unique in its potential to address some fundamental questions in biology, such as the causes and patterns of origination and extinction of species in a variety of marine animals and plants, related to a specific major environmental event.