Collaborative Research: RUI: Chronology and Ecology of Late Pleistocene Megafauna at Rancho La Brea

合作研究：RUI：拉布雷亚牧场晚更新世巨型动物的年代学和生态学

• 批准号: 1758108
• 负责人: Julie Meachen
• 金额: $ 3.16万
• 依托单位: Des Moines University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-04-01 至 2024-02-29
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1758108&HistoricalAwards=false
• 关键词: Collaborative; Research; RUI; Chronology; Ecology

The Rancho La Brea tar pits of Los Angeles, California contain thousands of bones from large mammals --dire wolves, sabertooth cats, coyotes, extinct bison, horses, and others-- trapped in sticky surface oil deposits during the last Ice Age. This unparalleled fossil assemblage allows rigorous studies of extinct mammal biology, especially of carnivores which are rare at most fossil sites. The La Brea fossils span a critical time in Earth's history (approximately 50,000 years ago to the present) that includes major events such as the end of the last Ice Age, the arrival of humans in North America, and an extinction that killed two thirds of the large mammals on the continent. This unique deposit will be used to investigate relationships between major environmental changes and evolutionary variation (size, diet, etc.) in large mammals, information that is critical for promoting the survival of wildlife today. The project involves significant community outreach in the greater Los Angeles area through the Tar Pits Museum and will create educational content that will be available online for high school teachers across the country. The major impediment to system-level study at Rancho La Brea is a paucity of radiocarbon dates and the resulting inability to correlate biotic change with time. This project will intensively radiocarbon date samples from multiple pits spanning the last 50,000 years to establish the first detailed chronology for the entrapment of four extinct species of large mammals, and one extant species. It will involve the collection and compilation of census data for these species to track changes in total abundance and diversity, as well as data on morphological and dietary changes. A well-resolved chronology will allow these data on evolutionary changes in mammals and the Pleistocene megafaunal extinctions to be linked to existing records of major paleo-environmental changes. This work will have broad implications for our understanding of extinctions, survival, environmental variables, and humans on mammalian ecology, which is directly relevant to modern conservation.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

加利福尼亚州洛杉矶的兰乔拉布莱亚沥青坑包含数千块大型哺乳动物的骨骼--恐狼、剑齿猫、郊狼、灭绝的野牛、马和其他动物--在上一个冰河时代被困在粘稠的表层石油沉积物中。这种无与伦比的化石组合使得对灭绝的哺乳动物生物学，特别是对食肉动物的严格研究成为可能，而食肉动物在大多数化石遗址都是罕见的。拉布雷亚化石跨越了地球历史上的一个关键时期(大约5万年前到现在)，其中包括一些重大事件，如最后一个冰河时代的结束，人类在北美的到来，以及导致该大陆三分之二大型哺乳动物死亡的灭绝。这种独特的沉积物将被用来研究主要环境变化和进化变异(体型、饮食等)之间的关系。在大型哺乳动物中，对促进当今野生动物生存至关重要的信息。该项目通过焦油坑博物馆在大洛杉矶地区进行了重要的社区推广，并将创建教育内容，供全国各地的高中教师在线使用。在牧场拉布雷亚进行系统水平研究的主要障碍是缺乏放射性碳测年，因此无法将生物变化与时间联系起来。该项目将对过去50,000年来多个坑的放射性碳样品进行密集测年，以建立首次详细的捕获四种已灭绝大型哺乳动物和一种现存物种的年表。它将涉及收集和汇编这些物种的普查数据，以跟踪总丰度和多样性的变化，以及形态和饮食变化的数据。一个分辨率良好的年表将使这些关于哺乳动物进化变化和更新世大型动物灭绝的数据与现有的主要古环境变化记录联系起来。这项工作将对我们理解灭绝、生存、环境变量和人类对哺乳动物生态的影响产生广泛的影响，这与现代保护直接相关。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Pre–Younger Dryas megafaunal extirpation at Rancho La Brea linked to fire-driven state shift

• DOI: 10.1126/science.abo3594
• 发表时间: 2023-08
• 期刊: Science
• 影响因子: 56.9
• 作者: F. O’Keefe;R. Dunn;Elic M. Weitzel;M. Waters;Lisandro Martínez;W. Binder;J. Southon;J. Cohen