Continued Paleoanthropological Research in the Laetoli area, Tanzania

过去50年的古生物学研究已经证明了东非遗址对于记录人类进化的最早阶段的重要性。坦桑尼亚的Laetoli是其中最重要的遗址之一。Laetoli先前的研究已经导致化石发现，对提高对人类进化史的理解做出了重大贡献。该遗址至关重要，原因如下：(1)它是早期人类南方古猿阿法种（Australopithecus afarensis）最大的藏品之一，对了解其解剖学、古生物学和系统发育状况非常重要。脚印化石的重大发现为记录两足动物的起源提供了重要的证据。(3)在350 - 380万年前的Laetolil上地层中发现的古人类样本，在东非地区的代表性较差，因此对早期古人类谱系的变异、时间趋势和进化变化的讨论具有重要意义。(4)在Laetolil下层（3.8 Ma ~ 4.3 Ma以上）和Ndolanya上层（2.6 ~ 2.7 Ma）也发现了化石，这表明Laetoli可能有助于更广泛地了解2.5 ~ 5.0 Ma之间的人科动物进化。(5) Laetoli的动物种类繁多，可以作为与非洲其他遗址比较的年代久远的参考。(6) Laetoli古人类的古生态背景为上新世-更新世古人类的生境偏好和生态变化提供了重要信息。该项目的目的是继续在Laetoli进行长期的地质和古生物学调查。主要目标是恢复更多的原始人类化石，并获得关于古生物学、地质学和古生态学的进一步信息。具体目标是：(1)进行系统的地面收集；(2)寻找有生产价值的新的古生物产点；（三）深入开展地质调查，进一步了解地层学和地质历史；(4)获得进一步的放射性测年，以更严格地限定含化石地层的年龄；(5)更精确地重建古生态；(6)更好地记录动植物的分类学、进化关系和古生物学；(7)恢复更多的古人类化石，以提高我们对其解剖学、古生物学和系统发育的理解。科学价值：这些调查结果将用于解决古人类学的几个关键问题：(1)更好地了解阿法南猿和埃塞俄比亚副猿的解剖学、古生物学和系统发育关系；(2)对莱托里古人类的古生态关联进行了更为详细和严谨的评价；(3)更全面的地质学、地质年代学和古生物学知识。更广泛的影响：在Laetoli的持续研究和探索提供了产生关键新数据的潜力，这些数据将对更好地理解人类进化的化石证据做出重大贡献。此外，该项目还为研究生在野外方法、地质学和脊椎动物古生物学方面的培训提供了重要的机会。该计划的国际范围还提供了与坦桑尼亚和其他外国科学家和机构的合作教育和研究联系。

Paleontological research over the past fifty years has demonstrated the significance of sites in East Africa for documenting the earliest stages of human evolution. Laetoli in Tanzania is renowned as one of the most important of these sites. Previous research at Laetoli has led to fossil finds that have contributed significantly to an improved understanding of the evolutionary history of humans. The site is critically important for several reasons: (1) it has yielded one of the largest collections of the early hominid Australopithecus afarensis, and is important for understanding its anatomy, paleobiology and phylogenetic status. (2) The remarkable discovery of fossilized footprints provides crucial evidence for documenting the origins of bipedalism. (3) The hominid-bearing Upper Laetolil Beds, dated at 3.5-3.8 Ma (million years ago), sample a time period that is generally poorly represented in East Africa, and are therefore critical in discussions of variation, temporal trends and evolutionary change in early hominid lineages. (4) Fossils have also been recovered from the Lower Laetolil Beds (3.8 Ma to older than 4.3 Ma) and the Upper Ndolanya Beds (2.6-2.7 Ma), which suggests that Laetoli has the potential to contribute to a broader understanding of hominid evolution between 2.5-5.0 Ma. (5) Laetoli has a diverse fauna that serves as a well-dated reference for comparisons with other sites in Africa. (6) The paleoecological context of the hominids at Laetoli provides important information on hominid habitat preferences and on ecological changes during the Plio-Pleistocene.The aim of the project is to continue with long-term geological and paleontological investigations at Laetoli. The main objectives are to recover additional fossil hominids and to obtain further information on the paleontology, geology, and paleoecology. The specific goals are: (1) to conduct systematic surface collections; (2) to prospect for productive new paleontological occurrences; (3) to conduct further geological investigations, in order to gain a better understanding of the stratigraphy and geological history; (4) to obtain further radiometric dates to more narrowly constrain the ages of the fossil-bearing horizons; (5) to more accurately reconstruct the paleoecology; (6) to better document the taxonomy, evolutionary relationships, and paleobiology of the fauna and flora; and (7) to recover additional fossil hominids to improve our understanding of their anatomy, paleobiology and phylogeny.Scientific merits: Results from these investigations will be used to address several key issues in paleoanthropology: (1) a better appreciation of the anatomy, paleobiology and phylogenetic relationships of Australopithecus afarensis and Paranthropus aethiopicus; (2) a more detailed and critical assessment of the paleoecological associations of the Laetoli hominids; and (3) a more comprehensive knowledge of the geology, geochronology, and paleontology. Broader impacts: Continued research and exploration at Laetoli offers the potential to yield critical new data that will contribute significantly to a better understanding of the fossil evidence for human evolution. In addition, the project provides an important opportunity for graduate student training in field methods, geology and vertebrate paleontology. The international scope of the program also provides collaborative educational and research links with Tanzanian and other foreign scientists and institutions.