Paleontological Investigations to Recover Fossil Monkeys from the Middle Cenozoic of South America

【摘要】南美洲猴子的进化模式文献记载甚少，人们对其了解甚少。一些人认为，从巴塔哥尼亚1600万至2000万年前的岩石中发现的新世界猴（Platyrrhini）比现代家族的起源要早，也就是说，它们是“干Platyrrhini”。另一些人则认为它们是现代羊颈龙家族的早期代表。这两种不同的解释对如何看待斜颈水龙的进化辐射具有深远的影响。进一步的早期斜颈龙化石材料将有助于解决这一争论。一个由美国和阿根廷古生物学家组成的联合小组将在阿根廷巴塔哥尼亚的圣克鲁斯组和类似组1600万年前的岩石中寻找灵长类动物化石。收集工作将集中在已证实的地点，并将收集工作扩大到其他鲜为人知的地点，据称从大西洋沿岸内陆到南纬50-55度的安第斯山脉前线，那里有丰富的化石。对现有材料的分析和更完整的灵长类动物标本的恢复将为这些早期类人猿灵长类动物的系统发育和适应提供难得的见解。系统发育分析将阐明南美白颈猴的多样化模式，并有助于完善关于现代白颈猴家族起源的假设。为了重建各种灭绝物种的适应情况，来自美国、阿根廷和巴西的科学家团队将研究牙齿、头骨和肢骨的各个方面，以重建每个物种适应和生活史的重要细节。野外小组收集的其他动物遗骸将填补早期长颈犀牛进化的环境背景。由阿根廷科学家领导的第二组研究专家将研究非灵长类动物化石的功能解剖学和生态形态学。对树懒和犰狳的研究已经开展了很多工作。以这些已建立的方法为模型，研究小组将把这项工作扩展到其他主要的哺乳动物群体，包括啮齿动物、非有蹄类动物和有袋动物。

AbstractThe pattern of monkey evolution in South America is poorly documented and little understood. Some argue that New World monkeys (Platyrrhini) known from 16-20 million year old rocks of Patagonia predate the origins of the modern families, that is, they are 'stem platyrrhines'. Others argue that they are early representatives of the modern platyrrhine families. The two alternative interpretations have profound implications for how the evolutionary radiation of platyrrhines is viewed. Further fossil material of early platyrrhines will contribute to resolving this debate. A joint team of US and Argentine paleontologists will search for fossil primates in ~16 million-year-old rocks of the Santa Cruz Formation and its equivalents in Patagonian Argentina. Collecting will concentrate on proven localities and expand collecting efforts to other lesser-known sites said to be richly fossiliferous from the Atlantic coast inland to the Andean front at 50-55 degrees South latitude. Analysis of the existing materials and recovery of even more complete specimens of primates will offer a rare insight about the phylogeny and adaptations of these early anthropoid primates. A phylogenetic analysis will clarify the pattern of diversification of South American platyrrhine monkeys and help to refine hypotheses about the origins of the modern platyrrhines families. To reconstruct adaptive profile of the various extinct species, a team of scientists from the US, Argentina and Brazil will study various aspects of the teeth, skulls and limb bones to reconstruct important details of the each species' adaptation and life history. Collections of other faunal remains by the field group will fill out the environmental context in which early platyrrhines evolved. A second team of research specialists headed by the Argentine scientists will study the functional anatomy and ecomorphology of non-primate fossils. Much work already has been undertaken to study the sloths and armadillos. Using these established approaches as a model, the research group will extend this work to encompass other major mammal groups including rodents, notoungulates, and marsupials.