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

南美洲猴子进化的模式记录得很少，也很少有人了解。一些人认为，新世界猴（Platyrrhini）从巴塔哥尼亚的1600万至2000万年前的岩石中发现，早于现代家族的起源，也就是说，它们是“干扁头猴”。其他人则认为它们是现代宽鼻科的早期代表。 这两种不同的解释对如何看待阔鼻龙的进化辐射有着深远的影响。早期宽鼻龙的进一步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及其等同物的约1600万年前的岩石中寻找灵长类化石。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，这些地点据说从大西洋沿岸内陆到南纬50-55度的安第斯山脉前线都富含植物。对现有材料的分析和更完整的灵长类动物标本的恢复将提供关于这些早期灵长类动物的生殖和适应的罕见见解。系统发育分析将澄清南美阔鼻猴的多样化模式，并有助于完善现代阔鼻猴家族起源的假设。为了重建各种灭绝物种的适应性特征，来自美国、阿根廷和巴西的科学家团队将研究牙齿、头骨和四肢骨骼的各个方面，以重建每个物种适应性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阔鼻龙进化的环境背景。由阿根廷科学家领导的第二个研究专家小组将研究非灵长类化石的功能解剖学和生态形态学。研究树懒和犰狳的工作已经做了很多。 利用这些已建立的方法作为模型，研究小组将把这项工作扩展到包括啮齿动物、无蹄动物和有袋动物在内的其他主要哺乳动物群体。

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.