Data from: Early arrival and climatically-linked geographic expansion of New World monkeys from tiny African ancestors

New World monkeys (platyrrhines) are one of the most diverse groups of primates, occupying today a wide range of ecosystems in the American tropics and exhibiting large variations in ecology, morphology, and behavior. Although the relationships among the almost 200 living species are relatively well understood, we lack robust estimates of the timing of origin, ancestral morphology, and geographic range evolution of the clade. Here we integrate paleontological and molecular evidence to assess the evolutionary dynamics of extinct and extant platyrrhines. We develop novel analytical frameworks to infer the evolution of body mass, changes in latitudinal ranges through time, and species diversification rates using a phylogenetic tree of living and fossil taxa. Our results show that platyrrhines originated 5–10 million years earlier than previously assumed, dating back to the Middle Eocene. The estimated ancestral platyrrhine was small – weighing 0.4 kg – and matched the size of their presumed African ancestors. As the three platyrrhine families diverged, we recover a rapid change in body mass range. During the Miocene Climatic Optimum, fossil diversity peaked and platyrrhines reached their widest latitudinal range, expanding as far South as Patagonia, favored by warm and humid climate and the lower elevation of the Andes. Finally, global cooling and aridification after the middle Miocene triggered a geographic contraction of New World monkeys and increased their extinction rates. These results unveil the full evolutionary trajectory of an iconic and ecologically important radiation of monkeys and showcase the necessity of integrating fossil and molecular data for reliably estimating evolutionary rates and trends.

新世界猴（platyrrhines，阔鼻下目）是物种多样性最为丰富的灵长类类群之一，现今栖息于美洲热带地区的各类生态系统中，在生态学、形态学与行为学维度均呈现出显著的多样性。尽管目前学界对近200个现生阔鼻下目物种间的系统发育关系已有相对清晰的认知，但对于该演化支的起源时间、祖先形态以及地理分布演化过程，仍缺乏可靠的定量估算。本研究整合古生物学与分子生物学证据，以解析已灭绝与现生阔鼻下目类群的演化动力学机制。我们构建了全新的分析框架，依托现生与化石类群的系统发育树，对体质量演化、随时间推移的纬度分布范围变化以及物种分化速率开展推演。研究结果表明，阔鼻下目的起源时间较此前的推测提前了500万至1000万年，可追溯至始新世中期。估算得到的阔鼻下目祖先类群体型小巧，体质量约0.4千克，与其推测的非洲祖先体型相吻合。随着三个阔鼻下目科发生分化，我们观测到其体质量范围出现快速变化。在中新世气候适宜期，化石物种多样性达到峰值，阔鼻下目也达到了最广的纬度分布范围；受当时温暖湿润的气候与安第斯山脉较低海拔的条件加持，其分布范围向南延伸至巴塔哥尼亚。中新世中期之后的全球变冷与干旱化事件，最终引发了新世界猴的地理分布收缩，并提升了其灭绝速率。本研究完整揭示了这一兼具标志性与重要生态价值的猴类辐射演化轨迹，同时证实了整合化石与分子数据，方能可靠估算演化速率与演化趋势。