Data_Sheet_1_Out of Africa: A New Afrotheria Lineage Rises From Extinct South American Mammals.docx

The South American native ungulates (SANUs) are usually overlooked in Eutherian phylogenetic studies. In the rare studies where they were included, the diversity of SANUs was underrated, keeping their evolutionary history poorly known. Some authors recognized the SANUs as a monophyletic lineage and formally named it Meridiungulata. Here, we recognized and defined a new supraordinal lineage of Eutheria, the Sudamericungulata, after performing morphological phylogenetic analyses including all lineages of SANUs and Eutheria. The SANUs resulted as non-monophyletic; thus, Meridiungulata is not a natural group; Litopterna and “Didolodontidae” are Panameriungulata and closer to Laurasiatheria than to other “Meridiungulata” (Astrapotheria, Notoungulata, Pyrotheria, and Xenungulata). The other “Meridiungulata” is grouped in the Sudamericungulata, as a new monophyletic lineage of Afrotheria Paenungulata, and shared a common ancestor with Hyracoidea. The divergence between the African and South American lineages is estimated to Early Paleocene, and their interrelationships support the Atlantogea biogeographic model. Shortly afterward, the Sudamericungulata explosively diversified in its four lineages. Confronting the Sudamericungulata evolutionary patterns and the Cenozoic natural events (such as tectonics and climatic and environmental changes, among others) helps to unveil a new chapter in the evolution of Gondwanan Eutheria, as well as the natural history of South America during the Cenozoic.

南美本土有蹄类（South American native ungulates, SANUs）在真兽类系统发育研究中常被忽视。在极少数纳入该类群的相关研究中，其多样性亦被严重低估，导致学界对其演化历史始终未得到充分认知。部分学者曾将SANUs视为单系支系，并将其正式命名为南蹄总目（Meridiungulata）。本研究通过涵盖SANUs与真兽类所有支系的形态学系统发育分析，识别并界定了真兽类的一个全新超目支系——南美有蹄超目（Sudamericungulata）。分析结果显示SANUs并非单系群，因此南蹄总目（Meridiungulata）并非自然类群；滑距骨目（Litopterna）与狄多洛齿科（Didolodontidae）隶属于泛美有蹄类（Panameriungulata），相较于其他‘南蹄总目类群’（闪兽目Astrapotheria、南方有蹄目Notoungulata、焦兽目Pyrotheria与异蹄目Xenungulata），它们与劳亚兽总目（Laurasiatheria）的亲缘关系更为紧密。其余‘南蹄总目类群’则被归入南美有蹄超目（Sudamericungulata），构成非洲兽总目（Afrotheria）近蹄类（Paenungulata）下的一个全新单系支系，并与蹄兔目（Hyracoidea）共享共同祖先。非洲支系与南美支系的分化时间被估算为古新世早期，二者的系统发育关系支持大西洋生物地理模型（Atlantogea biogeographic model）。在此之后，南美有蹄超目迅速在四个支系中实现了爆发式分化。将南美有蹄超目的演化模式与新生代地质事件（如构造运动、气候与环境变化等）相结合开展研究，有助于揭示冈瓦纳真兽类演化的全新篇章，同时也能增进学界对新生代南美洲自然历史的认知。