Department of Anatomy and Anthropology, Sackler Faculty of Medicine, Tel Aviv University, 69978 Tel Aviv, Israel; Institute of Human Origins, Arizona State University, PO Box 874101, Tempe, AZ, 85287, USA.
Institute of Human Origins, Arizona State University, PO Box 874101, Tempe, AZ, 85287, USA; School of Human Evolution and Social Change, Arizona State University, PO Box 872402, Tempe, AZ, 85287, USA.
J Hum Evol. 2021 Feb;151:102913. doi: 10.1016/j.jhevol.2020.102913. Epub 2020 Dec 31.
Although the early hominin species Australopithecus robustus has been known for more than eight decades and is represented by hundreds of fossils from sites in South Africa, a complete, well-preserved skull has been elusive. DNH 7, an adult cranium and mandible from the Drimolen site, was identified, on the basis of its small size, as a presumptive female of A. robustus. Here, we provide a detailed comparative description of the specimen. In cranial, facial, and dental size, DNH 7 is confirmed to lie at the extreme small end of the A. robustus range of variation, along with a few fragmentary maxillofacial specimens from Swartkrans. In addition, relative to the classically derived craniofacial features of the Swartkrans+Kromdraai portions of the A. robustus hypodigm, primitive anatomy pervades the DNH 7 face, braincase, and cranial base. Taken together, these pieces of evidence place DNH 7 in a previously unfilled position on the robust Australopithecus morphocline, where the specimen highlights the morphological distinctions between southern and eastern African species of this group and epitomizes the anatomy expected of the group's last common ancestor.
尽管早期人类物种粗壮南方古猿已经为人所知超过 80 年，并且在南非的多个地点都有数百个化石标本为证，但完整、保存完好的头骨却一直难以寻觅。DNH7 是来自德雷莫伦遗址的一个成年颅骨和下颌骨，由于其尺寸较小，被鉴定为粗壮南方古猿的一个假定雌性个体。在这里，我们提供了对该标本的详细比较描述。在颅骨、面部和牙齿尺寸方面，DNH7 被确认为位于粗壮南方古猿变异范围的极端小端，与来自斯瓦特克朗斯的一些零碎面骨标本一起。此外，相对于粗壮南方古猿形态模式的斯瓦特克朗斯+克罗姆德莱部分的经典衍生颅面特征，DNH7 的面部、脑颅和颅底呈现出原始解剖结构。综合这些证据，DNH7 位于粗壮南方古猿形态渐变线上一个以前未被占据的位置，该标本突出了该群体南部和东部非洲物种之间的形态区别，并概括了该群体最后共同祖先的预期解剖结构。
