Department of Anthropology, Dartmouth College, Hanover, NH 03755, USA.
Department of Anthropology, Boston University, Boston, MA 02215, USA.
Sci Adv. 2018 Jul 4;4(7):eaar7723. doi: 10.1126/sciadv.aar7723. eCollection 2018 Jul.
The functional and evolutionary implications of primitive retentions in early hominin feet have been under debate since the discovery of . Ontogeny can provide insight into adult phenotypes, but juvenile early hominin foot fossils are exceptionally rare. We analyze a nearly complete, 3.32-million-year-old juvenile foot of (DIK-1-1f). We show that juvenile individuals already had many of the bipedal features found in adult specimens. However, they also had medial cuneiform traits associated with increased hallucal mobility and a more gracile calcaneal tuber, which is unexpected on the basis of known adult morphologies. Selection for traits functionally associated with juvenile pedal grasping may provide a new perspective on their retention in the more terrestrial adult .
自早期人类足部原始保留的功能和进化意义被发现以来，一直存在争议。个体发生可以提供对成体表型的深入了解，但幼年早期人类足部化石非常罕见。我们分析了一个近乎完整的、332 万年前的幼年 （DIK-1-1f）的足部化石。我们表明，幼年个体已经具有在成年标本中发现的许多两足特征。然而，它们也具有与增加的第一跖骨活动性和更纤细的跟骨结节相关的内侧楔骨特征，这与已知的成年形态不符。对与幼年足部抓握功能相关的特征的选择，可能为它们在更具陆地性的成年形态中的保留提供了一个新的视角。
