Williams Scott A, Wang Xue, Avilez Monica V, Fok Lillian, Giraldo Maria V, Spear Jeffrey K, Prang Thomas C
Center for the Study of Human Origins, Department of Anthropology, New York University, New York, NY 10003, USA; New York Consortium in Evolutionary Primatology, New York, NY 10024, USA.
Center for the Study of Human Origins, Department of Anthropology, New York University, New York, NY 10003, USA; New York Consortium in Evolutionary Primatology, New York, NY 10024, USA.
J Hum Evol. 2025 Apr;201:103650. doi: 10.1016/j.jhevol.2025.103650. Epub 2025 Feb 24.
Miocene apes represent snapshots in time of key transitions in hominoid evolution. While all extant apes are adapted to orthograde posture and suspensory behavior, many Miocene apes demonstrate evidence for pronogrady and habitual arboreal quadrupedalism or present 'mosaic' morphologies suggestive of locomotion and posture unlike any extant catarrhine. Here, we use three-dimensional geometric morphometrics to study penultimate lumbar vertebrae of extant anthropoids and those of three well-preserved Miocene apes: Ekembo nyanzae (KNM-MW 13142), Morotopithecus bishopi (UMP 67-28), and Pierolapithecus catalaunicus (IPS 21350-64), which have been interpreted as a pronograde arboreal quadruped, an orthograde suspensory or vertical climbing ape, and an orthograde vertical climber that was not adapted to suspensory behavior, respectively. Our results show that E. nyanzae shares three-dimensional shape space with terrestrial papionins, whereas M. bishopi and P. catalaunicus fall within overlapping morphospace shared by Ateles and hylobatids. Morotopithecus bishopi and P. catalaunicus share with hylobatids and brachiating atelids (Ateles and Brachyteles) well-established features such as dorsal lumbar transverse (costal) processes and a newly identified feature in this study, the presence of a convex pillar along the pars interarticularis that forms the lateral borders of the laminae. The latter feature is also shared with E. nyanzae. Together with their large body size estimates, we interpret these results to indicate that E. nyanzae was primarily a pronograde quadruped that may have been semiterrestrial rather than strictly arboreal, while M. bishopi and P. catalaunicus were adapted to both orthogrady and forelimb-dominated climbing and suspension.
中新世猿类代表了类人猿进化关键转变时期的时间快照。虽然所有现存猿类都适应直立姿势和悬荡行为，但许多中新世猿类显示出俯伏姿势和习惯性树栖四足行走的证据，或者呈现出“镶嵌”形态，暗示其运动和姿势与任何现存狭鼻猿不同。在这里，我们使用三维几何形态测量学来研究现存灵长类动物以及三种保存完好的中新世猿类的倒数第二腰椎：恩氏埃肯博猿（KNM-MW 13142）、毕氏莫罗托猿（UMP 67-28）和卡氏皮尔劳尔猿（IPS 21350-64），它们分别被解释为俯伏树栖四足动物、直立悬荡或垂直攀爬猿以及不适应悬荡行为的直立垂直攀爬者。我们的结果表明，恩氏埃肯博猿与陆生狒狒类共享三维形状空间，而毕氏莫罗托猿和卡氏皮尔劳尔猿则落在蜘蛛猴属和长臂猿科共享的重叠形态空间内。毕氏莫罗托猿和卡氏皮尔劳尔猿与长臂猿科以及善于臂行的蜘蛛猴属（蜘蛛猴属和短尾蛛猴属）共享一些既定特征，如腰椎背侧横突（肋骨突），以及本研究新发现的一个特征，即沿关节间部有一个凸柱，形成椎板的外侧边界。后一个特征也为恩氏埃肯博猿所共有。结合它们较大的体型估计，我们将这些结果解释为表明恩氏埃肯博猿主要是俯伏四足动物可能是半陆生而非严格树栖，而毕氏莫罗托猿和卡氏皮尔劳尔猿则既适应直立姿势又适应以 forelimb 为主导的攀爬和悬荡。 （注：原文中“forelimb”有误，推测可能是想说“forelimb-dominated”，翻译时已按此修正）
