Johnson S E, Shapiro L J
Department of Anthropology, University of Texas at Austin, 78712-1086, USA.
Am J Phys Anthropol. 1998 Mar;105(3):333-54. doi: 10.1002/(SICI)1096-8644(199803)105:3<333::AID-AJPA4>3.0.CO;2-S.
Atelines are of particular interest to primate evolutionary studies because they converge with hominoids in postcranial anatomy, including the vertebral column. Currently, our understanding of ateline vertebral morphology is limited to mainly qualitative descriptions and functional interpretations based on general categories of positional behavior. Even less is known about the vertebrae of other platyrrhines. This study more closely examines vertebral form and function in atelines and cebines by combining direct field observations of axial postures and movements, assessments of spinal loading regimes, and a detailed vertebral morphometric analysis. Field observations (Corcovado, Costa Rica) on Ateles geoffroyi, Alouatta palliata, Cebus capucinus, and Saimiri oerstedii were quantified in conjunction with a morphometric analysis of ateline and cebine lumbar vertebrae. Hylobates was also included for comparison. Compared to Cebus and Saimiri, atelines engage more frequently in postures and locomotor behaviors that induce pronounced bending loads on the spine. All atelines share lumbar adaptations for resisting bending, including ventrodorsally elongated vertebral bodies and perpendicularly oriented transverse processes. Among atelines, lumbar region lengths and vertebral bodies are shortest in Ateles and Brachyteles, longest in Alouatta (resembling Cebus), and intermediate in Lagothrix. Compared to Cebus and all atelines, Saimiri has a relatively longer lumbar region, longer and less ventrodorsally expanded vertebral bodies, and more ventrally oriented transverse processes. These features accentuate bending loads, but increase the sagittal flexibility required for leaping. Vertebral convergence between hylobatids and atelines is more readily interpretable as a product of shared spinal loading patterns than shared positional behaviors.
蜘蛛猴科对于灵长类动物进化研究具有特殊意义，因为它们在颅后解剖结构，包括脊柱方面，与类人猿趋同。目前，我们对蜘蛛猴科椎体形态的了解主要局限于基于一般姿势行为类别的定性描述和功能解读。对于其他阔鼻猴类的椎体了解更少。本研究通过结合对轴向姿势和运动的直接野外观察、脊柱负荷状态评估以及详细的椎体形态测量分析，更深入地研究了蜘蛛猴科和僧面猴科的椎体形态与功能。对 Geoffroy蜘蛛猴、长毛吼猴、白喉卷尾猴和奥氏松鼠猴在哥斯达黎加科科瓦多的野外观察进行了量化，并结合对蜘蛛猴科和僧面猴科腰椎的形态测量分析。还纳入了长臂猿进行比较。与卷尾猴和松鼠猴相比，蜘蛛猴科更频繁地采取会在脊柱上产生明显弯曲负荷的姿势和运动行为。所有蜘蛛猴科都有适应抵抗弯曲的腰椎特征，包括腹背向拉长的椎体和垂直定向的横突。在蜘蛛猴科中，Ateles属和Brachyteles属的腰椎区域长度和椎体最短，长毛吼猴属最长（类似于卷尾猴），绒毛蛛猴属居中。与卷尾猴和所有蜘蛛猴科相比，松鼠猴的腰椎区域相对较长，椎体更长且腹背向扩展程度较小，横突更偏向腹侧。这些特征加剧了弯曲负荷，但增加了跳跃所需的矢状面灵活性。长臂猿科和蜘蛛猴科之间的椎体趋同更容易被解释为共同脊柱负荷模式的产物，而非共同姿势行为的产物。
