Squyres Nicole, DeLeon Valerie Burke
Center for Functional Anatomy and Evolution, Johns Hopkins University, 1830 East Monument St., Room 302, Baltimore, MD, 21205.
Department of Anthropology, University of Florida, PO Box 117305, Gainesville, FL, 32611.
Am J Phys Anthropol. 2015 Oct;158(2):257-268. doi: 10.1002/ajpa.22785. Epub 2015 Aug 4.
As a component of the primate shoulder, the clavicle is expected to reflect locomotor adaptations. Whereas previous work has generally focused on clavicular length and torsion, the shape of clavicular curvature may better distinguish taxa and provide additional information about upper limb use in locomotion. This study uses three-dimensional geometric morphometrics to analyze shape differences in the curvatures of the clavicle in different locomotor groups of anthropoid primates.
Sliding semi-landmarks were placed on clavicles of 10 Anthropoid primate species (total n = 85) that display a range of locomotor behaviors. Landmarks (k = 39) were chosen to capture the overall curvature of the clavicle in three dimensions.
The degree of ventral curvature in the clavicle represents a gradient from most-curved in suspensory genera (e.g., Ateles, Hylobates, and Pongo) to least-curved in genera that are rarely suspensory (e.g., Papio and Gorilla). This curvature may allow an increased range of craniodorsal movement without the clavicle impinging on the thoracic outlet. An inferior curvature of the medial clavicle is found in hominoids and brachiators. This curvature could help stabilize the shoulder and prevent superior dislocation of the clavicle in suspension. Finally, a superior curvature in the lateral part of the clavicle, most pronounced in quadrupedal monkeys, may be related to the relative position of the scapula and sternum.
Patterns of clavicular curvature in anthropoid primates reflect locomotor behavior and successfully distinguished among taxonomic and locomotor groups. In the future, this method could be used to assess locomotor behavior in fossil primates. Am J Phys Anthropol 158:257-268, 2015. © 2015 Wiley Periodicals, Inc.
作为灵长类动物肩部的一个组成部分，锁骨有望反映出运动适应性。尽管先前的研究通常集中在锁骨的长度和扭转方面，但锁骨弯曲的形状可能更有助于区分不同的分类群，并提供有关上肢在运动中使用情况的更多信息。本研究采用三维几何形态测量学方法，分析不同运动类群的类人猿灵长类动物锁骨弯曲形状的差异。
在10种类人猿灵长类动物（总数n = 85）的锁骨上放置滑动半地标点，这些动物表现出一系列的运动行为。选择39个地标点来捕捉锁骨在三维空间中的整体弯曲情况。
锁骨腹侧弯曲程度呈现出一个梯度，从最弯曲的悬荡类属（如蛛猴属、长臂猿属和猩猩属）到极少悬荡的类属（如狒狒属和大猩猩属）弯曲程度逐渐降低。这种弯曲可能使颅背侧运动范围增加，而锁骨不会压迫胸廓出口。在类人猿和臂行类动物中发现锁骨内侧有向下弯曲。这种弯曲可能有助于稳定肩部，并防止锁骨在悬荡时向上脱位。最后，锁骨外侧部分的向上弯曲在四足行走的猴子中最为明显，这可能与肩胛骨和胸骨的相对位置有关。
类人猿灵长类动物的锁骨弯曲模式反映了运动行为，并成功地区分了分类群和运动类群。未来，这种方法可用于评估化石灵长类动物的运动行为。《美国体质人类学杂志》2015年第158卷：257 - 268页。© 2015威利期刊公司。
