DeLeon Valerie B, Smith Timothy D, Rosenberger Alfred L
Department of Anthropology, University of Florida, Gainesville, Florida, USA.
School of Physical Therapy, Slippery Rock University, Slippery Rock, Pennsylvania, USA.
Anat Rec (Hoboken). 2016 Dec;299(12):1631-1645. doi: 10.1002/ar.23476.
Bony structure of the postorbital region is a key trait distinguishing major clades of primates. Strepsirrhines share a postorbital bar, and anthropoids share a complete postorbital septum. At issue is whether the partial postorbital septum of tarsiers unites living tarsiers more closely with anthropoids than with certain large-eyed Eocene fossils. Previously we reported incomplete postorbital closure in tarsiers at birth. In this article, we document comparative analyses of the postorbital region in a broad range of perinatal primates. Virtual reconstructions of microCT data were used to study three-dimensional structure of the perinatal cranium in these taxa. We also describe and illustrate formation of the tarsier partial postorbital septum through the perinatal period using a growth series of Tarsius syrichta. Our results support the hypothesis that partial postorbital septation in the tarsier is secondary to eye hypertrophy. Based on these observations, we propose a structural hypothesis for phylogenetic differences observed in the primate postorbital region. Specifically, we propose that key postorbital traits, including the frontal spur in strepsirrhines and the posterior lamina of the zygomatic in anthropoids, develop as a result of the spatial relationships of brain, eyes, and teeth. Haplorhines are united by expansion of the anterior cranial fossa and loss of the frontal spur. Anthropoids are further united to the exclusion of tarsiers by expansion of the temporal lobes and associated formation of the posterior lamina of the zygomatic. Mechanical forces related to these spatial relationships may be modulated by deep fascia of the orbit to induce formation of the postorbital septum. Anat Rec, 299:1631-1645, 2016. © 2016 Wiley Periodicals, Inc.
眶后区域的骨骼结构是区分灵长类主要分支的关键特征。原猴亚目动物具有眶后棒，而类人猿具有完整的眶后隔。问题在于，跗猴的部分眶后隔是否使现存跗猴与类人猿的关系比与某些大眼睛始新世化石的关系更为密切。此前我们报道了跗猴出生时眶后闭合不完全的情况。在本文中，我们记录了对广泛的围产期灵长类动物眶后区域的比较分析。利用微型计算机断层扫描（microCT）数据的虚拟重建来研究这些分类群围产期颅骨的三维结构。我们还使用菲律宾眼镜猴的生长序列描述并说明了跗猴部分眶后隔在围产期的形成过程。我们的结果支持这样的假说，即跗猴的部分眶后隔形成是眼睛肥大的继发结果。基于这些观察结果，我们提出了一个关于在灵长类眶后区域观察到的系统发育差异的结构假说。具体而言，我们提出关键的眶后特征，包括原猴亚目动物的额突和类人猿的颧骨后板，是由脑、眼和牙齿的空间关系所导致的。简鼻亚目动物通过前颅窝的扩大和额突的消失而联系在一起。类人猿通过颞叶的扩大以及相关的颧骨后板的形成而进一步联系在一起，从而将跗猴排除在外。与这些空间关系相关的机械力可能受眼眶深筋膜调节，从而诱导眶后隔的形成。《解剖学记录》，299:1631 - 1645，2016年。©2016威利期刊公司。
