Dissertation Research: The Functional Significance of the Anthropoid Postorbital Septum

本研究的主要目的是阐明 一个叫做眶后隔的解剖结构 这是 形成后部侧面的一片薄骨 的轨道。 很明显这是一个最近进化的结构 这是唯一发现的头盖骨的marticles（高 灵长类动物）和眼镜猴。 虽然眶后隔一直被用作诊断 多年来，在高等灵长类动物的标准中， 事实上，没有对各种假设进行测试， 来解释它的存在。 PI将进行一项 各种各样的实验试图解释这种特性 进化 一种解释是， 用来隔离与咀嚼有关的肌肉 （那些在隔膜后面的）从前面的肌肉是 参与视觉。 这可能对以下方面具有重要意义： 高度视觉导向的动物，如蜥蜴。 的 PI将进行一些动物解剖，包括 下颌骨，以确定各种咀嚼的位置 相对于眼眶的肌肉。 将绘制结果， 作为一种预测工具。 已经提出的另一种解释涉及隔膜， 在咀嚼过程中减少面部的应变。 骨应力的测量可以使用一系列的 已经在耶基斯灵长类中心的动物 这项研究将有助于测试和澄清的力量， 在数百万年前形成了骨隔膜 了解它在今天的动物中的功能。

The primary objective of this research is to clarify the role of an anatomical structure known as the postorbital septum. This is a thin sheet of bone which forms the lateral aspect of the rear of the orbit. It is apparently a recently evolved structure which is only found in the cranium of the anthropoids (the higher primates) and the tarsier. While the postorbital septum has been used as a diagnostic criterion of the higher primates for many years, there have been virtually no tests of the various hypotheses which have been put forward to account for its existence. The PIs will undertake a variety of experiments in an attempt to account for the trait's evolution. One explanation which has been advanced is that the sheet of bone serves to isolate muscles which are involved in mastication (those in back of the septum) from the anterior muscles which are involved in vision. This would presumably be of significance to highly visually-oriented animals such as the anthropoids. The PIs will undertake a number of dissections of animals, including anthropoids, to determine the placement of various masticatory muscles relative to the orbit. Results will be plotted and examined as a predictive tool. Another explanation which has been advanced relates the septum to the reduction of strain in the face during mastication. Measurements of bone stress can be carried out using a series of animals already at the Yerkes Primate Center. This research will help to test and clarify the forces which brought the bony septum into existence millions of years ago and understand its functioning in animals today.