Burrows Anne M, Smith Timothy D
Department of Physical Therapy, Duquesne University, Pittsburgh, Pennsylvania 15282, USA.
Anat Rec A Discov Mol Cell Evol Biol. 2003 Sep;274(1):827-36. doi: 10.1002/ar.a.10093.
Gross and histologic aspects of facial expression muscles are presented here for Otolemur spp. (suborder Prosimii, family Lorisidae) and are compared with those of lemuroids. Muscles of facial expression are involved in social signaling among primates, and are a primary means by which close-proximity nonverbal communication is achieved. These muscles have been well described in catarrhines and many of the lemuroids; however, their arrangement is not well known in the lorisids. In the present study we examined muscles of facial expression in Otolemur by dissecting preserved faces. The arrangement and appearance of the muscles were noted, and samples were gathered from each muscle for histologic processing. The results showed 17 muscles of facial expression in Otolemur, as compared to seven reported in previous studies. Histologically, muscles of the ear region were arranged in tight, dense fascicles, while muscles of the orbital region were arranged more loosely. Grossly, the facial expression muscles in Otolemur were very similar in morphology and attachments to those in the lemuroids, with some differences in the ear region. Otolemur garnettii had several muscles that appeared to be more robust than in the larger O. crassicaudatus. This may be due to dietary and/or social differences between the species. In previous studies it was concluded that, relative to lemuroids, Otolemur has a primitive arrangement of facial expression muscles. The current results do not support that conclusion, and in fact support a far greater similarity between Otolemur and lemuroids in general. These results underscore the need for a reexamination of facial musculature in prosimians in general, and may have taxonomic value as regards the position of Otolemur with lemuroids and other galagos.
本文展示了眼镜猴属（原猴亚目，懒猴科）面部表情肌的大体和组织学特征，并与狐猴类进行了比较。面部表情肌参与灵长类动物之间的社交信号传递，是近距离非语言交流的主要方式。这些肌肉在狭鼻猴类和许多狐猴类中已有详细描述；然而，它们在懒猴科中的排列情况尚不清楚。在本研究中，我们通过解剖保存的面部来检查眼镜猴的面部表情肌。记录了肌肉的排列和外观，并从每块肌肉中采集样本进行组织学处理。结果显示，眼镜猴有17块面部表情肌，而先前研究报道为7块。在组织学上，耳部区域的肌肉排列紧密、密集，而眼眶区域的肌肉排列则较为松散。在大体上，眼镜猴的面部表情肌在形态和附着方面与狐猴类非常相似，只是在耳部区域存在一些差异。加氏眼镜猴的几块肌肉似乎比体型较大的粗尾眼镜猴更粗壮。这可能是由于物种之间的饮食和/或社会差异所致。在先前的研究中得出结论，相对于狐猴类，眼镜猴的面部表情肌排列原始。目前的结果并不支持这一结论，实际上总体上支持眼镜猴与狐猴类之间有更大的相似性。这些结果强调了一般需要重新审视原猴亚目的面部肌肉组织，并且可能在眼镜猴与狐猴类及其他婴猴的分类地位方面具有分类学价值。
