Methodology and Material
The 12 common chimpanzees (Pan troglodytes) dissected for this study were made available by the following institutions: George Washington University (GWUANT PT1 and GWUANT PT2, adult females, formalin embalmed), Howard University (HU PT1, infant male, formalin embalmed), Duquesne University (Yerkes Regional Primate Center, uncatalogued adult male, formalin embalmed), Valladolid University (VU PT1, 81 kilograms, adult male, fresh, provided by the Fundacion Mona; VU PT2, 72 kilograms, adult male, fresh, provided by Zoo-Aquarium of Madrid; VU PT3, 58 kilograms, adult female, fresh, provided by the Bioparc Fuengirola), and Primate Foundation of Arizona (PFA 1016, 50-years old adult female, fresh; PFA 1009, adult female, fresh; PFA 1051, 1-year old infant female, fresh; PFA 1077, infant female, fresh; PFA UNC-uncatalogued-infant male, fresh). We took photographs of the musculoskeletal system of all of the specimens we dissected, but the muscle weights listed in this atlas are from the VU PT1 specimen (total body weight = 81 kg) that was in particularly good condition. The photographs of the osteological structures shown in this atlas are from the VU PT3 specimen. In the text below, when the data are available, we provide for each muscle: 1) its weight in the VU PT1 specimen. The total mass of all the striated muscles is given in parentheses immediately following the name of the muscle. In the case of paired muscles, the muscles of the left and right sides are referred to as LSB and RSB, respectively. When the muscle is part of a symmetrical structure (e.g., stylohyoideus), the weight given is that of the muscle of one side of the body; when the muscle is unpaired (e.g., diaphragm), the weight given is that of the part of the muscle that comes from one side only; 2) the most common attachments and innervation of the muscle within the chimpanzee clade, based on our dissections and on our literature review; 3) the function of the muscle (e.g., based on electromyographic studies-EMG-of neck and upper limb muscles or the use of the Facial Action Coding System-FACS-for facial muscles); 4) comparative notes, especially when where there are differences (e.g., regarding the presence/ absence of the muscle, or of its bundles, its attachments, and/or its innervation) between the configuration usually found in chimpanzeess and the configuration
found in a specimen dissected by us (in these cases we often provide photographs to illustrate the differences) or by others; and 5) a list of the synonyms that have been used by other authors to designate that muscle.