Premium
The functional correlates of jaw‐muscle fiber architecture in primates
Author(s) -
Taylor Andrea B.,
Vinyard Christopher J.
Publication year - 2010
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.24.1_supplement.178.8
Subject(s) - biology , anatomy , skull , callitrichidae , fiber , callithrix , primate , muscle fibre , zoology , skeletal muscle , ecology , chemistry , organic chemistry
The jaw muscles are responsible for generating jaw forces and movements yet surprisingly little is known about the architecture of these muscles in primates. To better understand the relationship among jaw‐muscle fiber architecture, feeding behavior, and diet, we evaluated and compared masseter and temporalis fiber architecture in marmosets ( Callithrix jacchus , Cebuella pygmaea ), tamarins ( Saguinus oedipus ), capuchins ( Cebus sp), and large‐bodied hominoids. Muscles were removed en masse from the skull, weighed, and whole muscle and fiber lengths measured. We computed pinnation angles and physiologic cross‐sectional areas (PCSAs). In some cases, fiber architecture differences can be predictably linked to functional and adaptive differences in feeding behavior. Thus, the relatively longer, less pinnate‐fibered muscles in tree‐gouging marmosets compared to nongouging tamarins can be functionally linked to the production of relatively wide jaw gapes during tree gouging. Likewise, C. apella displays relatively larger PCSAs compared to other capuchins, consistent with their occasional exploitation of exceptionally resistant foods. Fiber architecture, however, fails to predict differences in feeding behavior and diet among hominoids. We discuss the implications for reconstructing feeding behavior and diet in extinct taxa. Grant sponsor: NSF; Grant numbers: BCS‐0452160, BCS‐0094666, BCS‐0412153; Grant sponsor: NIH; Grant number: R24 HD050837; Grant sponsor: Duke Undergraduate Research Support and the Biology Research Forum of Trinity College.