Dietary ecology and its relationship with both muscle architecture and bite force potential has been studied in many mammalian (and non‐mammalian) taxa. However, despite the diversity of dietary niches that characterizes the superfamily Musteloidea, the masticatory muscle fiber architecture of its members has yet to be investigated anatomically. In this study, we present myological data from the jaw adductors in combination with biomechanical data derived from craniomandibular measurements for 17 species representing all four families (Ailuridae, Mephitidae, Mustelidae, and Procyonidae) of Musteloid. These data are combined to calculate bite force potential at each of three bite points along the dental row. Across our sample as a whole, masticatory muscle mass scaled with isometry or slight positive allometry against both body mass and skull size (measured via a cranial geometric mean). Total jaw adductor physiological cross‐sectional area scaled with positive allometry against both body mass and skull size, while weighted fiber length scaled with negative allometry. From a dietary perspective, fiber length is strongly correlated with dietary size such that taxa that exploit larger foods demonstrated myological adaptations toward gape maximization. However, no consistent relationship between bite force potential and dietary mechanical resistance was observed. These trends confirm previous findings observed within the carnivoran family Felidae (as well as within primates), suggesting that the mechanisms by which masticatory anatomy adapts to dietary ecology may be more universally consistent than previously recognized. Anat Rec, 302:2287–2299, 2019. © 2019 American Association for Anatomy
Carnivorans represent extreme ecomorphological diversity, encompassing remarkable variation in form, habitat, and diet. The relationship between the masticatory musculature and dietary ecology has been explored in a number of carnivoran lineages, including felids and the superfamily Musteloidea. In this study, we present novel architectural data on two additional carnivoran families—Ursidae and Canidae—and supplement these previous studies with additional felid, musteloid, herpestid, hyaenid, and viverrid taxa (a total of 53 species across 10 families). Gross dissection data were collected following a standardized protocol—sharp dissection followed by chemical digestion. Summed jaw adductor forces were also transformed into bite force estimates (BF) using osteologically calculated leverages. All data were linearized, log‐transformed, and size‐adjusted using two proxies for each taxon—body mass (BM) and cranial geometric mean—to assess relative scaling trends. These architectural data were then analyzed in the context of dietary ecology to examine the impact of dietary size (DS) and dietary mechanical properties (DMP). Muscle mass, physiological cross‐sectional area, and BF scaled with isometry or positive allometry in all cases, whereas fascicle lengths (FLs) scaled with isometry or negative allometry. With respect to diet, BM‐adjusted FLs were strongly correlated with DS in musteloids, but not in any other lineage. The relationship between size‐adjusted BF and DMP was also significant within musteloids, and across the sample as a whole, but not within other individual lineages. This interfamilial trend may reflect the increased morphological and dietary diversity of musteloids relative to other carnivoran groups.
more » « less- PAR ID:
- 10448413
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- The Anatomical Record
- Volume:
- 305
- Issue:
- 2
- ISSN:
- 1932-8486
- Page Range / eLocation ID:
- p. 477-497
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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