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. 2009 Dec 15;212(24):4040–4055. doi: 10.1242/jeb.029983

Table 4.

Relative sarcomere length ranges in mammalian jaw muscles during various activities

Animal Muscle Relative sarcomere length range (%)1 Behavior
Pig2 Anterior superficial masseter 92-117 Range of active muscle
Anterior temporalis 88-118 contraction during chewing
Middle temporalis 93-117
Rabbit3 Superficial masseter 92-116 Range of active muscle
Temporalis 88-110 contraction during chewing
Rat4 Anterior masseter 78-126 Range of manipulated jaw
Temporalis 74-95 opening during experiment
Marmoset5 Anterior superficial masseter 80-120 Gouging (10-55 deg. gape)
Anterior temporalis 73-103
Middle temporalis 71-102
Anterior superficial masseter 68-101 Chewing (0-30 deg. gape)6
Anterior temporalis 66-85
Middle temporalis 66-83
Tamarin5 Anterior superficial masseter 79-141 Wide opening (10-55 deg. gape)7
Anterior temporalis 85-145
Middle temporalis 85-143
Anterior superficial masseter 63-109 Chewing (0-30 deg. gape)7
Anterior temporalis 74-110
Middle temporalis 74-110
1

Relative sarcomere length ranges were calculated following Burkholder and Lieber (Burkholder and Lieber, 2001).

2

Data from Herring et al. (Herring et al., 1984). We used an estimated optimal sarcomere length of 2.4 μm following Herring et al. (Herring et al., 1984).

3

Data from Weijs and van der Wielen-Drent (Weijs and van der Wielen-Drent, 1982; Weijs and van der Wielen-Drent, 1983). We used an optimal sarcomere length of 2.41 μm based on thin filament length estimate of 1.16 μm from rabbit psoas muscle (Ringkob et al., 2004).

4

Data from Nordstrom et al. (Nordstrom et al., 1974). We used an estimated optimal sarcomere length of 2.4 μm following Burkholder and Lieber (Burkholder and Lieber, 2001). Range of jaw opening does not appear to have a physiological basis.

5

Data from this study (Tables 2 and 3).

6

Range of chewing gape taken from Vinyard et al. (Vinyard et al., 2009).

7

Estimated gapes are taken from marmoset behaviors and do not necessarily reflect gapes routinely used by tamarins. This chewing gape range is probably a reasonable estimate for this species.