Fig. 6. A left side schematic diagram of the hypothesized muscle action during (A) closing and (B) opening states of the superior (SMM, green) and lateral (LMM, purple) mandibular muscles showing dimensional changes seen in the experimental preparation (lower beak, red; upper beak, blue). The cylindrical lateral mandibular muscle is illustrated in the central diagram with the three fiber orientations: Lat, lateral fibers (red); AP, anterior-posterior fibers (green); DV, dorsal-ventral fibers (blue).