Figure 1. The ability of the mandibular adductors to generate torque about the temporomandibular joint (TMJ) was estimated at ten regularly spaced intervals of the M. temporalis (T1–T10); at five regularly spaced intervals of the M. masseter profunda + M. zygomaticomandibularis (M1–M5); and the anterior-most insertion of the M. masseter superficialis. A, lion (Panthera leo; CN3503; ♂), with mandible at occlusion and at estimated maximal gape, illustrating torque about the TMJ at T1 (green vectors); B, Smilodon fatalis [LACMHC2001-173 (cranium) and LACMHC2001-4543 (mandible)] with mandible at occlusion and at estimated maximal gape, illustrating torque about the TMJ at M2 (blue vectors), and at SM (red vectors). Abbreviations: Im, inlever moment arm for masseter muscle fibre torque about the TMJ; I, inlever moment arm for temporalis muscle fibre torque about the TMJ; O, outlever moment arm to the carnassial (P4) t c paracone apex; O, outlever moment arm to the centre of C1; T, effective (rotational) torque about the TMJ; T, theoretical ca e f force output from the muscle fibre; Q, angle between Te and Tf. Scale bars = 10 cm.

Published as part of Christiansen, Per, 2011, A dynamic model for the evolution of sabrecat predatory bite mechanics, pp. 220-242 in Zoological Journal of the Linnean Society 162 (1) on page 224, DOI: 10.1111/j.1096-3642.2010.00675.x, http://zenodo.org/record/5440205