Evaluating bony predictors of bite force across the order Carnivora

Area of Science:

• Paleontology
• Biomechanics
• Comparative Anatomy

Background:

• Bite force in carnivorans is vital for ecological understanding.
• Osteological proxies are used to estimate jaw muscle size and force, especially for extinct species.
• Existing methods include volumetric approximations and attachment site measurements.

Purpose of the Study:

• To compare three cranial osteological techniques for estimating jaw adductor muscle size.
• To assess the accuracy of 2D-photographic and 3D-surface data approaches against dissection-derived muscle weights and physiological cross-sectional area (PCSA).

Main Methods:

• Compared 2D-photographic and 3D-surface data methods for estimating muscle size.
• Utilized dissection-derived muscle weights and PCSA as benchmarks.
• Analyzed 40 carnivoran taxa across diverse families, body sizes, and diets.

Main Results:

• 3D-surface approaches yielded more accurate muscle size estimates than 2D-lateral photographs.
• Muscle cross-sectional area estimates correlated better with muscle mass and PCSA than attachment area estimates.
• Muscle thickness is critical; larger muscles do not proportionally increase attachment site area.

Conclusions:

• 3D osteological methods are superior for estimating carnivoran jaw muscle size.
• Accounting for muscle thickness is essential for accurate bite force estimations.
• Caution is advised when applying single osteological methods across diverse carnivoran phylogenies.