Connecting the chondrocranium: Biomechanics of the suspensorium in reptiles

A toolbox for the retrodeformation and muscle reconstruction of fossil specimens in Blender

“…However, in contrast to the approach of Thomason [ 17 ], the cross section is usually calculated by dividing the three-dimensional volume of the muscle by its length, rather than choosing one area to measure cross-sectional area. To obtain muscle volumes for force calculations, studies have approximated muscle volumes as frustums (partial cones) spanning between the origin and attachment area [ 22 , 23 ]. Another method is to use modified NURBS (non-uniform rational B-splines) circles (essentially designating the shape of several sections along the muscle) and bridging between these, which requires the user to know the positions and shapes of specific cross sections along the muscle [ 24 ].…”

“…Note that in the Dickinson study, origin and insertions were compared separately, whereas the frustum approach (e.g. Sellers et al [ 22 ], Wilken et al [ 23 ], Cost et al [ 19 ]) takes into account both origin and attachment areas, as well as muscle length. Bates et al [ 31 ] compared the Thomason [ 17 ] dry skull method and an approach based on attachment areas and found that for both methods, muscle properties, bite force, bone stress and stress patterns were less accurate compared to data and models obtained from cadaver data.…”