Figure 2.

Turtle shell model. (a) Frontal view of shell (Stigmochelys pardalis) and three-parameter transversal model K (α, R, p, k) of main cross-section. The plastron is approximated by straight line P (equation (2.1)). The carapace is approximated by curve C (equations (2.2)–(2.4)); smooth transition between plastron and carapace achieved by merging function (equation (2.5)). (b) Carapace shape at various values of parameter p. (c) Longitudinal model: schematic side- and top-view contours are circular arcs obtained as averages from measurements; sizes are normalized. (d) Visual comparison of digitized shell image and model surface.