Fig. 8. Stiffness (MPa) of mineralized (yellow) (approximately 50% mineral by dry mass) and demineralized vertebrae (blue) (<15% mineral by dry mass) at various strain rates (% s^–1). Mineralized vertebrae are stiffer than demineralized vertebrae (P<0.001). Stiffness does not vary significantly with strain rate in mineralized vertebrae (P=0.818). However, demineralized vertebrae had significantly lower stiffness values at 1% and 5% strain than they did at 10% and 20% strain (F_3,30=10.693; P<0.001). Letters above the box and whisker plot denote significant differences.