Figure 1. Small-bodied mammals that display exceptional longevity. (A) The accepted tree topology for the 15 species included in this study. (B) Maximum longevity residual (left axis, black boxes) and maximum longevity (right axis, grey circles) of the 15 species. Maximum longevity residual (tmax) is the percentage of the expected maximum longevity given adult body size (M), derived from the mammalian allometric equation: tmax = 4.88M0.153 .