Fig. 7. Relationship between maximum running speed (MRS) and body mass for fossorial (filled circles) and semi-fossorial (open circles) mammals. Solid line is the phylogenetically correct regression relating MRS to mass for fossorial species (equation: MRS=1.27M ^0.21±0.04_b, where the mass exponent is mean ± s.e.). Inner dotted lines represent the 95% confidence interval of this regression; outer broken lines represent the 95% prediction interval. Data sources are provided in Materials and methods.