Ordinary least squares (OLS) and phylogenetically based regression (PGLS, phylogenetic generalised least squares; OU, Ornstein-Uhlenbeck process) of body mass (kg) against convex hull volume (m3).

AIC, Uncorrected Akaike Information Criterion; d, restricted maximum likelihood estimate of the Ornstein-Uhlenbeck transformation parameter; ±95%, 95% confidence intervals of the intercept and slope; MSE, mean square error of the regression; %PE, mean percentage prediction error of the regression; PE ±95%, 95% confidence interval of mean PE. Log10 transformed OLS regressions discussed throughout the text and are highlighted in bold.