Fig. 9
From: Occipital condyle width (OCW) is a highly accurate predictor of body mass in therian mammals
Linear regression between log OCW and log body mass under OLS (in red), PGLS under a Brownian model (in blue), PGLS under a Brownian model excluding monotremes (in green), and PGLS under an OU model (in purple, dashed to not obscure the other lines), showing how the inclusion of monotreme taxa greatly biases the PGLS regression line under a Brownian model due to the deep divergence between Theria and Monotremata