Figure 1From: Evolutionary origins of ultrasonic hearing and laryngeal echolocation in bats inferred from morphological analyses of the inner earLog basilar membrane length (mm) versus log body mass0.33(g) plotted across mammals. Circles are sized according to the number of turns in the cochlea, and are colour coded as follows: monotremes (black); marsupials (white); non-whale and non-bat placental mammals (brown); echolocating whales (light grey); non-echolocating whales (dark grey); Yangochiroptera (green); echolocating Yinpterochiroptera (blue); Old World fruit bats (orange). The regression line (ordinary least squares) for placental mammals excluding all bats and whales (log basilar membrane = 0.498 log body mass0.33 + 0.717, n = 25, R2 = 0.907, F = 225.343, P = 2.25 x 10 -13) is shown by the solid line and the 95% prediction intervals for this placental mammal sub-sample is represented by the dashed line. This is similar to the regression results for all non-echolocating mammals (with baleen whales and Old World fruit bats omitted): log basilar membrane = 0.503 log body mass0.33 + 0.664, (n = 29, R2 = 0.702, F = 63.877, P = 1.37 x 10 -8).Back to article page