Figure 5. Size-normalised tail length and caudal count nodal values reconstructed for amniotes.

Size-normalised amniote nodal values (See Fig. 1; also Materials and Methods): A, tail length, and B, caudal count. Nodes 5–11 are non-avian theropods whereas nodes 12 onwards are birds. Mapping results under EBL and SBL branch length assumptions are labelled as “EBL” and “SBL” respectively. C, tail length and caudal count appear to be proportional (EBL data: y = 0.1233x+0.2553, R² = 0.9697, r = 0.985 which is significant at the 0.01 level (p (2-tailed) = 0.000); SBL data: y = 0.1217x+0.4225, R² = 0.9789, r = 0.989 which is significant at the 0.01 level (p (2-tailed) = 0.000)). Node numbers (1–21) are marked next to each EBL and SBL data point.