Table 2.
Whole‐sample and species regressions of proposed ecomorphological variables against snout shape (RW1 score). Individuals with 2.1 ≤ log(CS) ≤ 2.4 were used for the analyses
| Variable by snout shape (RW1 score) | n | R 2 | P | Slope | Intercept | Pagel's λ |
|---|---|---|---|---|---|---|
| Whole‐sample analysis with ordinary least squares (OLS) regression | ||||||
| CV of maxillary alveolus diameter | 111 | 0.668 | < 0.001 | −0.242 | 0.151 | NA |
| Maxillary tooth spacing | 111 | 0.860 | < 0.001 | −0.676 | 0.593 | NA |
| Relative STF area [(STF area)1/2/CS] | 123 | 0.315 | < 0.001 | 0.069 | 0.134 | NA |
| Relative PFD (PFD/CS) | 120 | 0.376 | < 0.001 | −0.247 | 0.564 | NA |
| Relative basioccipital tubera width (BTW/CS) | 122 | 0.009 | 0.311 | 0.015 | 0.184 | NA |
| Relative symphysis length (SL/CS) | 110 | 0.667 | < 0.001 | 2.233 | 0.567 | NA |
| Species analysis with phylogenetic generalized least squares (PGLS) regression | ||||||
| CV of maxillary alveolus diameter | 10 | 0.863 | < 0.001 | −0.232 | 0.155 | 0.000 |
| Maxillary tooth spacing | 10 | 0.972 | < 0.001 | −0.646 | 0.591 | 0.000 |
| Mode maxillary tooth count | 10 | 0.054 | 0.519 | 3.154 | 16.352 | 1.000 |
| Relative STF area [(STF area)1/2/CS] | 10 | 0.509 | 0.021 | 0.098 | 0.137 | 0.000 |
| Relative PFD (PFD/CS) | 10 | 0.634 | 0.006 | −0.237 | 0.541 | 1.000 |
| Relative basioccipital tubera width (BTW/CS) | 10 | 0.130 | 0.306 | 0.053 | 0.187 | 0.000 |
| Relative symphysis length (SL/CS) | 10 | 0.676 | 0.004 | 1.476 | 0.835 | 1.000 |
CS, centroid size; CV, coefficient of variation; PFD, pterygoid flange depth; STF, supratemporal fenestra. Mean species RW1 scores and mean variable values were used for species analysis (PGLS regression). The molecular tree of Oaks (2011) was used for PGLS regression.