Table 2.
Correlations for independent contrasts of orientation angles and skull length
| Convergence angle |
Frontation angle |
||||
|---|---|---|---|---|---|
| Clade | n | r | P | r | P |
| Extant taxa only | |||||
| Carnivora | 38 | 0.506 | 0.001 | –0.189 | 0.263 |
| Caniformia | 22 | 0.138 | 0.541 | –0.236 | 0.290 |
| Arctoidea | 17 | 0.261 | 0.311 | –0.403 | 0.110 |
| Feliformia | 16 | 0.546 | 0.035 | –0.188 | 0.501 |
| All taxa | |||||
| Carnivora | 68 | 0.057 | 0.649 | 0.108 | 0.389 |
| Caniformia | 43 | –0.122 | 0.437 | 0.296 | 0.057 |
| Crown-clade Caniformia * | 40 | –0.126 | 0.439 | 0.306 | 0.058 |
| Canidae | 21 | 0.132 | 0.569 | 0.380 | 0.099 |
| Arctoidea | 19 | –0.116 | 0.636 | –0.039 | 0.900 |
| Feliformia | 25 | 0.151 | 0.480 | 0.013 | 0.951 |
| Felidae | 7 | –0.783 | 0.065 | 0.031 | 0.544 |
| Viverridae, Hyaenidae, ‘Herpestidae’† | 11 | 0.541 | 0.085 | –0.131 | 0.701 |
| ‘Herpestidae’† | 6 | 0.728 | 0.101 | –0.152 | 0.773 |
Crown-clade Caniformia excludes the Amphicyonidae and is identical to ‘Caniformia’ in the extant-only analysis.
‘Herpestidae’ includes true mongooses and Malagasy carnivorans, as previous analyses include some or all of these taxa in Herpestidae.
In contrast to skull length, no significant correlations exist between encephalization and orbit orientation among extant taxa. When fossil and extant taxa are included in the analysis, no relationships exist between encephalization and either orientation angle, arguing against Carnivora-wide structural relationships between orbit orientation and encephalization (Fig. 3). However, we do observe several significant correlations for analyses among carnivoran subclades when fossil and living taxa are analysed. FA is positively correlated with encephalization for Felidae (Noble et al. 2000) (Table 3), although in our data set this is due to the cheetah (Acinonyx jubatus), which stands out as an outlier (Fig. 4). Excluding the cheetah removes the significance (r = 0.320, P = 0.588); therefore this correlation must be viewed with caution until a larger sample is examined.
n, number of taxa; r, Pearson correlation coefficient; P, two-tailed significance. Significant correlations are highlighted in bold. Extant-only analyses are made for a smaller number of taxonomic groups, as sample size precluded finer partitioning.