Figure 8
Skull modularity of caenophidian snakes. In caenophidians, the palatomaxillary arches (in italicized boldface) and prefrontals consistently form left and right modules, almost always distinct from all other skull elements (see main text for minor exceptions). (a–f) Representative pattern of caenophidian skull modularity, illustrated using Thamnophis radix (UAMZ R636) in (a) dorsal, (b) ventral, (c) left lateral, and (d) right lateral views of the skull, and (e) left lateral and (f) right lateral views of the mandible. (g) Network dendrogram of Thamnophis, reflecting this network structure. Q-modules are indicated by Qmax (represented by the red dotted line). S-modules are indicated by black (p < 0.001), grey (0.001 ≤ p < 0.01), or white (0.01 ≤ p < 0.05) circles. (h) Network representation of the skull of Thamnophis (see Supplementary Fig. S58 for labelled version). ecp ectopterygoid, mx maxilla, pal palatine, pt pterygoid. Dendrogram and network generated in R [v.4.0.3]122 and RStudio [v.1.3.1093]123 (see “Methods” section); specimen visualized in Dragonfly [v.4.1]114.
