PCA plots for Type I landmarks and semilandmarks, and associated dominant dorsal endocast shape changes. (a) Principal Component Analysis plot for Type I landmarks; (b) Summary of endocranial shape change along PC1 for Type I landmarks; dorsal endocast contours on deformation grid from average; (c) Principal Component Analysis plot for semilandmarks; (d) Summary of endocranial shape change along PC1 for semilandmarks; dorsal endocast contours on deformation grid from average. Crocodilian specimens are indicated by blue dots, the crocodilian distribution is delimited by a blue hull. Non-maniraptoriform dinosaurs are indicated with orange dots, Maniraptoriformes with yellow dots, Paleognathae with brown dots, and Neognathae with green dots. The avian distribution (Paleognathae + Neognathae) is delimited by a green hull. Endocast shape variations (b,d) include landmark positions as red dots. Coloured hulls (in b) delimit cerebral domains occupied by the telencephalon (orange) and rhombencephalon (yellow).