a, b, CT-generated model of skull in oblique dorsolateral view. c, d, Same as a, b, but from a more dorsal perspective, anterior is towards the lower left corner. Light blue, excavations of an air sinus that may be homologous to the inferior vestibule as well as the route by which it connected to the soft tissue nasal passages. Red, premaxillary air sinus. La, lacrimal; Mx, maxilla; Na, nasal; Pa, parietal; pf, postnarial fossa; Px, premaxilla; rb, rostral basin; So, supraoccipital; Sq, squamosal; zy, zygomatic process.