Didelphis marsupialis, du baa 0164, bone isosurfaces derived from CT scans. Cranium in A, dorsal and D, ventral views. Premaxillae in B, dorsal, C, anterior, and E, ventral views. F, premaxillae and vomer (anterior part) in anterior view. Scale for A and D is 25 mm; scale for B–C and E-F is 10 mm. Abbreviations: ap, alveolar process; b, body, fp, facial process; I1, upper first incisor; ii, incisive incisure; lp, lateral palatine process; mp, medial palatine process; mxf, facet for maxilla; pcf, paracanine fossa; pss, paraseptal shelf; sp, septal process; vo, vomer; vp, vomerine process; vs, vomer shelf.