Skull of Monodelphis brevicaudata, modified from Wible (2003). Skull (A–D) and mandible (C) in dorsal (A), ventral (B), left lateral (C), and caudal (D) views. Abbreviations: an angular process; as alisphenoid; astp alisphenoid tympanic process; bo basioccipital; bs basisphenoid; coc coronoid crest; con mandibular condyle; cor coronoid process; ctpp caudal tympanic process of the petrosal; ec ectotympanic; eo exoccipital; fc fenestra cochleae; fm foramen magnum; fr frontal; ham pterygoid hamulus; inf incisive foramen; iof infraorbital foramen; ip interparietal; jf jugular foramen; ju jugal; lac lacrimal; lacf lacrimal foramen; m malleus; maf masseteric fossa; mapf major palatine foramen; mf mental foramen; mpf minor palatine foramen; mx maxilla; na nasal; oc occipital condyle; pa parietal; pal palatine; pcp paracondylar process of the exoccipital; pe petrosal; pmx premaxilla; pgp postglenoid process; ppt postpalatine torus; pptf foramen in the postpalatine torus; ps presphenoid; pt pterygoid; ptn posttemporal foramen; ptp posttympanic process; rtpp rostral tympanic process of the petrosal; so supraoccipital; sq squamosal; tl temporal line.