Text-fig. 5. Metacheiromys marshi, AMNH 131777, left petrosal isosurface from CT scans in tympanic view; the posttympanic process of the squamosal and some possible entotympanic are also included. a – isosurface; b – line drawing with labels. Numbers 1 to 4 indicate depressions on medial flange. Abbreviations: ams – anteromedial septum, aptt – anteroventral process of tegmen tympani, cct – canal for chorda tympani nerve, ci – crista interfenestralis, cof – cochlear fossula, cp – crista parotica, ctp – caudal tympanic process, en? – possible entotympanic, epc – epitympanic crest, ew – epitympanic wing, fc – facial canal, fv – fenestra in Skeletal Anatomy Of The Basicranium And Auditory Region In The Metacheiromyid Palaeanodont Metacheiromys (Mammalia, Pholidotamorpha) Based On High-Resolution Ct Scans