A selected anatomical features of the skull of Neacomys marci sp. nov. based on the holotype (MECN 6232; Estación Fisher, Ecuador): posterior portion of the skull in lateral view B lateral view of alisphenoid bone region C right auditory region in ventral view D ventral view of basicranial region E dorsal view (roofing bones of braincase removed) of basicranial region F cross-section of the cranium. Abbreviations: ab, auditory bulla; bet, bony Eustachian tube; bmt, buccinators-masticatory trough; bo, basioccipital; bs, basisphenoid; cc, carotid canal; etI, ethmoturbinal I; etII, ethmoturbinal II; etIII, ethmoturbinal III; fo, foramen ovale; ft1, frontoturbinal 1; ft2, frontoturbinal 2; it, interturbinal; ls, lamina semicircularis; mas, mastoid capsule; mlf, middle lacerate foramen; palc, posterior opening of the alisphenoid canal; pet, petrosal; pgf, postglenoid foramen; ppp, posterior palatal pits; ps, presphenoid; sag, squamosal alisphenoid groove; sfr, sphenofrontal foramen; stf, stapedial foramen; ssf, subsquamosal fenestra; tt, tegmen tympani; Pictures are three-dimensional reconstructions based on micro-CT data.