Three-dimensional reconstructions of details of the alisphenoid region (a, b) and the auditory bulla (c, d) based on micro-CT data of the holotypes of Mindomys kutuku sp. nov. (a, c MECN 5809; Cordillera de Kutukú, Ecuador) and Mindomys hammondi (b, d NHMUK 13.10.24.58; Mindo, Ecuador). Acronyms: aalc, anterior opening of alisphenoid canal; ab, auditory bulla; al, alisphenoid; als, alisphenoid strut; bet, bony Eustachian tube; bo, basioccipital; cc, carotid canal, cty, crista tympanica; fo, foramen ovale; bmt, buccinators-masticatory trough; pt, petrosal; sfr, sphenofrontal foramen; sq, squamosal; stf, stapedial foramen; rpm, rostral process of malleus. Figures are not to scale to facilitate comparisons.