Measurements are from specimens of Cynomys gunnisoni housed at the AMNH. Measurements were collected from digital images using Image J and recorded into an Excel spreadsheet. The column headings include: Specimen ID, Location, Year, Occipital condyle, zygomatic width, total skull length, whether skull sutures were fused, length of the upper right tooth row, and basicranial length. All measurements are reported in mm.