This is a collection of 10,956 photographs of mammalian crania, which have been taken with a high-resolution digital camera since 1997. The materials include 1826 cranial specimens, ranging from insectivores to elephants, which have been macerated in Japan during the past 35 years and prepared for osteological studies. Of the 16 orders in the database, primates comprise the major group with 704 specimens. Each cranium, the orbitomeatal or palatine plane of which was placed horizontally, was photographed from six different angles (anterior, posterior, left, right, superior, and inferior) at a long distance from the camera through a telephoto or telemacro lens. The long-distance shot decreases perspective distortion that may lead to measurement errors when studying crania profiles. For the cranial images whose anatomical direction is deviated from the lens' optical axis due to technical inaccuracy, adjustments in the 3-D rotations on the cranium's anatomical axes have been repeated until the setting error is minimized. No digital enhancement has been applied to captured images, which are JPEG compressed and of 6 mega pixels. The high-resolution images enable us to observe specific bony characteristics in detail and to compare them on a computer screen. For data browsing, cranial images can be searched using the (1) phylogenetic table, (2) Japanese name, (3) English name, and (4) scientific name. In the page of search results, four caliper measurements and additional text (taxonomy, sex, and age) are available for every specimen. Photographs of living mammals in zoos may appear for some species. Additionally, cranial images with the mandible in frontal and lateral views are present for almost every primate species. Finally, we impose no restrictions on the use of these skeletal images for noncommercial (academic or hobby) purpose.