The term comes from the Greek roots selene (crescent), and odous (tooth). They differ from human molars in that the occlusal surface is not covered in enamel; rather, the layers of enamel, dentine, and cementum are all exposed, with cementum in the middle, surrounded by a layer of enamel, then a layer of dentine, all wrapped in a second outer layer of enamel.
Viewed from the side, selenodont teeth form a series of triangular cusps. The combination of triangular profiles with ridges formed by the exposed layers makes the sideways jaw-motion of ruminants (think of a cow chewing) an effective way to break-up tough vegetable matter.
- Dorit, Robert L.; Warren F. Walker, Jr.; Robert D. Barnes (1991). Zoology. Orlando, Florida, USA: Saunders College Publishing. pp. 925–926.