Carnassials are paired upper and lower teeth (either molars or premolars and molars) modified in such a way as to allow enlarged and often self-sharpening edges to pass by each other in a shearing manner. The modification arose separately in several groups of carnivorous mammals. Different pairs of teeth were involved in the separate modifications. In modern
Carnivora, the carnassials are the modified fourth upper
premolar and the first lower
molar. These teeth are also referred to as
sectorial teeth.