 A shelf-like ridge on the lower part of the crown (on an upper molar) is called a cingulum; the same feature on the lower molar a cingulid, and a minor cusp on these, for example, a cingular cuspule or conulid.The design that is considered one of the most important characteristics of mammals is a three-cusped shape called a tribosphenic molar.This molar design has two important features