【How-to】Do humans have sectorial premolar

Primates are phylogenetically divided into those with a rhinarium, the Strepsirrhini (the prosimians: the lorises, and the lemurs); and those without a rhinarium, the Haplorhini, (the Simians: monkeys, apes, and humans). In place of the rhinarium, Haplorhini have a more mobile, continuous, dry upper lip.