The rhinarium is that wet naked surface around the nostrils of the nose in most mammals. Colloquially it might be called a "wet snout".

Primates are phylogenetically divided into Strepsirrhini ("lower primates" with rhinariums) and Haplorrhini ("higher primates" without rhinariums).

The presence of a rhinarium is associated with general features of the skull, especially the lateral placement of the eyes, and its absence with front-facing eyes. Mammals with rhinariums have a stronger sense of olfaction.

Animal anatomy | Head and neck