Two distinct crown groups (in red) are illustrated, connected by an ancestor (black circle). The two groups form a larger crown group (lilac).

A crown group is a group of living species and their ancestors back to the most recent common ancestor. It is a term in cladistics and phylogenetics. It is a clade with at least some members that have survived to the present day. How a crown group is defined depends on which living species are chosen. One definition stresses the need for members of the crown group to have the clade's characteristic synapomorphy.