An entity that is distantly related to the other creatures on the cladogram is the outgroup.
The outgroup, which is frequently thought to represent the ancestral condition from which the organisms in the cladogram later developed, aids in the rooting of the tree.
The use of chimpanzees as an outgroup, for instance, can be used to root a cladogram of hominid species.
Cladograms are tree-like diagrams that can be used to show the links between creatures throughout evolutionary history.
On a cladogram, a node is a collection of branches that come from the same node.