Scientists use diagrams called cladograms to show evolutionary relationships.

The branching diagram beneath the pictures is a cladogram. Like the boxes, it shows how each group of animals is related to the others.

So each branch on the cladogram represents a group of organisms that share special characteristics inherited from a common ancestor. Cladograms can be used to illustrate evolutionary relationships and patterns of divergence.

Deinonychus © 1995 B. Cunningham; Archaeopteryx by Dave Smith, © UCMP; Grey Crowned Crane (Balearica regulorum) and Bald Eagle (Haliaeetus leucocephalus) by Gerald and Buff Corsi, © 2003 and 2004, respectively, California Academy of Sciences.