Figure 3

Evolutionary correlation between the pygostyle, tail length, and possible display behavior. This mirror tree, constructed in Mesquite [49], shows the correspondence between tail adaptations in theropod dinosaurs, with presence (black) or absence (white) of a pygostyle mapped onto the left tree, and presence (black) or absence (white) of evidence that the tail may have been used in display on the right tree. Note that the tails of species in bold have shortened tails relative to basal theropods.