Shake Your Tail Feathers
New fossils from the Gobi Desert indicate that tail feather-fans were widespread among oviraptorosaurs. Analysis of the unique form of oviraptorosaur tails indicates that they were also uniquely adapted for flexibility and muscular dexterity. Put it all together, and these dinosaurs seem to have what it took to wave, waggle, and flaunt their back-ends.
Persons WS IV, Currie P, Norell M. 2013. Oviraptorosaur tail forms and functions. Acta Palaeontologica Polonica 59: 553-567.