Aerodynamics of Soft Flapping Wings of Caudipteryx
This study explores the aerodynamic capacity of feathered forelimbs of Caudipteryx, the most basal non-volant maniraptoran dinosaur, with particular focus on flapping during terrestrial locomotion on a flat, horizontal substrate. In order to seek this subject, Caudipteryx and its wings have been modeled theoretically based on measuring the fossil data of Caudipteryx (IVPP V12344 and IVPP V12430). We divided the wings into various elements to enhance the analysis accuracy, and lift and thrust forces were estimated using a mathematical model and metabolic energy required to flap the forelimbs was estimated. Here we show that flapping feathered wings of flightless Caudipteryx would generate small amounts of aerodynamic forces based on our kinematic assumptions. Although the function of pennaceous feathers in oviraptorosaurs is uncertain and the feathers of dinosaur were believed not to originate for flight, theoretical analyses indicate that the feathered wings of Caudipteryx, could have produced small aerodynamic forces in rapid terrestrial locomotion. The winged Oviraptorosaurs utilized their feathered wings to produce aerodynamic forces in cursorial activities. Modeling of flapping while running showed similar limited aerodynamic force production.
KeywordsSoft flapping wings Aerodynamics Flight evolution Caudipteryx
The authors appreciate Prof. Dr. Corwin Sullivan from the Department of Biological Sciences, University of Alberta, Canada, Prof. Dr. Zhong-He Zhou and Prof. Dr. Min Wang from the Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing, 100044, P. R. China for their kind suggestions.
Y.S.T. deduced formulas and prepared programs, simulations, tables and figures and wrote the first draft of the manuscript; J.-S.Z. supervised the project and provided the major suggestions in revision; All authors discussed the results and commented on the manuscript and contributed ideas to manuscript development and data analysis.
This project was supported by the National Natural Science Foundation of China under grant 51575291, the National Major Science and Technology Project of China under grant 2015ZX04002101, State Key Laboratory of Tribology, Tsinghua University, and the 221 program of Tsinghua University.
The authors declare that they have no competing interests.
- 1.Ostrom, J.H.: Bird flight: how did it begin? Am. Sci. 67, 46–56 (1979)Google Scholar
- 4.Schaller, N.U.: Structural attributes contributing to locomotor performance in the ostrich. Ph.D. dissertation, University of Heidelberg, 129 p. (2008)Google Scholar
- 8.Lewin, R.: How did vertebrates take to the air? Sci. New Ser. 221, 38–39 (1983)Google Scholar
- 9.Gibbons, A.: New feathered fossil brings dinosaurs and birds closer. Sci. New Ser. 274, 720–721 (1996)Google Scholar
- 11.Henderson, D.M.: Estimating the masses and centers of mass of extinct animals by 3-D mathematical slicing. Paleobiology 25, 88–106 (1999)Google Scholar
- 14.Dyke, G.J., Norell, M.A.: Caudipteryx as a non avialan theropod rather than a flightless bird. Acta Palaeontol. Pol. 50(1), 101–116 (2005)Google Scholar
- 22.Zhou, Z., Zhang, F.C.: Origin and early evolution of feathers: evidence from the early cretaceous of China. Acta Zoologica Sinica 52(Suppl.), 125–128 (2006)Google Scholar
- 23.Zhou, Z.H., Wang, X.L.: A new species of Caudipteryx from the Yixian Formation of Liaoning, Northeast China. Vertebrata PalAsiatica 38, 111–127 (2000)Google Scholar
- 29.Zhou, Z., Wang, X.L., Zhang, F.C., Xu, X.: Important features of Caudipteryx evidence from two nearly complete new specimens. Vertebr PalAsiat 38, 241–254 (2000)Google Scholar
- 30.Norberg, U.M.: Vertebrate Flight in Zoophysiology (1989). ISBN 9783642838507Google Scholar
- 31.Henk, T.: The Simple Science of Flight (2009). ISBN 9780262513135Google Scholar
- 33.Baumel, J.J. (ed.): Handbook of Avian Anatomy. Nuttal Orn. Club, Cambridge (1993)Google Scholar
- 35.Woolley, J.D.: The functional morphology of the avian flight muscle M. Coracobrachialis posterior. J. Exp. Biol. 203, 1767–1776 (2000)Google Scholar
- 38.He, T., Wang, X.L., Zhou, Z.: A new genus and species of Caudipteryx dinosaur from the Lower Cretaceous Jiufotang Formation of Western Liaoning China. Vertebrata PalAsiatica 46, 178–189 (2008)Google Scholar
- 42.Delaurier, J.D., Harris, J.M.: A study of mechanical flapping wing flight. Aeronaut. J. 97, 277–286 (1993)Google Scholar
- 43.Kamakoti, R., et al.: A computational study for biological flapping wing flight. Trans. Aeronaut. Astronaut. Soc. Republic China 32(4), 265–279 (2000)Google Scholar
- 44.Delaurier, J.D.: An ornithopter wing design. Can. Aeronaut. Space J. 40, 10–18 (1994)Google Scholar
- 45.Delaurier, J.D.: An aerodynamic model for flapping wing flight. Aeronaut. J. 97, 125–130 (1993)Google Scholar
- 47.Jones, R.T.: The Unsteady Lift of a Wing of Finite Aspect Ratio. NACA Report 681 (1940)Google Scholar
- 48.Delaurier, J.D.: The development of an efficient ornithopter wing. Aeronaut. J. 97, 153–162 (1993)Google Scholar
- 49.Delaurier, J.D., Larijani, R.F.: A nonlinear aeroelastic model for the study of flapping wing flight, chapter 18. In: The American Institute of Aeronautics and Astronautics (2001)Google Scholar
- 51.Hoerner, S.F.: Fluid dynamic drag. Brick Town, NJ 2, 1–16 (1965)Google Scholar
- 52.Garrick, I.E.: Propulsion of a Flapping and Oscillating Aerofoil. NACA Report 567 (1936)Google Scholar
- 53.Hoerner, S.F.: Pressure drag, fluid dynamic drag. Brick Town, NJ, 3–16 (1965)Google Scholar