Abstract
Recently a specimen of Sapeornis was described with feathers around the ankle joint, the first basal bird with metatarsal feathers. The discovery of several groups of paravians with feathered distal hindlimbs has been used as evidence that flight in Aves evolved through a tetrapteryx stage. However, most specimens of Sapeornis do not preserve feathers around the feet, and these feathers are clearly absent in at least one exceptional specimen preserving skin and feather impressions. This suggests that the presence of ankle feathers in Sapeornis may alternatively be interpreted as ornamentation. Basal birds show more ornamental tail morphologies than aerodynamic ones suggesting that sexual selection played a dominant role in shaping tail plumage. Feathers on the forelimbs initially evolved for a purpose other than flight and we propose aerodynamics was not the driving force in hindlimb feather evolution. We suggest that feathers as a means of visual communication played a very important role in the evolution of paravian plumage.
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References
Chiappe, L.M., Bo, Z., O’Connor, J.K., Gao, C.-H., Wang, X.-R., et al., A new specimen of the Early Cretaceous bird Hongshanornis longicresta: insights into the aerodynamics and diet of a basal ornithuromorph, Peer J., 2014, vol. 2. http://dx.doi.org/10.7717/peerj.234
Chinsamy, A., Chiappe, L.M., Marugan-Lobon, J., Gao, C.-H., and Zhang, F.-J., Gender identification of the Mesozoic bird Confuciusornis sanctus, Nat. Commun., 2013, vol. 4. doi 10.1038/ncomms2377
Clarke, J.A., Zhou, Z., and Zhang, F., Insight into the evolution of avian flight from a new clade of Early Cretaceous ornithurines from China and the morphology of Yixianornis grabaui, J. Anat., 2006, vol. 208, pp. 287–308.
Gao, C.-H., Chiappe, L.M., Zhang, F.-J., Pomeroy, D.L., Shen, C.-Z., et al., A subadult specimen of the Early Cretaceous Bird Sapeornis chaoyangensis and a taxonomic reassessment of sapeornithids, J. Vertebr. Paleontol., 2012, vol. 32, pp. 1103–1112.
Gill, F.B., Ornithology, 3rd ed., New York: Freeman, 2007.
Hou, L., Martin, L.D., Zhou, Z., and Feduccia, A., Early adaptive radiation of birds: Evidence from fossils from northeastern China, Science, 1996, vol. 274, pp. 1164–1167.
Hu, D., Hou, L., Zhang, L., and Xu, X., A pre-Archaeopteryx troodontid theropod from China with long feathers on the metatarsus, Nature, 2009, vol. 461, pp. 640–643.
Hu, D.-Y., Li, L., Hou, L.-H., and Xu, X., A new sapeomithid bird from China and its implication for early avian evolution, Acta Geol. Sinica, Engl. Ed., 2010, vol. 84, pp. 472–482.
Longrich, N., Structure and function of hindlimb feathers in Archaeopteryx lithographica, Paleobiology, 2006, vol. 32, pp. 417–431.
Møller, A.P. and Hedenström, A., Comparative evidence for costs of secondary sexual characters: adaptive vane emargination of ornamented feathers in birds, J. Evolut. Biol., 1999, vol. 12, pp. 296–305.
Norberg, U.M., Evolution of flight in birds: aerodynamic, mechanical, and ecological aspects, in The Beginnings of Birds, Willibaldsburg: Freunds des Jura-Museums Eichstätt, 1985, pp. 293–302.
O’Connor, J.K., A systematic review of Enantiornithes (Aves: Ornithothoraces), Unpublished PhD Dissertation, Los Angeles: Univ. of Southern California, 2009.
O’Connor, J.K., Wang, X.-R., Chiappe, L.M., Gao, C.-H., Meng, Q.-J., et al., Phylogenetic support for a specialized clade of Cretaceous enantiornithine birds with information from a new species, J. Vertebr. Paleontol., 2009, vol. 29, pp. 188–204.
O’Connor, J.K., Wang, X.-L., Sullivan, C., Zheng, X.-T., Tubaro, P.L., et al., The unique caudal plumage of Jeholornis and complex tail evolution in early birds, Proc. Natl. Acad. Sci. U. S. A., 2013, vol. 110, pp. 17404–17408.
Padian, K. and Chiappe, L.M., The origin and early evolution of birds, Biol. Rev., 1998, vol. 73, pp. 1–42.
Provini, P., Zhou, Z.-H., and Zhang, F.-C., A new species of the basal bird Sapeornis from the Early Cretaceous of Liaoning, China, Vertebrata PalAsiatica, 2008, vol. 47, pp. 194–207.
Pu, H.-Y., Chang, H.-L., Lu, J.-C., Wu, Y.-H., Xu, L., et al., A new juvenile specimen of Sapeornis (Pygostylia: Aves) from the Lower Cretaceous of northeast China and allometric scaling of this basal bird, Paleontol. Res., 2013, vol. 17, pp. 27–38.
Rayner, J.M.V., Mechanical and ecological constraints on flight evolution, in The Beginnings of Birds, Willibaldsburg: Freunds des Jura-Museums Eichstätt, 1985, pp. 279–288.
Stettenheim, P.R., The integumentary morphology of modern birds: an overview, Am. Zool., 2000, vol. 40, pp. 461–477.
Thomas, A.L.R., On the aerodynamics of birds’ tails, Phil. Trans. R. Soc. London B, 1993, vol. 340, pp. 361–380.
Xu, X. and Zhang, F., A new maniraptoran dinosaur from China with long feathers on the metatarsus, Naturwissenschaften, 2005, vol. 92, pp. 173–177.
Xu, X., Zhou, Z., Wang, X., Kuang, X., and Du, X., Fourwinged dinosaurs from China, Nature, 2003, vol. 421, pp. 335–340.
Xu, X., You, H.-L., Kai, D., and Han, F.-L., An Archaeopteryx-like theropod from China and the origin of Avialae, Nature, 2011, vol. 475, pp. 465–475.
You, H.-L., Lamanna, M.C., Harris, J.D., Chiappe, L.M., O’Connor, J., et al., A nearly modern amphibious bird from the Early Cretaceous of northwestern China, Science, 2006, vol. 312, pp. 1640–1643.
Yuan, C., A new genus and species of Sapeornithidae from Lower Cretaceous in Western Liaoning, China, Acta Geol. Sin., 2008, vol. 82, pp. 48–55.
Zhang, F. and Zhou, Z., Leg feathers in an Early Cretaceous bird, Nature, 2004, vol. 431, p. 925.
Zheng, X., Zhang, Z., and Hou, L., A new enantiornitine bird with four long rectrices from the Early Cretaceous of northern Hebei, China, Acta Geol. Sin., 2007, vol. 81, pp. 703–708.
Zheng, X.-T., Wang, X.-L., O’Connor, J.K., and Zhou, Z.-H., Insight into the early evolution of the avian sternum from juvenile enantiornithines, Nat. Commun., 2012, vol. 3. doi 10.1038/ncomms2104
Zheng, X.-T., O’Connor, J.K., Huchzermeyer, F.W., Wang, X.-L., Wang, Y., et al., Exceptional preservation of ovarian follicles in Early Cretaceous birds and implications for early evolution of avian reproductive behaviour, Nature, 2013a, vol. 495, pp. 507–511.
Zheng, X.-T., Zhou, Z.-H., Wang, X.-L., Zhang, F.-C., Zhang, X.-M., et al., Hind wings in basal birds and the evolution of leg feathers, Science, 2013b, vol. 339, pp. 1309–1312. Zhou, Z. and
Zhang, F., Largest bird from the Early Cretaceous and its implications for the earliest avian ecological diversification, Naturwissenschaften, 2002, vol. 89, pp. 34–38.
Zhou, Z. and Zhang, F., Anatomy of the primitive bird Sapeornis chaoyangensis from the Early Cretaceous of Liaoning, China, Can. J. Earth Sci., 2003, vol. 40, pp. 731–747.
Zhou, Z. and Zhang, F., Discovery of an ornithurine bird and its implication for Early Cretaceous avian radiation, Proc. Natl. Acad. Sci. U. S. A., 2005, vol. 102, pp. 18998–19002.
Zhou, S., Zhou, Z.-H., and O’Connor, J.K., A new toothless ornithurine bird (Schizooura lii gen. et sp. nov.) from the Lower Cretaceous of China, Vertebrata PalAsiatica, 2012, vol. 50, pp. 9–24.
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Published in Russian in Zoologicheskii Zhurnal, 2014, Vol. 93, No. 10, pp. 1166–1172.
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O’Connor, J.K., Chang, H. Hindlimb feathers in paravians: Primarily “wings” or ornaments?. Biol Bull Russ Acad Sci 42, 616–621 (2015). https://doi.org/10.1134/S1062359015070079
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DOI: https://doi.org/10.1134/S1062359015070079