Feathered dinosaur

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Archaeopteryx feather, showing the off-centre rachis of a typical flight feather. Solnhofen 1860

A feathered dinosaur is a dinosaur with feathers. It is now thought that all coelurosaur, and perhaps all theropod, dinosaurs had feathers.

The realization that dinosaurs are closely related to birds raised the possibility of feathered dinosaurs. Fossils of Archaeopteryx include well-preserved feathers, but it was not until the early 1990s that clearly non-bird dinosaur fossils were discovered with preserved feathers. Since then, more than twenty genera of theropods have been discovered to be feathered.

Most of these fossils come from the Yixian formation in China. The fossil feathers of one specimen, Shuvuuia deserti, have tested positive for beta-keratin, the main protein in bird feathers, in immunological tests.[1]

Fossil evidence[change | edit source]

Sinosauropteryx fossil, first fossil of a definitively non-avialan dinosaur with feathers

After a century without clear evidence, well-preserved fossils of feathered dinosaurs were discovered during the 1990s, and more continue to be found. The fossils were preserved in a Lagerstätte — a sedimentary deposit exhibiting remarkable richness and completeness in its fossils — in Liaoning, China. The area had repeatedly been smothered in volcanic ash produced by eruptions in Inner Mongolia 124 million years ago, during the Lower Cretaceous. The fine-grained ash preserved the living organisms that it buried in fine detail. The area was teeming with life, with millions of leaves, angiosperms (the oldest known), insects, fish, frogs, salamanders, mammals, turtles, lizards and crocodilians discovered to date.

The most important discoveries at Liaoning have been a host of feathered dinosaur fossils, with a steady stream of new finds filling in the picture of the dinosaur-bird connection and adding more to theories of the evolutionary development of feathers and flight. Norell et al. (2007) reported quill knobs from an ulna of Velociraptor mongoliensis, and these are strongly correlated with large and well-developed secondary feathers.[2]

A nesting Citipati osmolskae specimen, at the AMNH.

Behavioural evidence, in the form of an oviraptorosaur on its nest, showed another link with birds. Its forearms were folded, like those of a bird.[3] Although no feathers were preserved, it is likely that these would have been present to insulate eggs and juveniles.[4]

Evidence in amber[change | edit source]

In 2011, samples of amber were discovered to contain preserved feathers from the Cretaceous period, with evidence that they were from both dinosaurs and birds. Initial analysis suggests that some of the feathers were used for insulation, and not flight.[5][6]

Current knowledge[change | edit source]

List of dinosaurs with evidence of feathers[change | edit source]

Fossil of Sinornithosaurus, the first evidence of feathers in dromaeosaurids
Cast of a Caudipteryx fossil with feather impressions and stomach content
Fossil of Microraptor gui impressions of feathered wings
Fossil cast of NGMC 91, an unnamed species
Jinfengopteryx elegans fossil

A number of non-avialan dinosaurs are now known to have been feathered. Direct evidence of feathers exists for the following genera, listed in the order currently accepted evidence was first published. The evidence consists of feather impressions, or convincing skeletal or chemical evidence. This would be the presence of quill knobs (the anchor points for wing feathers on the forelimb) or a pygostyle (the fused vertebrae at the tail tip which often supports large feathers).

For comparison: Archaeopteryx (1861; avialan)[7][8] Definitely had working flight feathers with off-centre rachis (stem). Otherwise, apart from the front limbs, a typical small carnivorous dinosaur.

  1. Wellnhoferia 1988; controversial re-naming of one of the Solnhofen specimens of Archaeopteryyx.[8][9][10]
  2. Avimimus 1987; inferred from possible quill knobs.[11][12]
  3. Sinosauropteryx 1996; coat of filament-like feathers[13]
  4. Protarchaeopteryx 1997;[14]
  5. Caudipteryx 1998;[15]
  6. Rahonavis 1998; inferred quill knobs.[16][17]
  7. Shuvuuia (1999)[1]
  8. Sinornithosaurus (1999)[18]
  9. Beipiaosaurus (1999)[19]
  10. Microraptor (2000)[20]
  11. Nomingia (inferred 2000: pygostyle)[21]
  12. NGMC 91 (2001)[22]
  13. Yixianosaurus (2003)[23]
  14. Dilong (2004)[24]
  15. Pedopenna (2005; possibly avialan[25])[26]
  16. Jinfengopteryx (2005)[27][28]
  17. Juravenator (2006)[29][30]
  18. Sinocalliopteryx (2007)[31]
  19. Velociraptor (inferred 2007: quill knobs)[2]
  20. Similicaudipteryx (inferred 2008: pygostyle; confirmed 2010)[32][33]
  21. Anchiornis (2009)[34]
  22. Tianyulong? (2009)[35]
  23. Concavenator? (inferred 2010: quill knobs?)[36]
  24. Xiaotingia (2011)[8]

Related pages[change | edit source]

References[change | edit source]

  1. 1.0 1.1 Schweitzer, M.H. et al. (1999). "Beta-keratin specific immunological reactivity in feather-like structures of the Cretaceous Alvarezsaurid, Shuvuuia deserti". Journal of Experimental Zoology 285 (2): 146–57. doi:10.1002/(SICI)1097-010X(19990815)285:2<146::AID-JEZ7>3.0.CO;2-A. PMID 10440726.
  2. 2.0 2.1 Turner, A.H.; Makovicky, P.J.; and Norell, M.A. (2007). "Feather quill knobs in the dinosaur Velociraptor" (pdf). Science 317 (5845): 1721. doi:10.1126/science.1145076. PMID 17885130. http://www.sciencemag.org/cgi/reprint/317/5845/1721.pdf.
  3. Norell M.A. et al. (1995). "A nesting dinosaur". Nature 378 (6559): 774–776. doi:10.1038/378774a0.
  4. Hopp, Thomas J. & Orsen, Mark J. 2004. In Philip J. Currie, Eva B. Koppelhus and Martin A. Shugar (eds) Feathered Dragons: studies on the transition from dinosaurs to birds. Chapter 11: Dinosaur brooding behavior and the origin of flight feathers. Indiana University Press. Bloomington IN. USA.
  5. CBC News: Dinosaur feathers found in Alberta amber
  6. BBC News: Dinosaur feather evolution trapped in Canadian amber
  7. von Meyer H. 1861. Archaeopteryx litographica (Vogel-Feder) und Pterodactylus von Solenhofen. Neues Jahrbuch für Mineralogie, Geognosie, Geologie und Petrefakten-Kunde. 1861: 678–679, plate V [Article in German] Fulltext at Google Books.
  8. 8.0 8.1 8.2 Xing Xu, Hailu You, Kai Du and Fenglu Han (28 July 2011). "An Archaeopteryx-like theropod from China and the origin of Avialae". Nature 475 (7357): 465–470. doi:10.1038/nature10288. http://www.nature.com/nature/journal/v475/n7357/full/nature10288.html.
  9. Wellnhofer, P. (1988). "A new specimen of Archaeopteryx". Science 240: 1790-1792. doi:10.1126/science.240.4860.1790.
  10. Elżanowski A. 2001. A new genus and species for the largest specimen of Archaeopteryx. Acta Palaeontologica Polonica 46 (4):519–532 HTML abstract
  11. Kurzanov, S.M. (1987). "Avimimidae and the problem of the origin of birds." Transactions of the Joint Soviet-Mongolian Paleontological Expedition, 31: 5-92. [in Russian]
  12. Chiappe, L.M. and Witmer, L.M. 2002. Mesozoic birds: above the heads of dinosaurs. Berkeley: University of California Press, 536 pp. ISBN 0-520-20094-2
  13. Ji Q., Ji S. (1996). "On discovery of the earliest bird fossil in China and the origin of birds". Chinese Geology 10 (233): 30–33.
  14. Ji, Q., and Ji, S. 1997. "A Chinese archaeopterygian, Protarchaeopteryx gen. nov." Geological Science and Technology (Di Zhi Ke Ji), 238: 38-41. Translated By Will Downs Bilby Research Center Northern Arizona University January, 2001
  15. Currie, Philip J. et al. (1998). Nature 393 (6687): 753–761. doi:10.1038/31635.
  16. Agnolin F.L. & Novas F.E. (2011). "Unenlagiid theropods: are they members of the Dromaeosauridae (Theropoda, Maniraptora)?" (PDF). Anais da Academia Brasileira de Ciências 83: 117–162. doi:10.1590/S0001-37652011000100008. http://www.scielo.br/pdf/aabc/v83n1/v83n1a08.pdf. Retrieved 2011-04-23.
  17. Forster, Catherine A.; Sampson, Scott D.; Chiappe, Luis M. & Krause, David W. (1998a). "The theropod ancestry of birds: new evidence from the late Cretaceous of Madagascar". Science 279 (5358): 1915–1919. doi:10.1126/science.279.5358.1915. PMID 9506938. (HTML abstract)
  18. Wu, Xiao-Chun; Xu, Xing; Wang, Xiao-Lin (1999). Nature 401 (6750): 262–266. doi:10.1038/45769.
  19. Xu, Xing; Zhao, Xijin; Clark, James M. (2001). "A new therizinosaur from the Lower Jurassic lower Lufeng Formation of Yunnan, China". Journal of Vertebrate Paleontology 21 (3): 477–483. doi:10.1671/0272-4634(2001)021[0477:ANTFTL]2.0.CO;2. ISSN 0272-4634.
  20. Xu, Xing; Zhou, Zhonghe; Wang, Xiaolin (2000). "The smallest known non-avian theropod dinosaur" (PDF). Nature 408 (6813): 705–708. doi:10.1038/35047056. PMID 11130069. http://research.amnh.org/%7Esunny/microraptor.pdf.
  21. Barsbold R., Osmólska H., Watabe M., Currie P.J., Tsogtbaatar K. (2000). "New Oviraptorosaur (Dinosauria, Theropoda) From Mongolia: The First Dinosaur With A Pygostyle" (PDF). Acta Palaeontologica Polonica 45 (2): 97–106. http://www.app.pan.pl/archive/published/app45/app45-097.pdf.
  22. Ji, Qiang; Norell, Mark A.; Gao, Ke-Qin; Ji, Shu-An; Ren, Dong (2001). "The distribution of integumentary structures in a feathered dinosaur". Nature 410 (6832): 1084–1087. doi:10.1038/35074079. PMID 11323669.
  23. Xu X., Wang X.-L. (2003). "A new maniraptoran from the Early Cretaceous Yixian Formation of western Liaoning". Vertebrata PalAsiatica 41 (3): 195–202.
  24. Xu, X., Norell, M. A., Kuang, X., Wang, X., Zhao, Q., Jia, C. (2004). "Basal tyrannosauroids from China and evidence for protofeathers in tyrannosauroids". Nature 431 (7009): 680–684. doi:10.1038/nature02855. PMID 15470426. http://www.nature.com/nature/journal/v431/n7009/full/nature02855_fs.html.
  25. Hone D.W.E., Tischlinger H., Xu X., Zhang F. (2010). Farke, Andrew Allen. ed. "The extent of the preserved feathers on the four-winged dinosaur Microraptor gui under ultraviolet light". PLoS ONE 5 (2): e9223. doi:10.1371/journal.pone.0009223. http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0009223.
  26. Xu, Xing; Zhang, Fucheng (2005). "A new maniraptoran dinosaur from China with long feathers on the metatarsus". Naturwissenschaften 92 (4): 173–177. doi:10.1007/s00114-004-0604-y. PMID 15685441.
  27. Ji Q., Ji S., Lu J., You H., Chen W., Liu Y., Liu Y. (2005). "First avialan bird from China (Jinfengopteryx elegans gen. et sp. nov.)". Geological Bulletin of China 24 (3): 197–205.
  28. Turner, Alan H.; Pol, Diego; Clarke, Julia A.; Erickson, Gregory M.; and Norell, Mark (2007). "A basal dromaeosaurid and size evolution preceding avian flight" (pdf). Science 317 (5843): 1378–1381. doi:10.1126/science.1144066. PMID 17823350. http://www.sciencemag.org/cgi/reprint/317/5843/1378.pdf.
  29. Goehlich U.B., Tischlinger H., Chiappe L.M. (2006). "Juraventaor starki (Reptilia, Theropoda) ein nuer Raubdinosaurier aus dem Oberjura der Suedlichen Frankenalb (Sueddeutschland): Skelettanatomie und Wiechteilbefunde". Archaeopteryx 24: 1–26.
  30. Chiappe, Luis M.; Göhlich, Ursula B. (2010). "Anatomy of Juravenator starki (Theropoda: Coelurosauria) from the Late Jurassic of Germany". Neues Jahrbuch für Geologie und Paläontologie - Abhandlungen 258 (3): 257–296. doi:10.1127/0077-7749/2010/0125.
  31. Ji S., Ji Q., Lu J., Yuan C. (2007). "A new giant compsognathid dinosaur with long filamentous integuments from Lower Cretaceous of Northeastern China". Acta Geologica Sinica 81 (1): 8–15.
  32. He T., Wang X.-L., Zhou Z.-H. (2008). "A new genus and species of caudipterid dinosaur from the Lower Cretaceous Jiufotang Formation of western Liaoning, China". Vertebrata PalAsiatica 46 (3): 178–189.
  33. Xu, Xing; Zheng, Xiaoting; You, Hailu (2010). "Exceptional dinosaur fossils show ontogenetic development of early feathers". Nature 464 (7293): 1338–1341. doi:10.1038/nature08965. PMID 20428169.
  34. Xu, X., Zhao, Q., Norell, M., Sullivan, C., Hone, D., Erickson, G., Wang, X., Han, F. and Guo, Y. (in press). "A new feathered maniraptoran dinosaur fossil that fills a morphological gap in avian origin." Chinese Science Bulletin, 6 pages, accepted November 15, 2008.
  35. Zheng, Xiao-Ting; You, Hai-Lu; Xu, Xing; Dong, Zhi-Ming (2009). "An Early Cretaceous heterodontosaurid dinosaur with filamentous integumentary structures". Nature 458 (7236): 333–336. doi:10.1038/nature07856. PMID 19295609.
  36. Ortega, Francisco; Escaso, Fernando; Sanz, José L. (2010). "A bizarre, humped Carcharodontosauria (Theropoda) from the Lower Cretaceous of Spain". Nature 467 (7312): 203–206. doi:10.1038/nature09181. PMID 20829793.