Dinosaurs and The Origin of Birds

James M Clark, George Washington University, Washington, DC, USA

Published online: February 2013

DOI: 10.1002/9780470015902.a0003322.pub2

The evolutionary relationships of birds have been debated ever since the discovery of a fossil bird, Archaeopteryx, in 1861, that has bird-like feathers but reptilian teeth and a long bony tail. Recent discoveries of feathered dinosaurs have confirmed analyses of bird relationships beginning in the 1970s that placed Archaeopteryx and birds within one group of dinosaurs, the Theropoda. Recognition of this relationship and discovery of a variety of new species have allowed evolutionary biologists to study for the first time many aspects of the transition from ground-living theropods to flying birds. Many new details about the evolution of feathers, reproductive features of birds and flight have emerged from these fossils and continue to emerge as new fossils are found. The precise relationships of birds to theropods is still debated, but the scansoriopterygids, dromaeosaurs and troodontids are amongst the closest relatives of birds.

Key Concepts:

  • The closest living relatives of birds are the crocodilians and together they form the group Archosauria.
  • The origins of birds lie with fossil archosaurs, which include dinosaurs, the flying reptiles called pterosaurs and the many fossil relatives of crocodilians.
  • Evolutionary relationships are studied using cladistic analysis of similarities shared amongst different species.
  • Cladistic analyses strongly support birds being closely related to a subgroup within the theropod dinosaurs called Coelurosauria and especially with the scansoriopterygid, dromaeosaur and troodontid coelurosaurs.
  • Fossil coelurosaurs with feathers from China provide convincing evidence that birds are coelurosaurs, and that during the course of evolution feathers arose before flight.

Keywords: birds; dinosaurs; feathers; phylogeny

Figure 1. The ‘London’ specimen of the primitive bird Archaeopteryx, housed at The Natural History Museum. Photograph courtesy of L Chiappe. © L. Chiappe.
Figure 2. An authentic ‘feathered dinosaur’ from Liaoning, China (Ji et al., 2001). This skeleton of Microraptor preserves dinosaurian features such as teeth with denticles and a foot with the first toe not rotated to the back and dromaeosaur features such as elongate processes on tail vertebrae. (a) Entire skeleton. (b) Detail of feathers. Photographs courtesy of Mick Ellison. © Mick Ellison.
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 References
    Bever GS, Gauthier JA and Wagner GP (2011) Finding the frame shift: digit loss, developmental variability, and the origin of the avian hand. Evolution and Development 13: 269–279.
    book Brochu C and Norell M (2001) "Time and trees: a quantitative assessment of temporal congruence in the bird origins debate". In: Gauthier JA and Gill F (eds) New Perspectives on the Origin and Early Evolution of Birds, pp. 511–535. New Haven, CT: Yale Peabody Museum.
    Chiappe LM and Göhlich UB (2010) Anatomy of Juravenator starki (Theropoda: Coelurosauria) from the Late Jurassic of Germany. Neues Jahrbuch für Geologie und Paläontologie–Abhandlungen 258: 257–296.
    Choiniere JN, Xu X, Clark JM et al. (2010) A basal alvarezsauroid theropod from the early Late Jurassic of Xinjiang, China. Science 327: 571–574.
    Clark JM, Norell MA and Chiappe L (1999) An oviraptorid skeleton from the Late Cretaceous of Ukhaa Tolgod, Mongolia, preserved in an avian-like brooding position over an oviraptorid nest. American Museum Novitates 3265: 1–36.
    Dial KP (2003) Wing-assisted incline running and the evolution of flight. Science 299: 402–404.
    Farmer CG and Sanders K (2010) Unidirectional airflow in the lungs of alligators. Science 327: 338–340.
    book Feduccia A (2012) Riddle of the Feathered Dragons: Hidden Birds of China. New Haven, CT: Yale University Press.
    Gauthier JA (1986) Saurischian monophyly and the origin of birds. Memoirs of the California Academy of Sciences 8: 1–47.
    book Gee H (ed.) (2002) Rise of the Dragon: Readings from Nature on the Chinese Fossil Record. Chicago: University of Chicago Press.
    Grellet-Tinner G, Chiappe L, Norell M and Bottjer D (2006) Dinosaur eggs and nesting behaviors: A paleobiological investigation. Palaeogeography, Palaeoclimatology and Palaeoecology 232: 294–321.
    Hedges SB (2012) Amniote phylogeny and the position of turtles. BMC Biology 10: 64–65.
    Huxley T (1870) Further evidence of the affinity between the dinosaurian reptiles and birds. Quarterly Journal of the Geological Society of London 26: 12–31.
    Ji Q, Norell MA, Gao KQ et al. (2001) The distribution of integumentary structures in a feathered dinosaur. Nature 410: 1084–1088.
    Lee AH and Werning S (2008) Sexual maturity in growing dinosaurs does not fit reptilian growth models. Proceedings of the National Academy of Sciences of the USA 105: 582–587.
    Longrich N (2006) Structure and function of hindlimb feathers in Archaeopteryx lithographica. Paleobiology 32: 417–431.
    Nesbitt S (2011) The early evolution of archosaurs: relationships and the origin of major clades. Bulletin of the American Museum of Natural History 352: 1–292.
    Nesbitt SJ, Turner AH, Spaulding M, Conrad JL and Norell MA (2009) The theropod furcula. Journal of Morphology 270(7): 856–879.
    O'Connor PM and Claessens LPAM (2005) Basic avian pulmonary design and flow-through ventilation in non-avian theropod dinosaurs. Nature 436: 253–256.
    Ostrom JH (1976) Archaeopteryx and the origin of birds. Biological Journal of the Linnean Society 8: 91–182.
    Rauhut OWM, Foth C, Tischlinger H and Norell MA (2012) Exceptionally preserved juvenile megalosauroid theropod dinosaur with filamentous integument from the Late Jurassic of Germany. Proceedings of the National Academy of Sciences of the USA 109: 11746–11751.
    Reisz RR and Sues H-D (2000) Palaeontology: the ‘feathers’ of Longisquama. Nature 408: 428.
    Schweitzer MH (2011) Soft tissue preservation in terrestrial Mesozoic vertebrates. Annual Review of Earth and Planetary Science 39: 187–216.
    Schweitzer MH, Watt JA, Avci R et al. (1999) Beta-keratin specific immunological reactivity in feather-like structures of the Cretaceous alvarezsaurid, Shuvuuia deserti. Journal of Experimental Biology 255: 146–157.
    Senter P, Kirkland JI, DeBlieux DD, Madsen S and Toth N (2012) New dromaeosaurids (Dinosauria: Theropoda) from the Lower Cretaceous of Utah, and the evolution of the dromaeosaurid tail. PLOS One 7: e36790.
    Sullivan C, Hone DWE, Xu X and Zhang F (2010) The asymmetry of the carpal joint and the evolution of wing folding in maniraptoran theropod dinosaurs. Proceedings of the Royal Society of London B 277: 2027–2033.
    Wagner GP and Gauthier JA (1999) 1,2,3=2,3,4: a solution to the problem of the homology of the digits in the avian hand. Proceedings of the National Academy of Sciences of the USA 96: 5111–5116.
    Wagner G (2005) The developmental evolution of avian digital homology: An update. Theory in Biosciences 124: 165–183.
    book Wellnhofer P (2009) Archaeopteryx: The Icon of Evolution. Munich: Verlag Dr Friedrich Pfeil.
    Witmer LM (1997) The evolution of the antorbital cavity of archosaurs: a study in soft-tissue reconstruction in the fossil record with an analysis of the function of pneumaticity. Society of Vertebrate Paleontology Memoir 3: 1–73.
    Xu X and Guo Y (2009) The origin and early evolution of feathers: insights from recent paleontological and neontological data. Vertebrata PalAsiatica 47: 311–329.
    Xu X, Clark JM, Mo J et al. (2009) A Jurassic ceratosaur from China helps clarify avian digital homologies. Nature 459: 940–944.
    Xu X, You H, Du K and Han FL (2011) An Archaeopteryx-like theropod from China and the origin of Avialae. Nature 475: 465–470.
    Zanno LE (2010) Osteology of Falcarius utahensis: characterizing the anatomy of basal therizinosaurs. Zoological Journal of the Linnaean Society 158: 196–230.
    Zelenitsky DK, Therrien F, Erickson GM et al. (2012) Feathered non-avian dinosaurs from North America provide insight into wing origins. Science 338: 510–514.
    Zhang F, Zhou Z, Xu X, Wang X and Sullivan C (2008) A bizarre Jurassic maniraptoran from China with elongate ribbon-like feathers. Nature 455: 1105–1108.
 Further Reading
    book Chang MM, Chen PJ, Wang Y, Wang YQ and Miao D (2008) The Jehol Fossils: The Emergence of Feathered Dinosaurs, Beaked Birds and Flowering Plants. NY: Academic Press.
    book Chiappe L (2007) Glorified Dinosaurs: The Origin and Early Evolution of Birds. NY: Wiley-Liss.
    book Chiappe L and Witmer L (2002) Mesozoic Birds: Above the Heads of the Dinosaurs. Berkeley, CA: University of California Press.
    book Currie PJ, Koppelhus EB, Shugar MA and Wright JL (eds) (2004) Feathered Dragons: Studies on the Transition from Dinosaurs to Birds. Bloomington, IN: Indiana University Press.
    book Gauthier JA and Gill LF (eds) (2001) New Perspectives on the Origin and Early Evolution of Birds. New Haven, CT: Yale Peabody Museum.
    book Long J and Schouten P (2008) Feathered dinosaurs: The origin of birds. NY: Oxford University Press.

Related Sub-Topics:

Diversification of Plants and Animals | Evolution of Novelty | Macroevolution | Reconstruction of Phylogeny | Fossils and Evolution
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Article Title: Dinosaurs and The Origin of Birds
 
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Clark, James M(Feb 2013) Dinosaurs and The Origin of Birds. In: eLS. John Wiley & Sons Ltd, Chichester. http://www.els.net [doi: 10.1002/9780470015902.a0003322.pub2]