Journal of Ornithology

, Volume 155, Issue 4, pp 841–851 | Cite as

Jurassic archosaur is a non-dinosaurian bird

  • Stephen A. Czerkas
  • Alan FeducciaEmail author
Original Article


Re-examination utilizing Keyence 3D digital microscopy and low angled illumination of the fossil Scansoriopteryx, a problematic sparrow-size pre-Archaeopteryx specimen from the Jurassic Daohugou Biotas, provides new evidence which challenges the widely accepted hypothesis that birds are derived from dinosaurs in which avian flight originated from cursorial forms. Contrary to previous interpretations in which Scansoriopteryx was considered to be a coelurosaurian theropod dinosaur, the absence of fundamental dinosaurian characteristics demonstrates that it was not derived from a dinosaurian ancestry and should not be considered as a theropod dinosaur. Furthermore, the combination in which highly plesiomorphic non-dinosaurian traits are retained along with highly derived features, yet only the beginnings of salient birdlike characteristics, indicates that the basal origins of Aves stemmed from outside the Dinosauria and further back to basal archosaurs. Impressions of primitive elongate feathers on the forelimbs and hindlimbs suggest that Scansoriopteryx represents a basal form of “tetrapteryx” in which incipient aerodynamics involving parachuting or gliding was possible. Along with unique adaptations for an arboreal lifestyle, Scansoriopteryx fulfills predictions from the early twentieth century that the ancestors of birds did not evolve from dinosaurs, and instead were derived from earlier arboreal archosaurs which originated flight according to the traditional trees-down scenario.


Scansoriopteryx Epidendrosaurus Theropod Archosaur Daohugou Biota Jurassic 


Archosaurier aus dem Jura ist ein nicht-dinosaurischer Vogel Eine erneute Untersuchung mittels Keyence-3D-Digitalmikroskopie und Dunkelfeldbeleuchtung des fossilen Scansoriopteryx, eines zweifelhaften sperlingsgroßen prä-Archaeopteryx-Beleges aus den jurassischen Daohugou-Schichten, liefert neue Hinweise, welche die weithin anerkannte Hypothese in Frage stellen, dass Vögel von Dinosauriern abstammen und sich der Vogelflug über laufende Formen entwickelte. Im Widerspruch zu früheren Deutungen, die Scansoriopteryx als Coelurosaurier, also einen theropoden Dinosaurier, betrachteten, zeigt das Fehlen grundlegender Dinosaurier-Eigenschaften, dass er nicht von Dinosauriervorfahren abstammt und somit auch nicht als theropoder Dinosaurier angesehen werden sollte. Außerdem deuten die in Kombination mit stark abgeleiteten Merkmalen erhaltenen deutlich plesiomorphen Nichtdinosaurier-Eigenschaften bei gleichzeitig erst in Ansätzen vorhandenen vogelartigen Ausprägungen darauf hin, dass die tieferen Ursprünge der Aves außerhalb der Dinosaurier liegen und weiter zurück zu den basalen Archosauriern reichen. Abdrücke primitiver verlängerter Federn an den Vorder- und Hinterextremitäten legen nahe, dass Scansoriopteryx eine basale Form eines „Tetrapteryx“war, bei der beginnende Aerodynamik in Gestalt von Segel- oder Gleitflug möglich war. In Verbindung mit einzigartigen Anpassungen an eine baumbewohnende Lebensweise erfüllt Scansoriopteryx Vorhersagen aus dem frühen 20. Jahrhundert, die besagen, dass sich die Vorfahren der Vögel nicht aus Dinosauriern entwickelten, sondern stattdessen von früheren baumbewohnenden Archosauriern abstammen, bei denen sich der Flug gemäß der traditionellen Baumtheorie entwickelte.



The authors wish to thank Ji Qiang, for his valuable discussions and insights, the Institute of Geology, Chinese Academy of Geological Sciences; Nick J. Spruill, Senior Technologist and Alfred M. Pettinger, Senior Managing Consultant, Director of Mechanics, Engineering Systems Inc. for the Keyence microscopy; Sylvia J. Czerkas, Director of The Dinosaur Museum; and Frances James and other reviewers for their helpful comments.


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Copyright information

© Dt. Ornithologen-Gesellschaft e.V. 2014

Authors and Affiliations

  1. 1.The Dinosaur MuseumBlandingUSA
  2. 2.Department of BiologyUniversity of North CarolinaChapel HillUSA

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