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An enigmatic plant-eating theropod from the Late Jurassic period of Chile

Nature volume 522, pages 331334 (18 June 2015) | Download Citation


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Theropod dinosaurs were the dominant predators in most Mesozoic era terrestrial ecosystems1. Early theropod evolution is currently interpreted as the diversification of various carnivorous and cursorial taxa, whereas the acquisition of herbivorism, together with the secondary loss of cursorial adaptations, occurred much later among advanced coelurosaurian theropods1,2. A new, bizarre herbivorous basal tetanuran from the Upper Jurassic of Chile challenges this conception. The new dinosaur was discovered at Aysén, a fossil locality in the Upper Jurassic Toqui Formation of southern Chile (General Carrera Lake)3,4. The site yielded abundant and exquisitely preserved three-dimensional skeletons of small archosaurs. Several articulated individuals of Chilesaurus at different ontogenetic stages have been collected, as well as less abundant basal crocodyliforms, and fragmentary remains of sauropod dinosaurs (diplodocids and titanosaurians).

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  • 17 June 2015

    Minor changes were made to author affiliations.


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We thank P. Barrett, A. Milner and R. Butler for comments on early versions of this manuscript. We are grateful to C. Alsina, M. Milani, R. Stoll and M. Aranciaga for field assistance and technical preparation of Chilesaurus specimens. G. Lio executed the silhouette of Chilesaurus in Fig. 1. C. Burke offered support to conduct fieldwork and technical preparation of the specimens. We are indebted to the Agencia Nacional de Promoción Científica y Tecnológica (PICT 2010-066 to F.E.N.) and the Fondo Nacional de Desarrollo Científico y Tecnológico (no. 1121140 and 1030162 to M.S.) for continuing financial assistance.

Author information


  1. Conicet, Museo Argentino de Ciencias Naturales “B. Rivadavia”, Av. Ángel Gallardo 470 (C1405DJR), Buenos Aires, Argentina

    • Fernando E. Novas
    • , Leonardo Salgado
    •  & Marcelo P. Isasi
  2. Museo Argentino de Ciencias Naturales “B. Rivadavia”, Av. Ángel Gallardo 470 (C1405DJR), Buenos Aires, Argentina

    • Fernando E. Novas
    • , Federico L. Agnolín
    • , Nicolás R. Chimento
    •  & Marcelo P. Isasi
  3. Conicet, Instituto de Investigación en Paleobiología y Geología, Universidad Nacional de Río Negro, General Roca 1242, General Roca (8332), Río Negro, Argentina

    • Leonardo Salgado
  4. Instituto de Investigación en Paleobiología y Geología, Universidad Nacional de Río Negro, General Roca 1242, General Roca (8332), Río Negro, Argentina

    • Leonardo Salgado
  5. Universidad Andres Bello, Geología, Facultad de Ingeniería, Sazie 2315, Santiago, Chile

    • Manuel Suárez
  6. Fundación de Historia Natural Félix de Azara, Universidad Maimónides, Hidalgo 775(C1405BDB), Buenos Aires, Argentina

    • Federico L. Agnolín
  7. School of Geography, Earth and Environmental Sciences, University of Birmingham, Birmingham B15 2TT, UK

    • Martín D. Ezcurra
  8. Servicio Nacional de Geología y Minería, Avenida Santa María 0104, Santiago 8330177, Chile

    • Rita de la Cruz
  9. Red Paleontológica U-Chile. Laboratorio de Ontogenia y Filogenia, Departamento de Biología, Facultad de Ciencias, Universidad de Chile, Santiago 7800003, Chile

    • Alexander O. Vargas
    •  & David Rubilar-Rogers
  10. Área Paleontología, Museo Nacional de Historia Natural de Chile, casilla 787, Santiago, Chile

    • David Rubilar-Rogers


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F.E.N., L.S., M.S., F.L.A., M.D.E., N.R.C., A.O.V. and D.R.-R. designed the study, collected data, performed the comparative and analytical work, and wrote the paper. R.d.l.C. and M.P.I. collected data and contributed to the writing and discussion.

Competing interests

The authors declare no competing financial interests.

Corresponding author

Correspondence to Fernando E. Novas.

Data have been deposited in ZooBank under Life Science Identifier (LSID) http://zoobank.org/urn:lsid:zoobank.org:act:7B6DE8C7-C78D-48C0-B818-65C454AEFB58.

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    Supplementary Information

    This file contains Supplementary Text and Data, Supplementary Figures and additional references, which are divided into the following sections: Occurrence, age, and preservation of the holotype and referred specimens of Chilesaurus diegosuarezi gen. et sp. nov.; Phylogenetic analyses; and Morphospace analysis.

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