Temporal range:
Early CretaceousPresent, 131–0 Ma
Fossil of an enantiornithean (Junornis houi)
Southern Ground Hornbill.JPG
Southern ground hornbill (Bucorvus leadbeateri)
Scientific classification e
Chiappe & Calvo, 1994

Ornithothoraces is a group of avialans that includes all enantiornithes ("opposite birds") and the euornithes ("true birds"), which includes modern birds and their closest ancestors. The name Ornithothoraces means "bird thoraxes". This refers to the modern, highly advanced anatomy of the thorax that gave the ornithothoracines superior flight capability compared with more primitive avialans. This anatomy includes a large, keeled breastbone, elongated coracoids and a modified glenoid joint in the shoulder, and a semi-rigid rib cage. In spite of this at least the sternum seems to have developed convergently rather than being a true homology.[1]

The earliest known members of the group are the enantiornitheans Protopteryx fengningensis, Eopengornis martini, and Cruralispennia multidonta, as well as the euornithine Archaeornithura meemannae, all from the Sichakou Member of the Huajiying Formation in China, which has been dated to 130.7 million years old.[2] At least one other enantiornithean, Noguerornis gonzalezi, may be even older, at up to 145.5 million years ago, though its exact age is uncertain.[3]


In 1994, Chiappe and Calvo established a phylogenetic definition of the group. They defend Ornithothoraces as a node-based clade, the common ancestor of Iberomesornis romerali and modern birds, and all of its other descendants.[4] In 1998, Paul Sereno defined Ornithothoraces in the same way, but used Sinornis santensis instead of Iberomesornis romerali.[5]

The cladogram below follows the results of a phylogenetic analysis by Wang et al., 2016:[6]





























  1. ^ Zheng, Xiaoting; Wang, Xiaoli; O'Connor, Jingmai; Zhou, Zhonghe (9 October 2012). "Insight into the early evolution of the avian sternum from juvenile enantiornithines". Nature Communications. 3 (1): 1116. Bibcode:2012NatCo...3.1116Z. doi:10.1038/ncomms2104. PMID 23047674.
  2. ^ Wang, M.; Zheng, X.; o’Connor, J. K.; Lloyd, G. T.; Wang, X.; Wang, Y.; Zhang, X.; Zhou, Z. (2015). "The oldest record of ornithuromorpha from the early cretaceous of China". Nature Communications. 6: 6987. Bibcode:2015NatCo...6.6987W. doi:10.1038/ncomms7987. PMC 5426517. PMID 25942493.
  3. ^ Holtz, Thomas R. Jr. (2012) Dinosaurs: The Most Complete, Up-to-Date Encyclopedia for Dinosaur Lovers of All Ages, Winter 2011 Appendix.
  4. ^ Chiappe, Luis; Calvo, J.O. (1994). "Nequenornis volans, a new Late Cretaceous bird (Enantiornithes:Avisauridae) from Patagonia, Argentina". Journal of Vertebrate Paleontology. 14 (2): 230–246. doi:10.1080/02724634.1994.10011554.
  5. ^ Sereno, Paul (1998). "A rationale for phylogenetic definitions, with application to the higher-level taxonomy of Dinosauria". Neues Jahrbuch für Geologie und Paläontologie. 210: 41–83. doi:10.1127/njgpa/210/1998/41.
  6. ^ Wang, Min; Wang, Xiaoli; Wang, Yan; Zhou, Zhonghe (25 January 2016). "A new basal bird from China with implications for morphological diversity in early birds". Scientific Reports. 6 (1): 19700. Bibcode:2016NatSR...619700W. doi:10.1038/srep19700. PMC 4726217. PMID 26806355.

Media files used on this page

Author/Creator: GabrielNU, Licence: CC BY-SA 4.0
Reconstruction of Patagonykus puertai. Based on Novas (1997); missing portions follow typical alvarezsaurid proportions (e.g. Shuvuuia)
Mononykus Restoration.png
Author/Creator: PaleoNeolitic, Licence: CC BY 4.0
Life restoration of the Mongolian alvarezsaurid Mononykus olecranus.
Therizinosaurus Restoration.png
Author/Creator: PaleoNeolitic, Licence: CC BY 4.0
Life restoration of the gigantic, Late Cretaceous therizinosaurid Therizinosaurus cheloniformis. Claws and arms based on holotype PIN 551-483 and specimens IGM 100/15, 100/16 and 100/17.
Apatoraptor NT small.jpg
Author/Creator: Nobu Tamura email:nobu.tamura@yahoo.com http://spinops.blogspot.com/ http://paleoexhibit.blogspot.com/, Licence: CC BY-SA 4.0
Apatoraptor pennatus
Ambopteryx restoration.png
Author/Creator: Audrey.m.horn, Licence: CC BY-SA 4.0
Restoration of Ambopteryx longibrachium based on known fossil elements
Anchiornis martyniuk.png
Author/Creator: Matt Martyniuk, Licence: CC BY 3.0
Illustration of the basal troodontid Anchiornis huxleyi, by Matt Martyniuk. Digital. Colors based on the patterns recovered by Li et al. 2010.
Microraptor Restoration (cropped).png
Author/Creator: Fred Wierum, Licence: CC BY-SA 4.0
Microraptor gui reconstruction cropped for use in navboxes, etc.
Utahraptor Restoration.png
Author/Creator: Fred Wierum, Licence: CC BY-SA 4.0
Artistic restoration of Utahraptor ostrommaysorum
(c) FunkMonk, CC BY 3.0
Zanabazar junior (formerly Saurornithoides).
Austroraptor Restoration.png
Author/Creator: Fred Wierum, Licence: CC BY-SA 4.0
Artistic restoration of Austroraptor cabazai
Archaeopteryx lithographica - Pedro José Salas Fontelles (flipped).jpg
Author/Creator: Pedro José Salas Fontelles, Licence: CC BY-SA 3.0
Restauración del aspecto en vida del dinosaurio transicional Archaeopteryx lithographica que habitó en el Jurásico tardío, hace unos 150 millones de años, en lo que hoy es el sur de Alemania. Está realizado a partir del esqueletal realizado por el paleontólogo Scott Hartman.


Éste fósil tiene una importancia vital en el estudio de las aves y su evolución a partir de los dinosaurios, así como la aparición del vuelo en estos animales.

La ilustración representa la coloración que se le atribuye a Archaeopteryx gracias al estudio de los melanosomas. Se sabe que predominaba una coloración oscura o negruzca en todo el animal con las puntas de las plumas de vuelo de color más oscuro que el resto del cuerpo. Me he inspirado en el plumaje del Cormorán grande Phalacrocorax carbo.
Confuciusornis plumage pattern.jpg
Author/Creator: Art by Velizar Simeonovski. Published by Quanguo Li​, Julia A. Clarke, Ke-Qin Gao, Jennifer A. Peteya, Matthew D. Shawkey, Licence: CC BY 4.0

Reconstruction of the plumage in Confuciusornis CUGB P140.

Morphological data and probable eumelanin signatures are consistent darker preserved regions as associated with dark colors in the fossil (sampling regime explained in Fig. 1).
Longipteryx restoration.jpg
Author/Creator: El fosilmaníaco, Licence: CC BY-SA 4.0
Life restoration of Longipteryx chaoyangensis, an enantiornithine bird which lived in China during the Early Cretaceous period, around 120 million years ago
Cruralispennia reconstruction.tif
Author/Creator: Fanboyphilosopher (Neil Pezzoni), Licence: CC BY-SA 4.0
A life reconstruction of the enantiornithean Cruralispennia multidonta.
Patagopteryx deferrariisi.jpg
Author/Creator: FunkMonk (Michael B. H.), Licence: CC BY-SA 3.0
Patagopteryx deferrariisi
Ichthyornis restoration.jpeg
Author/Creator: El fosilmaníaco, Licence: CC BY-SA 4.0
Life restoration of Ichthyornis dispar, a primitive seabird that lived in the Western Interior Seaway (North America)during the Late Cretaceous.
Author/Creator: Di Liu, Luis M. Chiappe, Francisco Serrano, Michael Habib, Yuguang Zhang, Qinjing Meng, Licence: CC BY 2.5
Slab (BMNHC-PH 919a) (A) and counterslab (BMNHC-PH 919b) (B) of Junornis houi.
Southern Ground Hornbill.JPG
Author/Creator: D. Gordon E. Robertson, Licence: CC BY-SA 3.0
Southern Ground Hornbill (Bucorvus leadbeateri), Kruger Park, South Africa