Gansus

Quality 0.50 · 2 views · Updated 2 months ago

Extinct genus of dinosaurs

title: "Gansus" type: doc version: 1 created: 2026-02-28 author: "Wikipedia contributors" status: active scope: public tags: ["gansuidae", "bird-genera", "aptian-birds", "fossil-taxa-described-in-1984", "birds-of-asia", "aquatic-birds"] description: "Extinct genus of dinosaurs" topic_path: "general/gansuidae" source: "https://en.wikipedia.org/wiki/Gansus" license: "CC BY-SA 4.0" wikipedia_page_id: 0 wikipedia_revision_id: 0

::summary Extinct genus of dinosaurs ::

| fossil_range = Early Cretaceous, | image = 甘肃鸟化石.jpg | image_caption = Fossil specimen of G. yumenensis, the Gansu Provincial Museum. | type_species = Gansus yumenensis | type_species_authority = Hou & Liu, 1984 | taxon = Gansus | authority = Hou & Liu, 1984 | subdivision_ranks = Other species | subdivision = * Gansus zheni? Liu et al., 2014

Gansus is a genus of aquatic avialans that lived during the Aptian age of the Early Cretaceous (Aptian-Albian) period in what are now Gansu and Liaoning provinces, western China. The rock layers from which their fossils have been recovered are dated to 120 million years ago. It was first described in 1984 on the basis of an isolated left leg. It is the oldest-known member of the Ornithurae, the group which includes modern birds (Neornithes) and extinct related groups, such as Ichthyornis and Hesperornithes.

Description

::figure[src="https://upload.wikimedia.org/wikipedia/commons/1/13/Gansus_NNHM.jpg" caption="Fossil specimen of ''G. zheni'', which is sometimes considered as a synonym of ''Iteravis'', in the [[Beijing Museum of Natural History]]."] ::

::figure[src="https://upload.wikimedia.org/wikipedia/commons/8/80/Gansus_melanosomes.png" caption="Images showing the presence of [[melanosomes]] in ''Gansus'' and extant (C, D) feathersBarden, H.E. ''et al.'' (2011) Morphological and Geochemical Evidence of Eumelanin Preservation in the Feathers of the Early Cretaceous Bird, ''Gansus yumenensis''. ''PLoS ONE'' 6(10):e25494."] ::

The genus Gansus originally contained a single species, G. yumenensis. In 2014, new species G. zheni is described, but some researchers consider this species to be a synonym of Iteravis huchzermeyeri. It was about the size of a pigeon and similar in appearance to loons and diving ducks. It had many features common among modern birds, and also retained some basal traits such as its clawed wings.

Gansus was discovered in the form of a single fossil foot in 1981. Five more well-preserved fossils were found in 2003–2004 in mudstone at the site of an ancient lake at Changma, Gansu; the geological stratum in which the fossils were found is the Xiagou Formation. Their bodies had settled in anoxic mud and were soon covered with further extremely fine silty sediments. Without oxygen, their remains resisted decay: these specimens preserved remains of flight feathers and traces of the webbing between their toes.

You et al. (2006) concluded that the anatomical characteristics of Gansus were similar to foot-propelled diving birds, such as Hesperornis (from the Cretaceous) and the loons (Gaviidae) and grebes (Podicipedidae).

Classification

::figure[src="https://upload.wikimedia.org/wikipedia/commons/b/b9/Gansus-Paleozoological_Museum_of_China.jpg" caption="Holotype foot, [[Paleozoological Museum of China"] ::

Gansus was described as the oldest known ornithuran. The Ornithurae, however, has been given several very different definitions. In the definition used by You and colleagues (that is, the clade containing all living birds plus Hesperornis and Ichthyornis), Gansus is indeed the oldest known member. However, several birds from the older Yixian Formation and contemporary Jiufotang Formation are considered ornithurans under other definitions. Under any definition, all living birds, including taxa as diverse as ostriches, hummingbirds and eagles, are descended from basal ornithurans, many of which were semi-aquatic. It is now thought possible that all modern birds descended specifically from a semi-aquatic bird similar to Gansus. Thus, while Gansus is not necessarily a direct ancestor of today's birds, it is closely related to such an ancestral species.

References

References

  1. (2014-11-14). "An advanced, new long-legged bird from the Early Cretaceous of the Jehol Group (northeastern China): insights into the temporal divergence of modern birds". [[Zootaxa]].
  2. Ji, S.-A. Atterholt, J. O'Connor, J.K. Lamanna, M.C. Harris, J.D. Li, D.-Q. You, H.-L. & Dodson, P. (2011) [http://onlinelibrary.wiley.com/doi/10.1111/j.1096-3642.2010.00671.x/abstract A new, three-dimensionally preserved enantiornithine bird (Aves: Ornithothoraces) from Gansu Province, north-western China]. ''Zoological Journal of the Linnean Society'' 162(1):201–219.
  3. Hou, L. & Liu, Z. (1984) A new fossil bird from Lower Cretaceous of Gansu and early evolution of birds. ''Sci. Sin. Ser. B.'' 27:1296−1302.
  4. O’Connor, J.K & Zhou, Z. (2012) [http://www.tandfonline.com/doi/abs/10.1080/14772019.2012.690455 A redescription of ''Chaoyangia beishanensis'' (Aves) and a comprehensive phylogeny of Mesozoic birds]. ''Journal of Systematic Palaeontology''.
  5. Barden, H.E. ''et al.'' (2011) Morphological and Geochemical Evidence of Eumelanin Preservation in the Feathers of the Early Cretaceous Bird, ''Gansus yumenensis''. ''PLoS ONE'' 6(10):e25494.
  6. Ju, Shu-bin. (2021-06-01). "A reassessment of Iteravis huchzermeyeri and Gansus zheni from the Jehol Biota in western Liaoning, China". China Geology.
  7. You, H.-L. Lamanna, M.C. Harris, J.D. Chiappe, L.M. O'Connor, J.K. Ji, S.-A. Lu, J.-C. Yuan, C.-X. Li, D.-G. Zhang, X. Lacovara, K.J. Dodson, P. & Ji, Q. (2006) [https://www.science.org/doi/10.1126/science.1126377 A Nearly Modern Amphibious Bird from the Early Cretaceous of Northwestern China]. ''Science'' 312:1640-1643.
  8. In 2011, there were described nine additional specimens, that supported on the basis of a statistic analysis of the sternum and elements of the legs, the hypothesis that ''Gansus'' was a volant bird.Li, Y. Zhang, Y.-G. Zhou, Z.-H. Li, Z.-H. Liu, D. & Wang, X.-L. (2011) New material of ''Gansus'' and a discussion on its habit. ''Vert. PalAs'' 49:435–445.

::callout[type=info title="Wikipedia Source"] This article was imported from Wikipedia and is available under the Creative Commons Attribution-ShareAlike 4.0 License. Content has been adapted to SurfDoc format. Original contributors can be found on the article history page. ::

gansuidaebird-generaaptian-birdsfossil-taxa-described-in-1984birds-of-asiaaquatic-birds