Enantiornithes
| Enantiornithes | ||||||||
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Reconstruction of Iberomesornis in the |
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| Temporal occurrence | ||||||||
| Lower to Upper Crayon | ||||||||
| 130.7 to 66 million years | ||||||||
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| Systematics | ||||||||
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| Scientific name | ||||||||
| Enantiornithes | ||||||||
| Walker , 1981 |
The enantiornithes ("opposite birds", derived from Gr . Έναντα ( enanta ) "opposite, opposite" + όρνιθος ( ornithos ) " bird ") are a group of tooth-bearing fossil birds that died out at the end of the Cretaceous Period . After their first appearance in the Lower Cretaceous of Spain , Queensland and the northeast Chinese Jehol group , they were the most common and species-rich group of birds during the Upper Cretaceous .
anatomy
For the first time in 1981 by Cyril Alexander Walker described , the Enantiornithes differ in the articulation between the scapula and coracoid from the Ornithurae , which all modern birds belong: In contrast to the arrangement in ornithurinen birds is the shoulder blade a joint socket and the coracoid a pivot pin ago . In the carpometacarpus of the enantiornithes, the third metacarpal bone extended outward beyond the length of the second metacarpal bone.
Because of their toe proportions and long curved claws, many enantiornithine birds are considered tree dwellers. Some forms such as Eoenantiornis , Protopteryx and Eoalulavis had a thumb wing and were probably better fliers than primitive birds such as Archeopteryx , Jeholornis and Confuciusornis .
The fact that there was already extensive ecological diversification within the group in the Lower Cretaceous is shown among other things. a. the finds of Longipteryx, whose fore limb / hind limb ratio of 1.56 exceeded that of all other enantiornithes and whose beak and tooth morphology are interpreted as that of a fish eater, as well as Longirostravis , who presumably used its slender, pointed beak as a mud probe.
A special find was made known in June 2017: a foot and parts of the wing of a 99 million year old young animal were discovered in a piece of amber measuring just under eight centimeters in Burma . There is also another 127 million year old chick from Spain that was described in 2018. While the Asian specimen ( Elektorornis chenguangi ) is evidently a nest- fledger , the European fossil was described as a nest- seat .
Systematics
The following cladogram shows the relationships between Mesozoic bird groups according to Chiappe et al. (2002) with special consideration of the enantiornithes again:
| Aves ("Avialae" after Fastovsky and Weishampel 2005) |
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Genera (selection)
literature
- Chiappe, LM (2002): Basal bird phylogeny: problems and solutions. In: LM Chiappe and LM Witmer (Eds.): Mesozoic Birds: Above the Heads of Dinosaurs. 448-472. University of California Press, Berkeley.
- Chiappe, LM and Walker, CA (2002): Skeletal morphology and systematics of the Cretaceous Euenantiornithes (Ornithothoraces: Enantiornithes). In: LM Chiappe and LMWitmer (Eds.): Mesozoic Birds: Above the Heads of Dinosaurs. 240-267. University of California Press, Berkeley.
- Walker, C. (1981): New subclass of birds from the Cretaceous of South America. In: Nature. 252: 51-53. (Online)
- Zhonghe Zhou: The origin and early evolution of birds: discoveries, disputes, and perspectives from fossil evidence . In: Natural Sciences . 91, September 8, 2004, pp. 455-471. ISSN 0028-1042 , ISSN 1432-1904 . doi : 10.1007 / s00114-004-0570-4 .
Web links
Individual evidence
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↑ Fund 2017:
- Lida Xing et al .: A mid-Cretaceous enantiornithine (Aves) hatchling preserved in Burmese amber with unusual plumage ,
- in: Gondwana Research. Online advance publication of June 6, 2017, doi: 10.1016 / j.gr.2017.06.001
- Baby Bird from Time of Dinosaurs Found Fossilized in Amber. , on: news.nationalgeographic.com of June 7, 2017
- Extremely well-preserved chick from the era of the dinosaurs found in amber , on: www.nationalgeographic.de from November 9, 2017
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↑ Fund 2018:
- Fabien Knoll et al .: A diminutive perinate European Enantiornithes reveals an asynchronous ossification pattern in early birds ,
- in: Nature Communicationd 9, Article No .: 937 (2018) of March 5, 2018, doi: 10.1038 / s41467-018-03295-9
- Daniel Lingenhöhl: Tiny chick unearthed from the Cretaceous period , on Spektrum.de on March 5, 2018
- ↑ Lida Xing et al .: A New Enantiornithine Bird with Unusual Pedal Proportions Found in Amber . In: Current Biology . tape 29 , no. 14 , July 22, 2019, p. 2396–2401 , doi : 10.1016 / j.cub.2019.05.077 (English).