Gobipteryx

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Gobipteryx
Temporal range:
Ma
Eggs of Gobipteryx minuta
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Clade: Dinosauria
Clade: Saurischia
Clade: Theropoda
Clade: Avialae
Clade: Enantiornithes
Family: Gobipterygidae
Genus: Gobipteryx
Elżanowski, 1974
Species:
G. minuta
Binomial name
Gobipteryx minuta
Elżanowski, 1974
Synonyms

Gobipteryx (from Gobi [referring to the Gobi Desert where it was first discovered], and Greek pteryx "wing") is a

Period.[1] It is not known to have any direct descendants.[1] Like the rest of the enantiornithes clade, Gobipteryx is thought to have gone extinct near the end of the Cretaceous.[2]

Description

Based on a skull length of 45 millimeters, Gobipteryx has been estimated to be approximately the size of a partridge.[3] Its bones are fibrolamellar.[4]

The skull's general shape is gradually tapering toward the front.

choana is located below them, more rosteral than in most modern birds.[7] The nares are smaller than the antorbital fenestrae, a basal feature for ornithurae birds.[7] In addition, Gobipteryx's skull has an articulated rostrum.[7] The jaw hinge is associated with the articulation of the quadrate with the pterygoid processes.[1] The articular region of the mandible contains internal and retroarticular processes and has uniform symphysis.[1] This animal has a large, uniform, and sutureless braincase.[1]

The

neural spines of the twelfth and thirteenth vertebrae form the nuchal blade, which represents the point of greatest elevation in the vertebral column.[8]

The

coracoids are slightly concave anteriorly and are separate from the scapulae dorsally. They also stick out from the neck on either side.[8] Gobipteryx's clavicles curve in a way that is consistent with that of other birds.[8]

The

Metacarpals II and III have been found in embryonic fossils and are observed to be about equal size and are in close contact with each other.[8]

Paleobiology

Flight

Gobipteryx is believed to have been capable of flight.[4][8] The scapula is long, and therefore, well suited for flight by having more area for muscle attachment.[8] In addition, the forelimb of Gobipteryx is more than twice the length of the thorax, falling within the acceptable range observed in flying birds.[8]

Development

Gobipteryx, along with other enantiornithes, is thought to have

superprecocial development, in which it was capable of flying upon hatching.[4][8] Evidence for this comes from the fact that the forelimbs and shoulders of advanced embryos are almost completely ossified.[8] In addition, the growth of G. minuta has been shown to slow down immediately following hatching.[4] This suggests that it was highly mobile in its life, since locomotion has been shown to slow the growth of young birds by focusing energy and resources elsewhere.[4] This onset of flight so early in life is not seen in most modern birds, which begin flying when they have reached or are close to full size.[4]

History

The first specimens were two damaged skulls discovered as part of the 1971 Polish-Mongolian Paleontological Expedition to the Gobi Desert by Dr. Teresa Maryańska,[1] however, at the time, it was not immediately recognized that both of these skulls belonged to Gobipteryx.[3][6] It was first found in the sandstones of the Lower Nemegt Beds of the Barun Goyot Formation of the Nemegt Basin.[1] The holotype specimen is housed at the Institute of Paleobiology of the Polish Academy of Sciences[8] in Warsaw, Poland and was first described by Dr. Andrzej Elżanowski using a single damaged skull.[1] Initially, Gobipteryx was classified as a member of the clade Palaeognathae on the basis of its jaw and palate.[1] However, in 1981, Dr. Cyril Walker defined the clade enantiornithes[9] and Gobipteryx was reclassified as an enantiornithes bird.

In 1996,

dentary bones of the skull.[7]

In 1994, an expedition to the Gobi Desert was conducted by the American Museum of Natural History and the Mongolian Academy of Sciences, where a well preserved Gobiptetyx minuta skull was found in the Nemegt Basin.[7] This new specimen provided further evidence for the placement of Gobipteryx into enantiornithes.[7] In addition, it allowed for the reconstruction of the palate, which was poorly understood in Mesozoic birds.[7]

Also during the 1971 Polish-Mongolian Paleontological Expedition to the Gobi Desert, in which the first specimens were found, advanced

postcranial fossils of G. minuta found.[8]

See also

References

  1. ^ a b c d e f g h i j k l m Elżanowski, A. (1974): "Preliminary note on the Palaeognthous bird from the Upper Cretaceous of Mongolia" Palaeontologia Polonica 30:103-109, plates 32-33.
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  6. ^ a b Elżanowski, A. (1977): "Skulls of Gobipteryx (Aves) from the Upper Cretaceous of Mongolia" Palaeontologia Polonica 37: 153-166.
  7. ^ a b c d e f g h Chiappe, Luis M.; Norell, Mark and Clark, James (2001): "A New Skull of Gobipteryx minuta (Aves: Enantiornithes) from the Cretaceous of the Gobi Desert". American Museum Novitates 3346: 1–15.
  8. ^ a b c d e f g h i j k l m n o p q Elżanowski, A. (1981): "Embryonic Bird Skeletons from the Late Cretaceous of Mongolia". Palaeontologica Polonica 42: 147-179.
  9. ^ Kurochkin, E. (1996): A new enantiornithid of the Mongolian Late Cretaceous, and the general appraisal of the Infraclass Enantiornithes (Aves). Russian Academy of Sciences, Palaeontological Institute, Special Issue: 1-50.