Paraprotopteryx

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Paraprotopteryx
Temporal range:
Ma
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Clade: Dinosauria
Clade: Saurischia
Clade: Theropoda
Clade: Avialae
Clade: Enantiornithes
Genus: Paraprotopteryx
Zheng, Zhang & Hou, 2007
Species:
P. gracilis
Binomial name
Paraprotopteryx gracilis
Zheng, Zhang & Hou, 2007

Paraprotopteryx is a genus of

enantiornithean birds from the Mesozoic of China.[1]

In 2007, the type species Paraprotopeteryx gracilis was named and described by Zheng Xiaoting, Zhang Zihui and Hou Lianhai. The generic name means "near Protopteryx", in reference to a presumed similarity with that genus. The specific name is intended to mean "pretty".[1]

The holotype is specimen STM V001. It consists of a skeleton with skull on a plate and counterplate. The investigation preceding the description of the species proved that fossil traders had added the skull of a different individual to the torso. The description is based on the rump parts. Feathers have been preserved. The rump represents a subadult individual.[1]

Though initially reported to be from the

Hebei Province, China, and is therefore of uncertain age. While much of the Huajiying Formation underlies the Yixian Formation,[2] Ji and colleagues suggested in 2008 that the Qiaotou Member correlates with the Dawangzhangzi beds of the Yixian Formation, dated to approximately 122 million years ago by Zhou Zhonghe in 2006.[3]

Distinguishing characteristics

The original description suggested a number of distinguishing traits. Paraprotopteryx would have had a

Enantiornithines. The carpometacarpus is only partially fused.[1]

Paraprotopteryx has four, ten centimetres long,

rectrices (flight feathers on the tail), more than doubling the total body length, which may represent an important step in feather evolution. They have a very elongated ribbon-like shaft and only the tips are barbed and expanded. In Paraprotopteryx they may have served as a secondary sex characteristic. This was the first time a tail fan was reported for Enantiornithes. Later such a double pair was reported for Shanweiniao. However, although the presence of two ribbon-like rectrices is certain (as in the related enantiornithean bird Protopteryx) the describers of Shanweiniao in 2012 voiced a suspicion that the second pair of rectrices in Paraprotopteryx might be the result of artifice.[4]

References

  1. ^ a b c d Zheng, X. Zhang, Z. & Hou, L. (2007) A new enantiornithine bird with four long rectrices from the Early Cretaceous of northern Hebei, China. Acta Geologica Sinica 81(5):703-708.
  2. ^ Jin, Zhang, Li, Zhang, Li and Zhou (2008). "On the horizon of Protopteryx and the early vertebrate fossil assemblages of the Jehol Biota." Chinese Science Bulletin, 53(18): 2820-2827.
  3. ^ Zhou, Z. (2006). "Evolutionary radiation of the Jehol Biota: chronological and ecological perspectives." Geological Journal, 41: 377–393.
  4. ^ Jingmai K. O’Connor, Luis M. Chiappe, Cheng-ming Chuong, David J. Bottjer and Hailu You (2012) "Homology and Potential Cellular and Molecular Mechanisms for the Development of Unique Feather Morphologies in Early Birds." Geosciences, 2 157-177.

External links