Longipteryx

File:Life reconstruction of Longipteryx.png

Excluding the tail, Longipteryx was some 15 cm long overall in life. It had a long bill — longer than the rest of the head — with a few hooked teeth at the tip, and, as the name implies, proportionally long and strong wings. Although it was basal to the extent that it had two long separate fingers with claws and a stubby thumb, the flight apparatus was generally quite well developed, and unlike most other birds of its time it possessed uncinate processes which strengthened the ribcage. Its claws and toes were long and strong while the leg was quite short. Altogether, the ability to fly and to perch was quite sophisticated for its age, to the detriment of terrestrial locomotion: the humerus was 1.56 times the length of the femur.{{cite journal |first1=Matthew C. |last1=Lamanna |first2=Hai-Lu |last2=You |first3=Jerald D. |last3=Harris |first4=Luis M. |last4=Chiappe |first5=Shu-An |last5=Ji |first6=Jun-Chang |last6=Lü |first7=Qiang |last7=Ji |title=A partial skeleton of an enantiornithine bird from the Early Cretaceous of northwestern China |journal=Acta Palaeontologica Polonica |volume=51 |issue=3 |year=2006 |pages=423–434 |url=https://www.app.pan.pl/article/item/app51-423.html }}

The holotype retains many feather impressions, though poorly preserved; remiges do not seem to have been preserved, and what feathers remain are apparently only body feathers, wing coverts and down. The end of the tail is destroyed in the holotype; no rectrices are preserved and while the pygostyle is complete in other skeletons, only halos of short feathers are preserved. While the related Shanweiniao and some other enantiornithines preserve two, four, or eight long display feathers on the tail, the absence of such feathers in any known specimen of Longipteryx probably indicates that they were absent in this species.{{cite journal | last1 = O'Connor | first1 = J.K. | last2 = Zhou | first2 = Z. | last3 = Zhang | first3 = F. | year = 2011| title = A reappraisal of Boluochia zhengi (Aves: Enantiornithes) and a discussion of intraclade diversity in the Jehol avifauna, China | journal = Journal of Systematic Palaeontology | volume = 9| issue = 1 | pages = 51–63| doi = 10.1080/14772019.2010.512614 | bibcode = 2011JSPal...9...51O | s2cid = 84817636 }}

Longipteryx was frugivorous, indicated by the discovery of complete gymnosperm seeds and a lack of gastroliths within two specimens, STM8–86 and STM8–112.{{cite journal|author1=O’Connor, J.|author2=Clark, A.|author3=Herrera, F.|author4=Yang, X.|author5=Wang, X.|author6=Zheng, X.|author7=Hu, H.|author8=Zhou, Z.|year=2024|title=Direct evidence of frugivory in the Mesozoic bird Longipteryx contradicts morphological proxies for diet|journal=Current Biology|doi=10.1016/j.cub.2024.08.012}} Initially, it was interpreted as a piscivore or an insectivore.{{cite journal |last1=Zhou |first1=Ya-Chun |last2=Sullivan |first2=Corwin |last3=Zhou |first3=Zhong-He |last4=Zhang |first4=Fu-Cheng |title=Evolution of tooth crown shape in Mesozoic birds, and its adaptive significance with respect to diet |journal=Palaeoworld |date=January 2021 |volume=30 |issue=4 |pages=724–736 |doi=10.1016/j.palwor.2020.12.008 |s2cid=234117375 }}{{cite journal | doi=10.1186/s12915-022-01294-3 | title=Diet of Mesozoic toothed birds (Longipterygidae) inferred from quantitative analysis of extant avian diet proxies | year=2022 | last1=Miller | first1=Case Vincent | last2=Pittman | first2=Michael | last3=Wang | first3=Xiaoli | last4=Zheng | first4=Xiaoting | last5=Bright | first5=Jen A. | journal=BMC Biology | volume=20 | issue=1 | page=101 | pmid=35550084 | pmc=9097364 | doi-access=free }} The authors of the 2024 study who reported direct evidence of frugivory in Longipteryx suggested that researchers should be cautious when predicting the diets in extinct taxa based on "untested morphological proxies".

File:Longipteryx chaoyangensis 2.JPG]]

The affiliations of Longipteryx are not resolved. While it has been sometimes included in the Enantiornithes{{cite journal |last1=Enpu |first1=Gong |last2=Lianhai |first2=Hou |last3=Lixia |first3=Wang |title=Enantiornithine Bird with Diapsidian Skull and Its Dental Development in the Early Cretaceous in Liaoning, China |journal=Acta Geologica Sinica |date=February 2004 |volume=78 |issue=1 |pages=1–7 |doi=10.1111/j.1755-6724.2004.tb00668.x |bibcode=2004AcGlS..78....1G |s2cid=129218847 }} and groups specifically with Euenantiornithes in some cladistic analyses,{{cite web |last1=Mortimer |first1=Michael |work=The Theropod Database |archive-url=https://web.archive.org/web/20130516175802/http://archosaur.us/theropoddatabase/Phylogeny%20of%20Taxa.html |title=Phylogeny of taxa |url=http://archosaur.us/theropoddatabase/Phylogeny%20of%20Taxa.html |archive-date=16 May 2013 }}{{self-published inline|date=August 2021}} it might be basal to or in Enantiornithes, being somewhat reminiscent of the equally puzzling Protopteryx.{{cite mailing list |last1=Mortimer |first1=Michael |date=21 February 2004 |url=http://dml.cmnh.org/2004Feb/msg00422.html |title=Tyrannosauroids and dromaeosaurs |mailing-list=Dinosaur Mailing List |archive-url=https://web.archive.org/web/20040729131502/http://dml.cmnh.org/2004Feb/msg00422.html |archive-date=29 July 2004 }}{{self-published inline|date=August 2021}} Its plesiomorphies are comprehensive, as can be expected from its old age, but the autapomorphies appear quite "modern", especially compared to other early Enantiornithes.

A distinct order (Longipterygiformes) and family (Longipterygidae) has been proposed for it. Given that neither its exact relationships nor any close relatives are presently known, not much can be said about the phylogenetic position of L. chaoyangensis. On the other hand, Longirostravis hani, described a few years after Longipteryx, appears to be phylogenetically closer to the present taxon than other Mesozoic birds and indeed they might constitute a clade of early specialized Euenantiornithes. If this is correct, they might well be considered as an order, in which case Longirostravisiformes and Longirostravisidae would become junior synonyms of Longipterygiformes and Longipterygidae, respectively.

{{Reflist}}

• {{cite journal |last1=Clarke |first1=Julia A. |last2=Zhou |first2=Zhonghe |last3=Zhang |first3=Fucheng |title=Insight into the evolution of avian flight from a new clade of Early Cretaceous ornithurines from China and the morphology of Yixianornis grabaui |journal=Journal of Anatomy |date=March 2006 |volume=208 |issue=3 |pages=287–308 |doi=10.1111/j.1469-7580.2006.00534.x |pmid=16533313 |pmc=2100246 }}

• {{cite web |archive-url=https://web.archive.org/web/20070822114227/http://www.shanghai-fossil.com.cn/products/display.asp?ClassID=3&ProductsID=291 |title=朝阳长翼鸟 |trans-title=Chaoyang Longwing Bird |language=Chinese |url=http://www.shanghai-fossil.com.cn/products/display.asp?ClassID=3&ProductsID=291 |archive-date=22 August 2007 }}

{{Portal|Paleontology}}

{{Enantiornithes}}

{{Taxonbar|from=Q1869545}}

Category:Bird genera

Category:Early Cretaceous birds of Asia

Category:Fossil taxa described in 2001

Category:Jiufotang fauna

Category:Longipterygidae