Editing Bird (section)

===Dinosaurs and the origin of birds===
{{Main|Origin of birds}}
{{Cladogram|caption=Cladogram following the results of a phylogenetic study by Cau ''et al.'', 2015<ref name=cauetal2015>{{cite journal|doi=10.7717/peerj.1032|pmid=26157616|pmc=4476167|title=The phylogenetic affinities of the bizarre Late Cretaceous Romanian theropod ''Balaur'' bondoc(Dinosauria, Maniraptora): Dromaeosaurid or flightless bird?|journal=PeerJ|volume=3|pages=e1032|year=2015|last1=Cau|first1=Andrea|last2=Brougham|first2=Tom|last3=Naish |first3=Darren |doi-access=free }}</ref> |clades=
{{clade| style=font-size:75%;line-height:80%
|label1=[[Paraves]]
|1={{clade
  |1={{extinct}}[[Scansoriopterygidae]]
  |2={{clade
    |1={{extinct}}''[[Eosinopteryx]]''
    |label2=[[Eumaniraptora]]
    |2={{clade
     |1=†''[[Jinfengopteryx]]''
     |2=†''[[Aurornis]]''
     |3=†[[Dromaeosauridae]]
     |4=†[[Troodontidae]]
     |5=[[Avialae]] }} }} }} }} }}
[[File:Birds and dinosaurs.webp|left|thumb|upright=1.35|Simplified [[phylogenetic tree]] showing the relationship between modern birds and other dinosaurs<ref>{{Cite journal|last1=Plotnick|first1=Roy E.|last2=Theodor|first2=Jessica M. |last3=Holtz|first3=Thomas R.|date=24 September 2015|title=Jurassic Pork: What Could a Jewish Time Traveler Eat?|journal=Evolution: Education and Outreach|volume=8|issue=1|pages=17 |doi=10.1186/s12052-015-0047-2 |doi-access=free|hdl=1903/27622|hdl-access=free}}</ref>]]

Based on fossil and biological evidence, most scientists accept that birds are a specialised subgroup of [[theropod]] [[dinosaur]]s<ref>{{Cite journal|last=Prum|first=Richard O. |title=Who's Your Daddy?|journal=Science|volume=322|pages=1799–1800|date=19 December 2008|doi=10.1126/science.1168808|pmid=19095929|issue=5909 |doi-access=free}}</ref> and, more specifically, members of [[Maniraptora]], a group of theropods which includes [[Dromaeosauridae|dromaeosaurids]] and [[Oviraptorosauria|oviraptorosaurs]], among others.<ref>{{Cite book|last=Paul |first=Gregory S. |author-link=Gregory S. Paul |chapter=Looking for the True Bird Ancestor |year=2002 |title=Dinosaurs of the Air: The Evolution and Loss of Flight in Dinosaurs and Birds |url=https://archive.org/details/dinosaursofairev0000paul |location=Baltimore|publisher=Johns Hopkins University Press |isbn=0-8018-6763-0|pages=[https://archive.org/details/dinosaursofairev0000paul/page/171 171]–224}}</ref> As scientists have discovered more theropods closely related to birds, the previously clear distinction between non-birds and birds has become blurred. By the 2000s, discoveries in the [[Liaoning]] Province of northeast China, which demonstrated many small theropod [[feathered dinosaur]]s, contributed to this ambiguity.<ref>{{Cite book |last=Norell |first=Mark |author2=Mick Ellison |year=2005 |title=Unearthing the Dragon: The Great Feathered Dinosaur Discovery |location=New York |publisher=Pi Press |isbn=0-13-186266-9 |url=https://archive.org/details/unearthingdragon00mark }}</ref><ref name="AP-20140731">{{cite news |last=Borenstein |first=Seth |title=Study traces dinosaur evolution into early birds |url=http://apnews.excite.com/article/20140731/us-sci-shrinking-dinosaurs-a5c053f221.html |date=31 July 2014 |agency=Associated Press |access-date=3 August 2014 |archive-url=https://web.archive.org/web/20140808042331/http://apnews.excite.com/article/20140731/us-sci-shrinking-dinosaurs-a5c053f221.html |archive-date=8 August 2014 }}</ref><ref name="SCI-20140731">{{cite journal |title=Sustained miniaturization and anatomical innovation in the dinosaurian ancestors of birds |date=1 August 2014 |journal=[[Science (journal)|Science]] |volume=345 |issue=6196 |pages=562–566 |doi=10.1126/science.1252243 |last1=Lee |first1=Michael S. Y. |first2=Andrea|last2=Cau |first3=Darren|last3=Naish|first4=Gareth J.|last4=Dyke |bibcode=2014Sci...345..562L |pmid=25082702 }}</ref>

[[File:Anchiornis feathers.jpg|thumb|''[[Anchiornis huxleyi]]'' is an important source of information on the early evolution of birds in the [[Late Jurassic]] period.<ref name="lietal2010">{{cite journal |last1=Li |first1=Q. |last2=Gao |first2=K.-Q. |last3=Vinther |first3=J. |last4=Shawkey |first4=M. D. |last5=Clarke |first5=J. A. |last6=d'Alba |first6=L. |last7=Meng |first7=Q. |last8=Briggs |first8=D. E. G. |last9=Prum |first9=R. O. |year=2010 |name-list-style=amp |title=Plumage color patterns of an extinct dinosaur |journal=[[Science (journal)|Science]] |volume=327 |issue=5971 |pages=1369–1372 |bibcode=2010Sci...327.1369L |doi=10.1126/science.1186290 |pmid=20133521 |url=http://doc.rero.ch/record/210394/files/PAL_E4402.pdf }}</ref>]]
The consensus view in contemporary [[paleontology|palaeontology]] is that the flying theropods, or [[Avialae|avialans]], are the closest relatives of the [[deinonychosaur]]s, which include dromaeosaurids and [[troodontid]]s.<ref name=Xiaotingia>{{cite journal |title=An ''Archaeopteryx''-like theropod from China and the origin of Avialae |date=28 July 2011 |journal=Nature |volume=475 |pages=465–470 |doi=10.1038/nature10288 |issue=7357 |author1=Xing Xu |author2=Hailu You |author3=Kai Du |author4=Fenglu Han |pmid=21796204 }}</ref> Together, these form a group called [[Paraves]]. Some [[basal (phylogenetics)|basal]] members of Deinonychosauria, such as ''[[Microraptor]]'', have features which may have enabled them to glide or fly. The most basal deinonychosaurs were very small. This evidence raises the possibility that the ancestor of all paravians may have been [[arboreal]], have been able to glide, or both.<ref name="AHTetal07">{{Cite journal|last1=Turner |first1=Alan H. |last2=Pol |first2=D. |last3=Clarke |first3=J. A. |last4=Erickson |first4=G. M. |last5=Norell |first5=M. A. |date=7 September 2007 |title=A basal dromaeosaurid and size evolution preceding avian flight |journal=[[Science (journal)|Science]] |volume=317 |pages=1378–1381 |doi=10.1126/science.1144066 |pmid=17823350 |issue=5843 |bibcode=2007Sci...317.1378T |doi-access=free }}</ref><ref name="xuetal2003">{{Cite journal|date=23 January 2003|title=Four-winged dinosaurs from China|journal=[[Nature (journal)|Nature]]|volume=421|issue=6921|pages=335–340|doi=10.1038/nature01342|pmid=12540892 |last1=Xu |first1=X. |last2=Zhou |first2=Z. |last3=Wang |first3=X. |last4=Kuang |first4=X. |last5=Zhang |first5=F. |last6=Du |first6=X. |bibcode=2003Natur.421..335X |url=http://doc.rero.ch/record/15275/files/PAL_E2574.pdf }}</ref> Unlike ''Archaeopteryx'' and the non-avialan feathered dinosaurs, who primarily ate meat, studies suggest that the first avialans were [[omnivore]]s.<ref>{{cite web |url=http://the-scientist.com/2011/07/27/on-the-origin-of-birds |title=On the Origin of Birds |access-date=11 June 2012 |author=Luiggi, Christina |date=July 2011 |publisher=The Scientist |archive-url=https://web.archive.org/web/20120616171500/http://the-scientist.com/2011/07/27/on-the-origin-of-birds/ |archive-date=16 June 2012 }}</ref>

The [[Late Jurassic]] ''Archaeopteryx'' is well known as one of the first [[transitional fossil]]s to be found, and it provided support for the [[theory of evolution]] in the late 19th century. ''Archaeopteryx'' was the first fossil to display both clearly traditional reptilian characteristics—teeth, clawed fingers, and a long, lizard-like tail—as well as wings with flight feathers similar to those of modern birds. It is not considered a direct ancestor of birds, though it is possibly closely related to the true ancestor.<ref name="mayretal2007">{{Cite journal |doi=10.1111/j.1096-3642.2006.00245.x |last1=Mayr |first1=G. |last2=Pohl |first2=B. |last3=Hartman |first3=S. |last4=Peters |first4=D. S. |date=January 2007 |title=The tenth skeletal specimen of ''Archaeopteryx''| journal=Zoological Journal of the Linnean Society |volume=149 |issue=1 |pages=97–116 |doi-access=free}}</ref>