Editing Alvarezsauridae (section)

==Classification== 
[[Image:Shuvuuia.jpg|thumb|right|Life restoration of ''Shuvuuia deserti'']]
Turner ''et al.'' (2007) place the alvarezsaurs as the most basal group in the [[Maniraptora]], one step more derived than ''[[Ornitholestes]]'' and two more derived than the [[Ornithomimosauria]]. The alvarezsaurs are more primitive than the [[Oviraptorosauria]].<ref name="Turneretal07">{{cite journal |last1=Turner |first1=A. H. |last2=Pol |first2=D. |last3=Clarke |first3=J. A. |last4=Erickson |first4=G. M. |last5=Norell |first5=M. A. |title=A Basal Dromaeosaurid and Size Evolution Preceding Avian Flight |journal=Science |date=7 September 2007 |volume=317 |issue=5843 |pages=1378–1381 |doi=10.1126/science.1144066 |pmid=17823350 |bibcode=2007Sci...317.1378T |doi-access=free }}</ref>

Novas' 1996 description of ''[[Patagonykus]]'', demonstrated that it was a link between the more primitive (basal) ''Alvarezsaurus'' and the more advanced (derived) ''Mononykus'', and reinforced their monophyly. ''[[Parvicursor]]'' was discovered shortly after, and placed in its own family Parvicursoridae, and then ''Shuvuuia'' in 1998. Everything has since been lumped into Alvarezsauridae, with Mononykinae surviving as a [[subfamily]].

There may be a relationship between the alvarezsaurids and the [[Ornithomimosauria]] as sister clades within either [[Thomas Holtz]]'s [[Arctometatarsalia]] or [[Paul Sereno]]'s [[Ornithomimiformes]]. The discovery of ''[[Haplocheirus]]'', which exhibits transitional features between the more derived alvarezsaurs and other [[maniraptora]]ns, particularly in relation to the skull structure and development of the hand, has provided further support for that relationship.<ref>Choiniere, J. (2010). [http://archosaurmusings.wordpress.com/2010/01/29/guest-post-haplocheirus-%E2%80%93-the-skilful-one/ Guest Post: ''Haplocheirus'', the Skillful One] Dave Hone's Archosaur Musings, April 23, 2011.</ref>

The taxonomy of the alvarezsaurs has been somewhat confused, due to different authors using different names for groups with the same definition. The [[Family (biology)|family]] Alvarezsauridae was first coined by Jose Bonaparte in 1991, but given no specific phylogenetic definition. Novas later defined the group as the most recent common ancestor of ''[[Alvarezsaurus]]'' and ''[[Mononykus]]'' plus all its descendants, though others, such as [[Paul Sereno]], used a more inclusive definition, such as all dinosaurs closer to ''[[Shuvuuia]]'' than to modern birds. In 2009, Livezey and Zusi used the name Alvarezsauroidea for the total group of all alvarezsaurs, restricting the name Alvarezsauridae to the clade defined by ''Alvarezsaurus'' + ''Mononykus''. This was followed by Choiniere and colleagues in 2010, who described the first non-alvarezsaurid alvarezsauroid, ''[[Haplocheirus]]''.<ref name=haplocheirus>{{cite journal |last1=Choiniere |first1=J. N. |last2=Xu |first2=X. |last3=Clark |first3=J. M. |last4=Forster |first4=C. A. |last5=Guo |first5=Y. |last6=Han |first6=F. |title=A Basal Alvarezsauroid Theropod from the Early Late Jurassic of Xinjiang, China |journal=Science |date=29 January 2010 |volume=327 |issue=5965 |pages=571–574 |doi=10.1126/science.1182143 |pmid=20110503 |bibcode=2010Sci...327..571C |s2cid=36904501 }}</ref> Some authors have used the name Mononykinae for the sub-group of alvarezsaurs including the advanced Mongolian species. However, Choiniere and colleagues argued that Parvicursorinae has priority, since its coordinate name under the [[International Code of Zoological Nomenclature|ICZN Code]], Parvicursoridae, was named earlier.<ref name=haplocheirus/> Another subfamily, Patagonykinae, has been named to include the South American ''Patagonykus'' and ''Bonapartenykus'', but a few recent studies have placed them just outside Alvarezsauridae, some of which do not even recover them in a single clade, making Patagonykinae turn out to be paraphyletic.<ref name="agnolinetal2012">{{cite journal |last1=Agnolin |first1=Federico L. |last2=Powell |first2=Jaime E. |last3=Novas |first3=Fernando E. |last4=Kundrát |first4=Martin |date=June 2012 |title=New alvarezsaurid (Dinosauria, Theropoda) from uppermost Cretaceous of north-western Patagonia with associated eggs |journal=Cretaceous Research |volume=35 |pages=33–56 |doi=10.1016/j.cretres.2011.11.014}}</ref><ref name="Xu2018">{{cite journal|doi=10.1016/j.cub.2018.07.057|title=Two Early Cretaceous Fossils Document Transitional Stages in Alvarezsaurian Dinosaur Evolution|journal=Current Biology|year=2018|last1=Xu|first1=Xing|last2=Choiniere|first2=Jonah|last3=Tan|first3=Qingwei|last4=Benson|first4=Roger B.J|last5=Clark|first5=James|last6=Sullivan|first6=Corwin|last7=Zhao|first7=Qi|last8=Han|first8=Fenglu|last9=Ma|first9=Qingyu|last10=He|first10=Yiming|last11=Wang|first11=Shuo|last12=Xing|first12=Hai|last13=Tan|first13=Lin|pmid=30146153|volume=28|issue=17 |pages=2853–2860.e3|doi-access=free}}</ref><ref>{{cite journal|first1=Zichuan |last1=Qin |first2=James |last2=Clark |first3=Jonah |last3=Choiniere |first4=Xing |last4=Xu |year=2019 |title= A new alvarezsaurian theropod from the Upper Jurassic Shishugou Formation of western China|journal=Scientific Reports |volume=9 |issue=1 |page=11727 |doi=10.1038/s41598-019-48148-7 |pmid=31409823 |pmc=6692367 |bibcode=2019NatSR...911727Q }}</ref><ref name=Fowler2020>{{cite journal |author1=Denver W. Fowler |author2=John P. Wilson |author3=Elizabeth A. Freedman Fowler |author4=Christopher R. Noto |author5=Daniel Anduza |author6=John R. Horner |year=2020 |title=''Trierarchuncus prairiensis'' gen. et sp. nov., the last alvarezsaurid: Hell Creek Formation (uppermost Maastrichtian), Montana |journal=Cretaceous Research |volume=116 |pages=Article 104560 |doi=10.1016/j.cretres.2020.104560 |s2cid=225630913 |doi-access=free }}</ref><ref name="Averianov">{{cite journal| vauthors = Averianov AO, Lopatin AV |title=A re-appraisal of ''Parvicursor remotus'' from the Late Cretaceous of Mongolia: implications for the phylogeny and taxonomy of alvarezsaurid theropod dinosaurs |journal=Journal of Systematic Palaeontology |year=2022 |volume=19 |issue=16 |pages=1097–1128 |doi=10.1080/14772019.2021.2013965 |s2cid=247222017 }}</ref><ref name=Dzharaonyx>{{Cite journal |vauthors=Averianov AO, Sues HD |year=2022 |title=New material and diagnosis of a new taxon of alvarezsaurid (Dinosauria, Theropoda) from the Upper Cretaceous Bissekty Formation of Uzbekistan |journal=Journal of Vertebrate Paleontology |volume=41 |issue=5 |pages=e2036174  |doi=10.1080/02724634.2021.2036174 |s2cid=247391327 }}</ref>

The cladogram below is the latest and most comprehensive analysis of alvarezsaurid evolution, following Meso et al. (2024).<ref>{{Cite journal |last=Meso |first=Jorge Gustavo |last2=Pol |first2=Diego |last3=Chiappe |first3=Luis |last4=Qin |first4=Zichuan |last5=Díaz-Martínez |first5=Ignacio |last6=Gianechini |first6=Federico |last7=Apesteguía |first7=Sebastián |last8=Makovicky |first8=Peter J. |last9=Pittman |first9=Michael |title=Body size and evolutionary rate analyses reveal complex evolutionary history of Alvarezsauria |url=https://onlinelibrary.wiley.com/doi/10.1111/cla.12600 |journal=Cladistics |language=en |volume=n/a |issue=n/a |doi=10.1111/cla.12600 |issn=1096-0031|pmc=11811816 }}</ref>{{clade|{{clade
|1={{clade
|label1='''Patagonykinae'''
|1={{clade
|1=''[[Bonapartenykus ultimus]]''
|2=''[[Patagonykus puertai]]'' }}
|2={{clade
|1=''[[Achillesaurus manazzonei]]''
|2=''[[Alvarezsaurus calvoi]]'' }} }}
|label2='''Parvicursorinae'''
|2={{clade
|1=''[[Ceratonykus oculatus]]''
|2={{clade
|1=''[[Khulsanurus magnificus]]''
|2={{clade
|1=''[[Qiupanykus zhangi]]''
|2={{clade
|1=''[[Dzharaonyx eski]]''
|2={{clade
|1={{clade
|1=''[[Linhenykus monodactylus]]''
|2=''[[Parvicursor remotus]]'' }}
|label2='''Mononykini'''
|2={{clade
|1=''[[Shuvuuia deserti]]''
|2={{clade
|1=''[[Mononykus olecranus]]''
|2={{clade
|1=''[[Ondogurvel alifanovi]]''
|2=''[[Albinykus baatar]]'' }} }} }} }} }} }} }} }} }}|style=font-size:85%; line-height:75%;|label1='''Alvarezsauridae'''}}