Editing Maniraptora

{{Short description|Clade of dinosaurs}}
{{Automatic taxobox
| name = Maniraptorans
| fossil_range = <br />[[Middle Jurassic]]–[[Holocene|Present]], {{Fossil range|165|earliest=Early Jurassic|0|ref=<ref>{{cite journal | last1 = Zhang | first1 = H. | last2 = Wang | first2 = M. | last3 = Liu | first3 = X. | year = 2008 | title = Constraints on the upper boundary age of the Tiaojishan Formation volcanic rocks in West Liaoning-North Hebei by LA-ICP-MS dating | journal = Chinese Science Bulletin | volume = 53 | issue = 22| pages = 3574–3584 | doi = 10.1007/s11434-008-0287-4| bibcode = 2008SciBu..53.3574Z }}</ref>}}<small>Possible [[Early Jurassic]] record<ref>{{cite journal|last1=Barrett|first1=P. M.|date=2009|title=The affinities of the enigmatic dinosaur ''Eshanosaurus deguchiianus'' from the Early Jurassic of Yunnan Province, People's Republic of China|journal=Palaeontology|volume=52|issue=4|pages=681−688|doi=10.1111/j.1475-4983.2009.00887.x|doi-access=|bibcode=2009Palgy..52..681B }}</ref></small>
| image = Maniraptora Infobox Panoply.png
| image_upright = 1.3
| image_caption = Collage of six maniraptorans. From top left to right: the Zamyn Khondt [[oviraptorid]], ''[[Sinornithosaurus]]'', the [[Prince Creek Formation|Prince Creek]] [[troodontid]], ''[[Patagonykus]]'', a [[short-tailed albatross]], and ''[[Nothronychus]]''
| taxon = Maniraptora
| authority = [[Jacques Gauthier|Gauthier]], 1986
| subdivision_ranks = Subgroups
| subdivision = * {{extinct}}''[[Fukuivenator]]''
* {{extinct}}''[[Juravenator]]''?
* {{extinct}}''[[Migmanychion]]''
* {{extinct}}''[[Ornitholestes]]''?
* {{extinct}}''[[Unquillosaurus]]''
* {{extinct}}''[[Yaverlandia]]''
* {{extinct}}'''[[Alvarezsauroidea]]'''
* {{extinct}}'''[[Therizinosauria]]'''
* '''Pennaraptora'''<br><small>Foth, Tischlinger & Rauhut, 2014</small>
** {{extinct}}'''[[Oviraptorosauria]]'''
** {{extinct}}'''[[Scansoriopterygidae]]'''
** '''[[Paraves]]'''
| synonyms = *'''Metornithes''' <small>Perle et al., 1993</small>
}}

'''Maniraptora''' is a [[clade]] of [[coelurosauria]]n [[dinosaur]]s which includes the [[bird]]s and the non-avian dinosaurs that were more closely related to them than to ''[[Ornithomimus velox]]''. It contains the major subgroups [[Avialae]], [[Dromaeosauridae]], [[Troodontidae]], [[Oviraptorosauria]], and [[Therizinosauria]]. ''[[Ornitholestes]]'' and the [[Alvarezsauroidea]] are also often included. Together with the next closest sister group, the [[Ornithomimosauria]], Maniraptora comprises the more inclusive clade [[Maniraptoriformes]]. Maniraptorans first appear in the fossil record during the [[Jurassic Period]] (see ''[[Eshanosaurus]]''), and [[origin of birds#Phylogeny|survive today]] as living birds.

==Description==
[[File:MicroraptorGui-PaleozoologicalMuseumOfChina-May23-08.jpg|thumb|left|''[[Microraptor]]'' specimen with feather impressions]]
Maniraptorans are characterized by long arms and three-fingered hands (though reduced or fused in some lineages), as well as a "half-moon shaped" ([[semilunar bone|semi-lunate]]) bone in the wrist ([[Carpal bones|carpus]]). In 2004, Tom Holtz and Halszka Osmólska pointed out six other maniraptoran characteristics relating to specific details of the skeleton. Unlike most other [[saurischia]]n dinosaurs, which have pubic bones that point forward, several groups of maniraptorans have an [[ornithischia]]n-like backwards-pointing hip bone. A backward-pointing hip characterizes the [[therizinosaur]]s, [[Dromaeosauridae|dromaeosaurids]], [[Avialae|avialans]], and some primitive [[Troodontidae|troodontids]]. The fact that the backward-pointing hip is present in so many diverse maniraptoran groups has led most scientists to conclude that the "primitive" forward-pointing hip seen in advanced troodontids and [[Oviraptorosauria|oviraptorosaurs]] is an evolutionary reversal, and that these groups evolved from ancestors with backward-pointing hips.<ref name="HoltzOsmolska.04">Holtz, T.R. and Osmólska, H. (2004). "Saurischia." In Weishampel, Dodson and Osmólska (eds.), ''The Dinosauria'', second edition. Berkeley: University of California Press.</ref>

===Technical diagnosis===
Holtz and Osmólska (2004) diagnosed the clade Maniraptora based on the following characters: reduced or absent [[olecranon process]] of the [[ulna]], [[greater trochanter]] and [[cranial trochanter]] of the [[femur]] fused into a [[trochanteric crest]]. An elongated, backwards-pointing pubic bone is present in therizinosauroids, dromaeosaurids, avialans, and the basal troodontid ''[[Sinovenator]]'', which suggests that the propubic condition in advanced troodontids and oviraptorosaurs is a reversal.<ref name="HoltzOsmolska.04"/> Turner ''et al.'' (2007) named seven synapomorphies that diagnose Maniraptora.<ref name="turneretal2007a"/>

===Feathers and flight===
[[File:Branta canadensis -near Oceanville, New Jersey, USA -flying-8.jpg|thumb|left|[[Canada goose]] flying]]
Modern [[pennaceous feather]]s and [[remiges]] are known in the advanced maniraptoran group [[Aviremigia]]. More primitive maniraptorans, such as therizinosaurs (specifically ''[[Beipiaosaurus]]''), preserve a combination of simple downy filaments and unique elongated quills.<ref name="xu99">{{Cite journal | doi = 10.1038/20670 | last1 = Xu | first1 = X. | last2 = Tang | first2 = Z-L. | last3 = Wang | first3 = X-L. | year = 1999 | title = A therizinosauroid dinosaur with integumentary structures from China | journal = Nature | volume = 399 | issue = 6734| pages = 350–354| bibcode = 1999Natur.399..350X | s2cid = 204993327 }}</ref><ref name="xu2009">Xu X., Zheng X.-t. and You, H.-l. (2009). "A new feather type in a nonavian theropod and the early evolution of feathers." ''Proceedings of the National Academy of Sciences (Philadelphia)'', {{doi|10.1073/pnas.0810055106}}</ref> Simple feathers are known from more primitive coelurosaurs such as ''[[Sinosauropteryx prima]]'', and possibly from even more distantly related species such as the [[ornithischia]]n ''[[Tianyulong confuciusi]]'' and the flying [[pterosaur]]s. Thus it appears as if some form of feathers or down-like [[integument]] would have been present in all maniraptorans, at least when they were young.<ref name=turneretal2007a>{{cite journal |last=Turner |first=A.H. |author2=Pol, D. |author3=Clarke, J.A. |author4=Erickson, G.M. |author5=Norell, M. |year=2007 |title=A basal dromaeosaurid and size evolution preceding avian flight |url=http://www.sciencemag.org/cgi/reprint/317/5843/1378.pdf |journal=Science |volume=317 |pages=1378–1381 |doi=10.1126/science.1144066 |pmid=17823350 |issue=5843|bibcode=2007Sci...317.1378T |s2cid=2519726 |doi-access=free }}</ref>

Maniraptora is the only dinosaur group known to include flying members, though how far back in this lineage flight extends is controversial. Powered and/or gliding [[flight]] is believed to have been present in some types of non-avialan paravians, including dromaeosaurids, such as ''[[Rahonavis]]'' and ''[[Microraptor]]''.<ref name="chiappe2007">Chiappe, L.M. (2007). ''Glorified Dinosaurs: The Origin and Early Evolution of Birds.'' Sydney: UNSW Press.</ref> ''[[Zhenyuanlong suni]]'', a [[dromaeosaurid]], was too heavy to fly but still had wings with feathers required for flying, which suggests its ancestors had the ability for aerial locomotion.<ref>[https://www.washingtonpost.com/news/speaking-of-science/wp/2015/07/16/scientists-find-a-new-dinosaur-with-well-preserved-bird-like-wings-but-not-for-flight/ Scientists find a new dinosaur with well preserved, bird-like wings — but not for flight]</ref> Other groups, like the [[Oviraptorosauria]] who had a tail with a tail fan of feathers with caudal anatomy resembling a [[pygostyle]], are not known to have been capable of flight, but some scientists, such as [[Gregory S. Paul]], have suggested that they could be descended from ancestors which flew. Paul has gone as far as to propose that [[Therizinosauria]], [[Alvarezsauroidea]], and the non-maniraptoran group [[Ornithomimosauria]] also descended from flying ancestors.<ref name=paul2002>{{cite book| author = Paul, G.S.| year = 2002| title = Dinosaurs of the Air: The Evolution and Loss of Flight in Dinosaurs and Birds| location = Baltimore| publisher = Johns Hopkins University Press}}</ref>

==Classification==
The Maniraptora was originally named by [[Jacques Gauthier]] in 1986, for a [[Phylogenetic nomenclature|branch-based]] [[clade]] defined as all dinosaurs closer to modern birds than to the [[Ornithomimidae|ornithomimids]]. Gauthier noted that this group could be easily characterized by their long forelimbs and hands, which he interpreted as adaptations for grasping (hence the name Maniraptora, which means "hand snatchers" in relation to their 'seizing hands'). In 1994, [[Thomas R. Holtz]] attempted to define the group based on the characteristics of the hand and wrist alone (an ''[[Phylogenetic nomenclature|apomorphy-based]]'' definition), and included the long, thin fingers, bowed, wing-like forearm bones, and half-moon shaped wrist bone as key characters. Most subsequent studies have not followed this definition, however, preferring the earlier branch-based definition.

The branch-based definition usually includes the major groups [[Dromaeosauridae]], [[Troodontidae]], [[Oviraptorosauria]], [[Therizinosauria]], and [[Avialae]].<ref name="zannoetal2009">Zanno, L.E., Gillette, D.D., Albright, L.B., and Titus, A.L. (2009). "A new North American therizinosaurid and the role of herbivory in 'predatory' dinosaur evolution." ''Proceedings of the Royal Society B'', Published online before print July 15, 2009, {{doi|10.1098/rspb.2009.1029}}.</ref> Other taxa often found to be maniraptorans include the [[Alvarezsauroidea|alvarezsaurs]] and ''[[Ornitholestes]]''.<ref name=turneretal2007a/><ref>{{Cite journal |last1=Meso |first1=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 |date=2024 |language=en |volume=n/a |issue=n/a |doi=10.1111/cla.12600 |issn=1096-0031|pmc=11811816 }}</ref>  Several taxa have been assigned to the Maniraptora more definitively, though their exact placement within the group remains uncertain. These forms include the [[Scansoriopterygidae|scansoriopterygids]], ''[[Pedopenna]]'', and ''[[Yixianosaurus]]''.

In 1993, Perle and colleagues coined the name '''Metornithes''' to include alvarezsaurids and modern birds, which the researchers believed were members of the Avialae. This group was defined as a clade by Luis Chiappe in 1995 as the last common ancestor of ''[[Mononykus]]'' and modern birds, and all its descendants.<ref name=chiappe1995>{{cite journal | last1 = Chiappe | first1 = L.M. | year = 1995 | title = The first 85 million years of avian evolution | journal = Nature | volume = 378 | issue = 6555| pages = 349–355 | doi=10.1038/378349a0| bibcode = 1995Natur.378..349C | s2cid = 4245171 }}</ref>

Pennaraptora (Latin ''penna'' "bird feather" + ''raptor'' "thief", from ''rapere'' "snatch"; a feathered bird-like predator) is a [[clade]] within Maniraptora, defined as the most recent common ancestor of ''[[Oviraptor philoceratops]]'', ''[[Deinonychus antirrhopus]]'', and ''[[Passer domesticus]]'' (the house sparrow), and all descendants thereof, by Foth ''et al.'', 2014.<ref name=foth_archaeopteryx>{{cite journal | doi = 10.1038/nature13467 | title=New specimen of Archaeopteryx provides insights into the evolution of pennaceous feathers | journal=Nature | date=2014 | volume=511 | issue=7507 | pages=79–82 | first1=Christian | last1=Foth | first2=Helmut | last2=Tischlinger | first3=Oliver | last3=Rauhut | pmid=24990749| bibcode=2014Natur.511...79F }}</ref> 

The clade "Aviremigia" was conditionally proposed along with several other [[Synapomorphy and apomorphy|apomorphy]]-based clades relating to [[bird]]s by [[Jacques Gauthier]] and [[Kevin de Queiroz]] in a 2001 paper. Their proposed definition for the group was "the clade stemming from the first [[Panaves|panavian]] with ... [[remiges]] and [[rectrices]], that is, enlarged, stiff-shafted, closed-vaned (= barbules bearing hooked distal pennulae), pennaceous feathers arising from the distal forelimbs and tail".<ref name="gauthier&dequeiroz2001">Gauthier, J. and de Queiroz, K. (2001). "Feathered dinosaurs, flying dinosaurs, crown dinosaurs, and the name 'Aves'". Pp. 7-41 in Gauthier, J. and L.F. Gall (eds.), ''New Perspectives on the Origin and Early Evolution of Birds: Proceedings of the International Symposium in Honor of John H. Ostrom''. New Haven: Peabody Museum of Natural History, Yale University. {{ISBN|0-912532-57-2}}.</ref> Ancestral morphology relating to pennaceous feathers suggests that basal species of Pennaraptora were capable of scansorial locomotion and gliding, and further evolution of said adaptation within the clade would eventually give rise to the origin of flight in avian species.<ref>{{Cite journal |last=Sorkin |first=Boris |date=2021-12-02 |title=Scansorial and aerial ability in Scansoriopterygidae and basal Oviraptorosauria |url=https://doi.org/10.1080/08912963.2020.1855158 |journal=Historical Biology |volume=33 |issue=12 |pages=3202–3214 |doi=10.1080/08912963.2020.1855158 |bibcode=2021HBio...33.3202S |issn=0891-2963|url-access=subscription }}</ref>

The following [[cladogram]] follows the results of a phylogenetic study by Cau (2020).<ref>Cau, Andrea. “The body plan of ''Halszkaraptor escuilliei'' (Dinosauria, Theropoda) is not a transitional form along the evolution of dromaeosaurid hypercarnivory.” ''PeerJ'' vol. 8 e8672. 25 Feb. 2020, doi:10.7717/peerj.8672</ref>
{{clade| style=font-size:100%;line-height:80%
|label1='''Maniraptora'''
|1=
{{clade
    |1={{extinct}}[[Alvarezsauroidea]][[File:Patagonykuspuertai.jpg|75px]]
    |2=
  {{clade
      |1={{extinct}}[[Therizinosauridae]][[File:Therizinosaurus Restoration.png|75px]]
      |label2=[[Pennaraptora]]
      |2=
        {{clade
        |1={{extinct}}[[Oviraptorosauria]][[File:Citipati osmolskae Restoration.png|75px]]
        |label2=[[Paraves]]
        |2= 
          {{clade
          |1={{extinct}}[[Dromaeosauridae]] [[File:Dromaeosaurus Restoration.png|75px]]
          |label2=[[Paraves#Averaptora|Averaptora]]
          |2= 
            {{clade
            |1={{extinct}}[[Troodontidae]][[File:Saurornithoides restoration.png|75px]]
            |2=[[Avialae]] [[File:Confuciusornis plumage pattern.jpg|75px]]
            }}
          }}
        }}
      }}
    }}
}}

===Alternative interpretations===
In 2002, Czerkas and Yuan reported that some maniraptoran traits, such as a long, backwards-pointed [[pubis (bone)|pubis]] and short [[Ischium|ischia]] were present in ''Scansoriopteryx'', a scansoriopterygid. The authors considered it to be more primitive than true theropods, and hypothesized that maniraptorans may have branched off from theropods at a very early point, or may even have descended from pre-theropod dinosaurs.<ref name="czerkas2002">Czerkas, S.A., and Yuan, C. (2002). "An arboreal maniraptoran from northeast China." Pp. 63-95 in Czerkas, S.J. (Ed.), ''Feathered Dinosaurs and the Origin of Flight.'' The Dinosaur Museum Journal '''1'''. The Dinosaur Museum, Blanding, U.S.A. [http://www.dinosaur-museum.org/featheredinosaurs/arboreal_maniraptoran.pdf PDF abridged version]</ref> Zhang ''et al.'', in describing the closely related or conspecific specimen ''[[Epidendrosaurus]]'' (now considered a synonym of ''[[Scansoriopteryx]]''), did not report any of the primitive traits mentioned by Czerkas and Yuan, but did find that the shoulder blade of ''Epidendrosaurus'' appeared primitive. Despite this, they placed ''Epidendrosaurus'' firmly within Maniraptora due to a number of synapomorphies.<ref name="zhang2002">Zhang, F., Zhou, Z., Xu, X. & Wang, X. (2002). "A juvenile coelurosaurian theropod from China indicates arboreal habits." ''Naturwissenschaften'', '''89'''(9): 394-398. doi:10.1007 /s00114-002-0353-8.</ref>

==Paleobiology==
===Diet===
[[File:Jinfengopteryx elegans 2.JPG|thumb|''[[Jinfengopteryx elegans]]'' specimen with seeds preserved in the stomach region]]
Scientists traditionally assumed that maniraptorans were ancestrally [[Hypercarnivore|hypercarnivorous]], that is, that most non-avialan species primarily ate and hunted only other [[vertebrate]]s. However, a number of discoveries made during the first decade of the 21st century, as well as re-evaluation of older evidence, began to suggest that maniraptorans were a primarily [[Omnivore|omnivorous]] group, including a number of sub-groups that ate mainly plants, insects, or other food sources besides meat. Additionally, phylogenetic studies of maniraptoran relationships began to more consistently show that herbivorous or omnivorous groups were spread throughout the Maniraptora, rather than representing a single side-branch as previously thought. This led scientists such as [[Lindsay Zanno]] to conclude that the ancestral maniraptoran must have been omnivorous, giving rise to several purely herbivorous groups (such as the therizinosaurs, primitive oviraptorosaurs, and some avialans) and that, among non-avians, only one group reverted to pure carnivores (the dromaeosaurids). Most other groups fell somewhere in between the two extremes, with alvarezsaurids and some avialans being insectivorous, and with advanced oviraptorosaurs and troodontids being omnivorous.<ref name="zannoetal2009"/><ref name=LC08>{{cite journal |last=Longrich |first=Nicholas R. |author2=Currie, Philip J. |year=2009 |title=''Albertonykus borealis'', a new alvarezsaur (Dinosauria: Theropoda) from the Early Maastrichtian of Alberta, Canada: Implications for the systematics and ecology of the Alvarezsauridae |journal=Cretaceous Research |volume=30 |issue=1 |pages= 239–252 |doi=10.1016/j.cretres.2008.07.005|bibcode=2009CrRes..30..239L }}</ref><ref name="holtzetal1998">{{Cite journal | last1 = Holtz | first1 = T.R. Jr. | last2 = Brinkman | first2 = D.L. | last3 = Chandler | first3 = C.L. | year = 1998 | title = Dental morphometrics and a possibly omnivorous feeding habit for the theropod dinosaur ''Troodon'' | journal = GAIA | volume = 15 | pages = 159–166}}</ref>

=== Reproduction ===
A 2023 study analyzing fossil eggshells assigned to ''[[Troodon]]'' with [[Clumped isotopes|clumped isotope]] thermometry found that ''Troodon'', and likely other non-avian maniraptorans, had a slowed calcification of eggs akin to that of most reptiles. This contrasts with the rapid calcification of eggs found in modern birds, indicating that most maniraptorans aside from birds retained this basal trait. This would also indicate that most non-avian maniraptorans possessed two functional [[Ovary|ovaries]], contrasting with the one functional ovary in birds, and were thus limited in the numbers of eggs each individual could produce.<ref>{{Cite journal |last1=Tagliavento |first1=Mattia |last2=Davies |first2=Amelia J. |last3=Bernecker |first3=Miguel |last4=Fiebig |first4=Jens |date=April 3, 2023 |title=Evidence for heterothermic endothermy and reptile-like eggshell mineralization in Troodon, a non-avian maniraptoran theropod |journal=[[PNAS]] |volume=120 |issue=15 |pages=e2213987120|doi=10.1073/pnas.2213987120 |pmid=37011196 |pmc=10104568 |bibcode=2023PNAS..12013987T }}</ref>

==References==
{{Reflist|25em}}

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{{Portal bar|Birds|Dinosaurs|Evolutionary biology|Paleontology}}

[[Category:Maniraptora| ]]
[[Category:Dinosaur clades]]