Editing Microraptor (section)

==Paleobiology==
===Wings and flight===
''Microraptor'' had four [[wing]]s, one on each of its forelimbs and hindlimbs, somewhat resembling one possible arrangement of the quartet of flight surfaces on a [[tandem wing]] aircraft of today. It had long [[pennaceous feather]]s on arms and hands {{convert|10|–|20|cm|in|adj=mid|long|abbr=on}} with legs and feet {{convert|11|–|15|cm|in|adj=mid|long|abbr=on}}. The long feathers on the legs of ''Microraptor'' were true flight feathers as seen in modern [[bird]]s, with asymmetrical vanes on the arm, leg, and tail feathers. As in modern bird wings, ''Microraptor'' had both primary (anchored to the hand) and secondary (anchored to the arm) flight feathers. This standard wing pattern was mirrored on the hindlegs, with [[flight feather]]s anchored to the upper foot bones as well as the upper and lower leg. Though not apparent in most fossils under natural light, due to obstruction from decayed soft tissue, the feather bases extended close to or in contact with the bones, as in modern birds, providing strong anchor points.<ref name=hone2010>{{cite journal | last1 = Hone | first1 = D.W.E. | last2 = Tischlinger | first2 = H. | last3 = Xu | first3 = X. | last4 = Zhang | first4 = F. | year = 2010 | title = The extent of the preserved feathers on the four-winged dinosaur ''Microraptor gui'' under ultraviolet light | journal = PLOS ONE | volume = 5 | issue = 2| page = e9223 | doi = 10.1371/journal.pone.0009223 | pmid=20169153 | pmc=2821398 | bibcode = 2010PLoSO...5.9223H | doi-access = free }}</ref>

It was originally thought that ''Microraptor'' was a [[Gliding flight|glider]], and probably lived mainly in trees, because the hindwings anchored to the feet of ''Microraptor'' would have hindered their ability to run on the ground.<ref name="Xuetal2003">Xu, X., Zhou, Z., Wang, X., Kuang, X., Zhang, F. and Du, X. (2003). "Four-winged dinosaurs from China." ''Nature'', '''421'''(6921): 335-340, 23 Jan 2003.</ref> Some paleontologists have suggested that feathered dinosaurs used their wings to parachute from trees, possibly to attack or ambush prey on the ground, as a precursor to gliding or true flight.<ref name="benson2012"/> In their 2007 study, Chatterjee and Templin tested this hypothesis as well, and found that the combined wing surface of ''Microraptor'' was too narrow to successfully parachute to the ground without injury from any significant height. However, the authors did leave open the possibility that ''Microraptor'' could have parachuted short distances, as between closely spaced tree branches.<ref name="chatterjee2007"/><ref name="benson2012">{{cite book|author1=Benson, R.B.J. |author2=Brussatte, S. |year=2012|title=Prehistoric Life|location=London|publisher=Dorling Kindersley|page=332|isbn=978-0-7566-9910-9}}</ref> Wind tunnel experiments have demonstrated that sustaining a high-lift coefficient at the expense of high drag was likely the most efficient strategy for ''Microraptor'' when gliding between low elevations. ''Microraptor'' did not require a sophisticated, 'modern' wing morphology to be an effective glider.<ref>{{cite journal | last1 = Dyke | first1 = Gareth | last2 = de Kat | first2 = Roeland | last3 = Palmer | first3 = Colin | last4 = van der Kindere | first4 = Jacques | last5 = Naish | first5 = Darren | last6 = Ganapathisubramani | first6 = Bharathram | year = 2013 | title = Aerodynamic performance of the feathered dinosaur Microraptor and the evolution of feathered flight | journal = Nature Communications | volume = 4 | page = 2489 | doi = 10.1038/ncomms3489 | pmid = 24048346 | bibcode = 2013NatCo...4.2489D | doi-access = free }}</ref> However, the idea that ''Microraptor'' was an arboreal glider relies on it to have regularly climbed or even lived in trees, when study of its anatomy have shown that its limb proportions fall in line with modern ground birds rather than climbers, and its skeleton shows none of the expected adaptations in animals specialized for climbing trees.<ref>{{Cite journal|last1=Dececchi|first1=T. Alexander|last2=Larsson|first2=Hans C. E.|date=2011-08-09|editor-last=Farke|editor-first=Andrew Allen|title=Assessing Arboreal Adaptations of Bird Antecedents: Testing the Ecological Setting of the Origin of the Avian Flight Stroke|journal=PLOS ONE|language=en|volume=6|issue=8|pages=e22292|doi=10.1371/journal.pone.0022292|issn=1932-6203|pmc=3153453|pmid=21857918|bibcode=2011PLoSO...622292D|doi-access=free}}</ref><ref name=Dececchi_etal_2016>{{cite journal | last1 = Dececchi | first1 = T.A. | last2 = Larsson | first2 = H.C.E. | last3 = Habib | first3 = M.B. | year = 2016 | title = The wings before the bird: an evaluation of flapping-based locomotory hypotheses in bird antecedents | journal = PeerJ | volume = 4 | page = e2159 | doi = 10.7717/peerj.2159 | pmid=27441115 | pmc=4941780 | doi-access = free }}</ref>

[[File:Microraptor gui holotype under UV light.png|thumb|''M. gui'' [[holotype]] under two different UV light filters, revealing the extent of preserved feathers and soft tissue]]
Describing specimens originally referenced as a distinctive species (''Cryptovolans pauli''), paleontologist Stephen Czerkas argued ''Microraptor'' may have been a powered flier, and indeed possibly a better flyer than ''[[Archaeopteryx]]''. He noted that the ''Microraptor's'' fused sternum, asymmetrical feathers, and features of the shoulder girdle indicated that it could fly under its own power, rather than merely gliding. Today, most scientists agree that ''Microraptor'' had the anatomical features expected of a flying animal, though it would have been a less advanced form of flight compared to birds. For example, some studies suggest the shoulder joint was too primitive to allow a full flapping flight stroke. In the ancestral anatomy of theropod dinosaurs, the shoulder socket faced downward and slightly backward, making it impossible for the animals to raise their arms vertically, a prerequisite for the flapping flight stroke in birds. Studies of maniraptoran anatomy have suggested that the shoulder socket did not shift into the bird-like position of a high, upward orientation close to the [[vertebra]]l column until relatively advanced avialans like the [[enantiornithes]] appeared.<ref name=senter2006>{{cite journal | last1 = Senter | first1 = P | year = 2006 | title = Scapular orientation in theropods and basal birds, and the origin of flapping flight | journal = Acta Palaeontol. Pol. | volume = 51 | pages = 305–313 }}</ref> However, other scientists have argued that the shoulder girdle in some [[Paraves|paravian]] theropods, including ''Microraptor'', is curved in such a way that the shoulder joint could only have been positioned high on the back, allowing for a nearly vertical upstroke of the wing. This possibly advanced shoulder anatomy, combined with the presence of a [[Patagium|propatagium]] linking the wrist to the shoulder (which fills the space in front of the flexed wing and may support the wing against drag in modern birds) and an [[alula]], much like a "thumb-like" form of [[leading edge slot]], may indicate that ''Microraptor'' was capable of true, powered flight.<ref name=avianancestry>{{Cite journal|author1=Federico L. Agnolín |author2=Fernando E. Novas |name-list-style=amp |year=2013 |title=Avian ancestors. A review of the phylogenetic relationships of the theropods Unenlagiidae, Microraptoria, ''Anchiornis'' and Scansoriopterygidae |journal=SpringerBriefs in Earth System Sciences |pages=1–96 |doi=10.1007/978-94-007-5637-3 |isbn=978-94-007-5636-6 |s2cid=199493087 }}</ref>

Other studies have demonstrated that the wings of ''Microraptor'' were large enough to generate the lift necessary for powered launching into flight even without a fully vertical flight stroke. A 2016 study of incipient flight ability in paravians demonstrated that ''Microraptor'' was capable of [[wing-assisted incline running]], as well as wing-assisted leaping and even ground-based launching.<ref name=Dececchi_etal_2016/>

Stephen Czerkas, Gregory S. Paul, and others have argued that the fact ''Microraptor'' could fly and yet is also very clearly a dromaeosaurid suggests that the [[Dromaeosauridae]], including later and larger species such as ''[[Deinonychus]]'', were secondarily flightless. The work of Xu and colleagues also suggested that the ancestors of dromaeosaurids were probably small, arboreal, and capable of [[Gliding flight|gliding]], although later discoveries of more primitive dromaeosaurids with short forelimbs unsuitable for gliding have cast doubt on this view.<ref name="Xuetal2003"/><ref name=Turneretal07>{{cite journal | last1 = Turner | first1 = Alan H. | last2 = Pol | first2 = Diego | last3 = Clarke | first3 = Julia A. | last4 = Erickson | first4 = Gregory M. | last5 = Norell | first5 = Mark | year = 2007 | title = A basal dromaeosaurid and size evolution preceding avian flight | journal = Science | volume = 317 | issue = 5843| pages = 1378–1381 | doi = 10.1126/science.1144066 | pmid = 17823350 | bibcode = 2007Sci...317.1378T | doi-access = free }}</ref> Work done on the question of flight ability in other paravians, however, showed that most of them probably would not have been able to achieve enough lift for powered flight, given their limited flight strokes and relatively smaller wings. These studies concluded that ''Microraptor'' probably evolved flight and its associated features (fused sternum, alula, etc.) independently of the ancestors of birds.<ref name=Dececchi_etal_2016/><ref>{{Cite journal|last1=Hartman|first1=Scott|last2=Mortimer|first2=Mickey|last3=Wahl|first3=William R.|last4=Lomax|first4=Dean R.|last5=Lippincott|first5=Jessica|last6=Lovelace|first6=David M.|date=2019-07-10|title=A new paravian dinosaur from the Late Jurassic of North America supports a late acquisition of avian flight|journal=PeerJ|language=en|volume=7|pages=e7247|doi=10.7717/peerj.7247|issn=2167-8359|pmc=6626525|pmid=31333906 |doi-access=free }}</ref><ref>{{Cite journal|last1=Pei|first1=Rui|last2=Pittman|first2=Michael|last3=Goloboff|first3=Pablo A.|last4=Dececchi|first4=T. Alexander|last5=Habib|first5=Michael B.|last6=Kaye|first6=Thomas G.|last7=Larsson|first7=Hans C.E.|last8=Norell|first8=Mark A.|last9=Brusatte|first9=Stephen L.|last10=Xu|first10=Xing|date=2020|title=Potential for Powered Flight Neared by Most Close Avialan Relatives, but Few Crossed Its Thresholds|url=|journal=Current Biology|volume=30|issue=20|language=en|pages=4033–4046.e8|doi=10.1016/j.cub.2020.06.105|pmid=32763170|doi-access=free|bibcode=2020CBio...30E4033P |hdl=11336/143103|hdl-access=free}}</ref><ref name=D20>{{cite journal |last1=Dececchi |first1=T. Alexander |last2=Larsson |first2=Hans C. E. |last3=Pittman |first3=Michael |last4=Habib |first4=Michael B. |title=High flyer or high fashion? A comparison of flight potential among small-bodied paravians |journal=Bulletin of the American Museum of Natural History |date=2020 |volume=440 |pages=295–320 |url=http://digitallibrary.amnh.org/bitstream/handle/2246/7237/440-11-dececchi_et_al.pdf}}</ref> In 2024, Kiat and O'Connor analyzed that Mesozoic birds and ''Microraptor'' had remex morphologies that are consistent with modern volant birds, while [[Anchiornithidae|anchiornithid]]s and ''[[Caudipteryx]]'' were secondarily flightless.<ref>{{cite journal |last1=Kiat |first1=Yosef |last2=O’Connor |first2=Jingmai K. |title=Functional constraints on the number and shape of flight feathers |journal=Proceedings of the National Academy of Sciences |date=20 February 2024 |volume=121 |issue=8 |pages=e2306639121 |doi=10.1073/pnas.2306639121 |pmid=38346196 |pmc=10895369 |bibcode=2024PNAS..12106639K |issn=0027-8424}}</ref>

===Hindwing posture===
[[File:Microraptor models.png|thumb|Wind tunnel experiments with different wing configurations]]
[[Sankar Chatterjee]] suggested in 2005 that, in order for ''Microraptor'' to [[Gliding flight|glide]] or fly, the forewings and hindwings must have been on different levels (as on a [[biplane]]) and not overlaid (as on a [[dragonfly]]), and that the latter posture would have been anatomically impossible. Using this biplane model, Chatterjee was able to calculate possible methods of gliding and determined that ''Microraptor'' most likely employed a ''[[phugoid]]'' style of gliding: launching itself from a perch, the animal would have swooped downward in a deep U-shaped curve and then lifted again to land on another tree. The feathers not directly employed in the biplane [[wing]] structure, like those on the [[tibia]] and the [[tail]], could have been used to control drag and alter the [[Airway (aviation)|flight path]], [[trajectory]], etc. The orientation of the hindwings would also have helped the animal control its gliding flight. Chatterjee also used computer [[algorithm]]s that test [[Flying and gliding animals|animal flight]] capacity to test whether or not ''Microraptor'' was capable of true, powered flight, as opposed to or in addition to passive gliding. The resulting data showed that ''Microraptor'' did have the requirements to sustain level powered flight, so it is theoretically possible that the animal flew, as opposed to gliding.<ref name="chatterjee2007">{{cite journal | last1 = Chatterjee | first1 = S. | last2 = Templin | first2 = R.J. | year = 2007 | title = Biplane wing planform and flight performance of the feathered dinosaur ''Microraptor gui'' | url = http://www.pnas.org/cgi/reprint/0609975104v1.pdf | journal = Proceedings of the National Academy of Sciences | volume = 104 | issue = 5| pages = 1576–1580 | doi=10.1073/pnas.0609975104 | pmid=17242354 | pmc=1780066| bibcode = 2007PNAS..104.1576C | doi-access = free }}</ref>

Some paleontologists have doubted the biplane hypothesis, and have proposed other configurations. A 2010 study by Alexander ''et al.'' described the construction of a lightweight three-dimensional physical model used to perform glide tests. Using several hindleg configurations for the model, they found that the biplane model, while not unreasonable, was structurally deficient and needed a heavy-headed weight distribution for stable gliding, which they deemed unlikely. The study indicated that a laterally abducted hindwing structure represented the most biologically and aerodynamically consistent configuration for ''Microraptor''.<ref name=alexanderetal2010>{{cite journal | last1 = Alexander | first1 = D.E. | last2 = Gong | first2 = E. | last3 = Martin | first3 = L.D. | last4 = Burnham | first4 = D.A. | last5 = Falk | first5 = A.R. | year = 2010 | title = Model tests of gliding with different hindwing configurations in the four-winged dromaeosaurid ''Microraptor gui'' | journal = Proceedings of the National Academy of Sciences, USA | volume = 107 | issue = 7| pages = 2972–2976 | doi = 10.1073/pnas.0911852107 | pmid = 20133792 | bibcode = 2010PNAS..107.2972A | pmc = 2840342 | doi-access = free }}</ref> A further analysis by Brougham and Brusatte, however, concluded that Alexander's model reconstruction was not consistent with all of the available data on ''Microraptor'' and argued that the study was insufficient for determining a likely flight pattern for ''Microraptor''. Brougham and Brusatte criticized the anatomy of the model used by Alexander and his team, noting that the hip anatomy was not consistent with other dromaeosaurs. In most dromaeosaurids, features of the hip bone prevent the legs from splaying horizontally; instead, they are locked in a vertical position below the body. Alexander's team used a specimen of ''Microraptor'' which was crushed flat to make their model, which Brougham and Brusatte argued did not reflect its actual anatomy.<ref>{{cite journal | last1 = Brusatte | first1 = Stephen L. | last2 = Brougham | first2 = Jason | year = 2010| title = Distorted ''Microraptor'' specimen is not ideal for understanding the origin of avian flight | journal = Proceedings of the National Academy of Sciences, USA | volume = 107| issue = 40| pages = E155| doi = 10.1073/pnas.1004977107 | pmid = 20864633 | bibcode = 2010PNAS..107E.155B| pmc = 2951411| doi-access = free }}</ref> Later in 2010, Alexander's team responded to these criticisms, noting that the related dromaeosaur ''[[Hesperonychus]]'', which is known from complete hip bones preserved in three dimensions, also shows hip sockets directed partially upward, possibly allowing the legs to splay more than in other dromaeosaurs.<ref>{{cite journal | last1 = Alexander | first1 = D.E. | last2 = Gong | first2 = E. | last3 = Martin | first3 = L.D. | last4 = Burnham | first4 = D.A. | last5 = Falk | first5 = A.R. | year = 2010 | title = Reply to Brougham and Brusatte: Overall anatomy confirms posture and flight model offers insight into the evolution of bird flight | journal = Proceedings of the National Academy of Sciences, USA | volume = 107| issue = 40| pages = E155| doi = 10.1073/pnas.1004977107 | pmid = 20864633 | bibcode = 2010PNAS..107E.155B | pmc = 2951411 | doi-access = free }}</ref> However, Hartman and colleagues suggested that ''Hesperonychus'' is not a dromaeosaur, but actually an [[Avialae|avialan]] close to modern [[bird]]s like ''[[Balaur bondoc]]'' based on phylogenetic analyses in 2019.<ref name=H19>{{Cite journal |last1=Hartman |first1=Scott |last2=Mortimer |first2=Mickey |last3=Wahl |first3=William R. |last4=Lomax |first4=Dean R. |last5=Lippincott |first5=Jessica |last6=Lovelace |first6=David M. |date=2019-07-10 |title=A new paravian dinosaur from the Late Jurassic of North America supports a late acquisition of avian flight |journal=PeerJ |language=en |volume=7 |pages=e7247 |doi=10.7717/peerj.7247 |issn=2167-8359 |pmc=6626525 |pmid=31333906 |doi-access=free }}</ref>

===Ground movement===
[[File:Microraptor by durbed.jpg|thumb|Restoration of two individuals by the ground]]
Due to the extent of the hindwings onto most of the animal's foot, many scientists have suggested that ''Microraptor'' would have been awkward during normal ground movement or running. The front wing feathers would also have hindered ''Microraptor'' when on the ground, due to the limited range of motion in the wrist and the extreme length of the wing feathers. A 2010 study by Corwin Sullivan and colleagues showed that, even with the wing folded as far as possible, the feathers would still have dragged along the ground if the arms were held in a neutral position, or extended forward as in a predatory strike. Only by keeping the wings elevated, or the upper arm extended fully backward, could ''Microraptor'' have avoided damaging the wing feathers. Therefore, it may have been anatomically impossible for ''Microraptor'' to have used its clawed forelimbs in capturing prey or manipulating objects.<ref name=sullivanetal2010>{{cite journal | last1 = Sullivan | first1 = C. | last2 = Hone | first2 = D.W.E. | last3 = Xu | first3 = X. | last4 = Zhang | first4 = F. | year = 2010 | title = The asymmetry of the carpal joint and the evolution of wing folding in maniraptoran theropod dinosaurs | journal = Proceedings of the Royal Society B | volume = 277 | issue = 1690| pages = 2027–2033 | doi = 10.1098/rspb.2009.2281 | pmid = 20200032 | pmc = 2880093 }}</ref>

===Implications===
[[File:Tetrapteryx.jpg|thumb|left|[[William Beebe]]'s hypothetical "''Tetrapteryx''" with four wings, 1915]]
The unique wing arrangement found in ''Microraptor'' raised the question of whether the evolution of flight in modern birds went through a four-winged stage, or whether four-winged gliders like ''Microraptor'' were an evolutionary side-branch that left no descendants. As early as 1915, [[Natural history|naturalist]] [[William Beebe]] had argued that the evolution of bird flight may have gone through a four-winged (or ''tetrapteryx'') stage.<ref name="beebe1915">{{cite journal | last1 = Beebe | first1 = C. W. A. | year = 1915 | title = Tetrapteryx stage in the ancestry of birds | journal = Zoologica | volume = 2 | pages = 38–52 }}</ref> Chatterjee and Templin did not take a strong stance on this possibility, noting that both a conventional interpretation and a tetrapteryx stage are equally possible. However, based on the presence of unusually long leg feathers in various feathered dinosaurs, ''[[Archaeopteryx]]'', and some modern birds such as raptors, as well as the discovery of further dinosaurs with long primary feathers on their feet (such as ''[[Pedopenna]]''), the authors argued that the current body of evidence, both from morphology and phylogeny, suggests that bird flight did shift at some point from shared limb dominance to front-limb dominance and that all modern birds may have evolved from four-winged ancestors, or at least ancestors with unusually long leg feathers relative to the modern configuration.<ref name="chatterjee2007"/>

===Feeding===
[[File:Microraptor cast in Horniman Museum.jpg|thumb|Cast in [[Horniman Museum]]]]
In 2010 researchers announced that further preparation of the type fossil of ''M. zhaoianus'' revealed preserved probable gut contents, and a full study on them was later published in 2022 by David Hone and colleagues. These consisted of the remains of a mammal, primarily a complete and articulated right foot (including all [[Tarsal bone|tarsals]], [[metatarsals]], and most of the [[phalanges]]) as well as the shafts of additional long bones and potentially other fragments. The foot skeleton is similar to those of ''[[Eomaia]]'' and ''[[Sinodelphys]]''. It corresponds to an animal with an estimated snout to vent length of {{cvt|80|mm}} and a mass of {{cvt|13|–|43|g}}. The unguals of the foot are less curved than in ''Eomaia'' or ''Sinodelphys'', indicating that the mammal could climb but less effectively than in the two latter genera and so was likely not arboreal but potentially scansorial.<ref name="Larsson et al. 2010"/><ref name="Hone22"/>

It is ambiguous whether the mammal had been predated upon or scavenged by the ''Microraptor'', although the lack of other definitive body parts consumed may suggest the low-muscle mass foot may have been eaten during a late stage of carcass consumption, possibly through scavenging. The find is a rare example of a theropod definitively consuming a Mesozoic mammal.<ref name="Larsson et al. 2010">Larsson, Hans, Hone, David, Dececchi, T. Alexander, Sullivan, Corwin, Xu, Xing. "THE WINGED NON-AVIAN DINOSAUR MICRORAPTOR FED ON MAMMALS: IMPLICATIONS FOR THE JEHOL BIOTA ECOSYSTEM" "Program and Abstracts. 70th Anniversary Meeting Society of Vertebrate Paleontology October 2010" 114A.</ref><ref name="Hone22">{{Cite journal |last1=Hone |first1=D. W. |last2=Dececchi |first2=T. A. |last3=Sullivan |first3=C. |last4=Xu |first4=X. |last5=Larsson |first5=H. C. |year=2022 |title=Generalist diet of ''Microraptor zhaoianus'' included mammals |journal=Journal of Vertebrate Paleontology |volume=43 |issue=e2144337 |at=e2144337 |doi=10.1080/02724634.2022.2144337|bibcode=2022JVPal..42E4337H |s2cid=255051527 |url=https://zenodo.org/record/7477141 }}</ref> The only other two examples are the indeterminate [[tyrannosauroid]] specimen GMV 2124 (also known as NGMC 2124) and the holotype of ''[[Huadanosaurus]]'', both of which are previously attributed to ''[[Sinosauropteryx]]''.<ref>{{Cite journal |last1=Qiu |first1=Rui |last2=Wang |first2=Xiaolin |last3=Jiang |first3=Shunxing |last4=Meng |first4=Jin |last5=Zhou |first5=Zhonghe |date=2025-02-22 |title=Two new compsognathid-like theropods show diversified predation strategies in theropod dinosaurs |journal=National Science Review |volume=12 |issue=5 |pages=nwaf068 |language=en |doi=10.1093/nsr/nwaf068 |issn=2095-5138|doi-access=free |pmid=40191255 |pmc=11970238 }}</ref>

In the December 6, 2011 issue of ''Proceedings of the National Academy of Sciences'', Jingmai O'Connor and coauthors described a specimen of ''Microraptor gui'' containing bones of an arboreal [[enantiornithean]] bird in its abdomen, specifically a partial wing and feet. Their position implies the bird was swallowed whole and head-first, which the authors interpreted as implying that the ''Microraptor'' had caught and consumed the bird in the trees, rather than scavenging it.<ref>{{cite journal |author1=Jingmai O'Connor |author2=Zhonghe Zhou |author3=Xing Xu |name-list-style=amp |year=2011 |title=Additional specimen of ''Microraptor'' provides unique evidence of dinosaurs preying on birds |journal=Proceedings of the National Academy of Sciences of the United States of America |volume=108 |issue=49 |pages=19662–19665 |doi=10.1073/pnas.1117727108 |pmid=22106278 |pmc=3241752|bibcode=2011PNAS..10819662O |doi-access=free }}</ref>

In 2013 researchers announced that they had found fish scales in the abdominal cavity of another ''M. gui'' specimen.<ref name=Xing13>{{cite journal |author=Lida Xing|year=2013 |title=Piscivory in the feathered dinosaur ''Microraptor'' |journal=Evolution|doi=10.1111/evo.12119|display-authors=etal |volume=67 |issue=8 |pages=2441–2445 |pmid=23888864|s2cid=34471616 |doi-access=free }}</ref> The authors contradicted the prior suggestion that ''M. gui'' hunted only in an arboreal environment, proposing that it was also an adept hunter of fish as well. They further argued that the specimen showed a probable adaptation to a fish-eating diet, pointing to the first three teeth of the mandible being inclined anterodorsally, a characteristic often associated with piscivory.<ref name=Xing13/> They concluded that ''Microraptor'' was an opportunistic feeder, hunting the most common prey in both arboreal and aquatic habitats.<ref name=Xing13/>

Both of these studies regarded each gut contents as instances of predation. However, Hone and colleagues (2022) questioned the reliability of these interpretations and wrote that both could just as equally be attributed to scavenging. Further, they argued against ''Microraptor'' being a specialist in either or both arboreal or aquatic hunting, citing the broad range of vertebrate gut contents (i.e. fish, mammals, lizards, birds) as evidence for a generalist hunting strategy, and that neither required that ''Microraptor'' being a specialist for hunting in either habitats.<ref name="Hone22"/>

In 2019, a new genus of [[scleroglossa]]n [[lizard]] (''[[Indrasaurus]]'') was described from a specimen found in the stomach of a ''Microraptor''. The ''Microraptor'' apparently swallowed its prey head first, a behavior typical of modern [[Carnivore|carnivorous]] [[bird]]s and lizards. The ''Indrasaurus'' bones lacked marked pitting and scarring, indicating that the ''Microraptor'' died shortly after eating the lizard and before significant digestion had occurred.<ref name=":0">{{Cite journal|last1=Zhou|first1=Zhonghe|last2=Zhang|first2=Xiaomei|last3=Wang|first3=Yan|last4=Wang|first4=Xiaoli|last5=Dong|first5=Liping|last6=Zheng|first6=Xiaoting|last7=O’Connor|first7=Jingmai|date=2019-07-11|title=Microraptor with Ingested Lizard Suggests Non-specialized Digestive Function|journal=Current Biology|volume=29|language=en|issue=14|pages=2423–2429.e2|doi=10.1016/j.cub.2019.06.020|issn=0960-9822|pmid=31303494|doi-access=free|bibcode=2019CBio...29E2423O }}</ref>

Unlike its fellow [[Paraves|paravian]] ''[[Anchiornis]]'', ''Microraptor'' has never been found with [[Pellet (ornithology)|gastric pellets]], despite the existence of four ''Microraptor'' specimens that preserve stomach contents. This suggests that ''Microraptor'' passed indigestible fur, feathers, and bits of bone in its droppings instead of producing pellets.<ref name=":0" />

Based on the size of the [[Sclerotic ring|scleral ring]] of the eye, it has been suggested ''Microraptor'' hunted at night.<ref>{{cite journal | title=Nocturnality in dinosaurs inferred from scleral ring and orbit morphology|vauthors=Schmitz L, Motani R | journal=Science| year=2011| doi=10.1126/science.1200043| pmid=21493820| volume=332 | issue=6030 | pages=705–8| bibcode=2011Sci...332..705S|s2cid=33253407 }}</ref> However, the discovery of iridescent plumage in ''Microraptor'' has cast doubt on this conclusion, as no modern birds that have iridescent plumage are known to be nocturnal.<ref name="iridescence"/>