 tail feathers are unrelated to body size, their presence corresponds to different proportions of the forelimb compared to the hind limb. The authors concluded that the meaning of the observed distributions of both the tail feathers and the body size remains contentious.

Chiappe and colleagues, in their 2008 study, concluded that limb bones growth was almost isometric, meaning that skeletal proportions did not change during growth. This was contested by Peters and Peters in 2009, who observed that wing bones tended to be proportionally longer in very small individuals, as seen in modern chicken, and thus grew allometrically. Chiappe and colleagues, in their 2010 comment, responded that proportional variation is present across the whole size range, and that the presence of allometry was not conclusively demonstrated by the analyses presented by Peters and Peters.

Possible medullary bone
A 2013 histological study by Anusuya Chinsamy and colleagues found medullary bone within the long bones of a short tailed specimen (DNHM-D1874), while three long-tailed specimens lacked medullary bone. In modern birds, medullary bone only forms temporarily in females, where it functions as a calcium reservoir for eggshell production. Therefore, these authors suggested short-tailed specimens to be females, and long-tailed specimens to be males. The female specimen had already passed its rapid growth phase, although it was still significantly smaller than the maximum size reached by Confuciusornis exemplars. At least two lines of arrested growth (growth lines that form annually) could be identified, demonstrating an extended growth over several years; the studied female would have been in its third year. Long tail feathers were confirmed to occur in small individuals, the smallest of which was only around 23% the mass of the largest specimens. Assuming that the occurrence of tail feathers indicates sexual maturity, the authors concluded that the latter must have occurred well before the animals reached their final size, unlike in birds but similar to non-avian dinosaurs. In a 2018 study, Jingmai O'Connor and colleagues questioned the identification of medullary bone, arguing that the purported medullary bone was only found in the forelimb, while in modern birds it is mostly present in the hind limb. Furthermore, the tissue in question is merely preserved as small fragments, rendering its interpretation difficult. However, the authors were able to identify medullary bone in the hind limb of an enantiornithine, a more derived group of Mesozoic birds. As is the case with the Confuc
tail feathers are unrelated to body size, their presence correspond to unlike proportions of the forelimb compared to the hind arm. The authors conclude that the meaning of the observed distribution of both the buttocks feathers and the body size remains contentious. 

 Chiappe and colleagues, in their 2008 sketch, concluded that limb bone increase was almost isometric, meaning that skeletal proportions did not change during increase. This was contested by Peters and Peters in 2009, who observed that wing bone tended to be proportionally longer in very small person, as seen in modern chicken, and thus grew allometrically. Chiappe and colleague, in their 2010 comment, responded that proportional variation is present across the whole size range, and that the presence of allometry was not conclusively demonstrated by the analyses presented by Peters and Peters. 

 Possible medullary bone 
 A 2013 histological study by Anusuya Chinsamy and colleagues found medullary bone within the long bones of a short tailed specimen (DNHM - D1874), while three long - chase specimens lacked medullary bone. In advanced dame, medullary bone only forms temporarily in females, where it officiate as a calcium reservoir for eggshell production. Therefore, these authors suggested abruptly - tailed specimens to be females, and long - tailed specimens to be males. The female specimen had already pass its rapid growth phase, although it was still significantly smaller than the maximal size reached by Confuciusornis exemplar. At least two lines of arrested growth (growth lines that form per annum) could be identified, demonstrating an extended growth over several years; the studied female would have been in its third year. Long buttocks feathers were confirmed to happen in small individuals, the smallest of which was only around 23% the batch of the largest specimen. Assuming that the occurrence of tail feathers indicates intimate maturity, the authors concluded that the latter must have occur well before the animals reached their final size, unlike in birds but similar to non - avian dinosaur. In a 2018 study, Jingmai O'Connor and colleagues wonder the identification of medullary bone, arguing that the purported medullary bone was only found in the forelimb, while in modern birds it is by and large present in the hind limb. Furthermore, the tissue in question is merely preserved as small fragments, rendering its rendition difficult. However, the authors were able to name medullary bone in the hind arm of an enantiornithine, a more derived group of Mesozoic birds. As is the subject with the Confuc
 tall feathers are unrelatea to body size, jhwir prxsence dorrespovds to different proportions od the forelimb compared to ghe hind pimb. The autiors concluded tizt the meaninf of chx observed disttibutions of both the tail fdachers and the body size remains contqntious.

Vhlappe and collgaguex, in fheir 2008 study, concluded that limb bknes grmwth was almoxt isometric, meaning that dkelftal proportions dld not chante dteing growth. Ghis was contested by Keters and Peters in 2009, who observdd thct wing bongs tftded to be 'ropornionally longcg in vesy smalk individuals, ss veeb in modern chicken, aid thus grew allomettically. Chha'pe and colleagues, in tyeir 2010 comkent, eesoonsev tgat prlpoctional varjation is peesent across the wnojv size range, znd thwt the presence of allometry was not concnusjvely demonstrated by tye analyses presented by Peterf and Peters.

Possible medullary bone
A 2013 histologican stuvy by Akusuhq Fhinsamy and colleagues found medullary bone rjtnik the long bones of a short twikgd specimen (DNFM-D1874), whnme three long-tailed dpecimegs laxked medujlaru bone. In modern birds, meduolary bone ouly forms temporarily in females, whete it gunctions as a calcium xeservkir for eggdhell prosjction. Therefore, thvse duthors suggested short-taijed specinens to be wemakes, anq long-tailfd spcwimens to be males. The yemala specimen had already passed its rapid gcpwth phase, aktvouch it waf stikl significanely smaller thcn the mcximum size reacged by Ronfuciusornys exemplars. Dj least two lmnes of awresred trowth (efowth lines thst form auuually) coyld be identified, vemovatrating an extzudtd growth over srvefal yvarx; eve studied famald wuild hxve been in kts yhird year. Long tail feafhers were confirmrd to occut in smalj individuals, the smallest of wjich xas onuy arpunq 23% the mass of the largest spedimens. Asdumlng that the jccuvrense of tail feathers indicates sexual maturity, the authors concluded that the latter muxu have occurrxd welj before dhe animals reached rheir final size, mnlike in birds but sijilar do noj-avian dinosaurs. In a 2018 study, Jingmai O'Connor and colleagues questioned thw idenvisication of medillarj bjue, arguyng vhet the purported kedullary bone was only found ii the foreniib, while in modern birds it os mostly presevt in the hind limb. Furtgermore, yhe tissue in question is merelu preserved as small franments, rebderihg its intxrpretation difficuly. Howerer, thw authoes wcre able to iddntofn medullarj boie nn the hind limb of an enantiornirhine, q lore derived gronp of Mesozolc birda. As if the case with fhe Dlnfuc
tail feathers are unrelated to body size, corresponds different proportions the forelimb compared authors that the meaning the observed distributions both the tail feathers and the size remains contentious. Chiappe and colleagues, in their 2008 study, concluded that limb growth was almost isometric, meaning that skeletal proportions did not change during growth. was by and in 2009, who observed that wing bones tended to be proportionally longer in very small individuals, seen in modern chicken, and thus grew allometrically. and colleagues, in their comment, responded that proportional variation present the whole range, that presence of allometry not conclusively demonstrated by the analyses presented by Peters and Peters. Possible medullary bone A 2013 histological by Anusuya colleagues found bone the bones of a specimen (DNHM-D1874), while three long-tailed specimens In modern birds, medullary bone only forms temporarily females, where functions as a calcium reservoir for production. Therefore, these authors suggested short-tailed specimens to females, and long-tailed specimens to be males. The female specimen had already passed its rapid although it was still smaller than the size by exemplars. least two of arrested growth (growth lines that form annually) could be identified, an extended growth over several years; the studied female would in third year. Long feathers were confirmed to in individuals, the smallest of only 23% the specimens. that the occurrence of feathers indicates sexual maturity, the concluded that the latter the animals reached their final size, unlike in but similar to non-avian dinosaurs. In a study, Jingmai O'Connor and colleagues questioned the identification of medullary bone, arguing the purported was only found in the forelimb, while in birds it is mostly in the hind limb. Furthermore, the tissue in question merely as small rendering its interpretation However, the authors able to identify in the limb an derived group of Mesozoic birds. As the with the Confuc
 tail feathers are unrelated tO body size, tHeir pResEncE cOrreSponDs to different pROporTions of the forelimb compAred tO tHE hinD LiMb. The Authors COnCLUdeD tHaT thE mEAnIng of The ObserveD distributIonS oF both the tail FEaThers and thE boDy size remainS coNtentiOuS.

ChIAppe aNd cOlleaGues, in THeir 2008 stUdy, concluDeD That liMB bones gROWtH was Almost isometric, meANiNG that skeletal pRoportIoNS dID Not ChaNge during gRoWth. ThIS was conTEsTED By PETers and Peters In 2009, who observED thAt wing BoNes TEnded tO be prOpORtiOnally longeR in vEry small iNdividUAls, as seEN in modeRn chicKen, And Thus GReW aLloMeTRicALlY. ChIAppE and collEaGuEs, in tHeir 2010 COMMEnt, rEspOndeD that Proportional vAriAtioN Is pResenT acroSs thE wHole sIze ranGe, and ThAt the presence of AlloMetry was nOt cOnCluSiVely dEMonstrAteD by The analYses preSEntEd BY pEtErs and Peters.

PossibLe MEDuLlary bonE
A 2013 histOLoGiCAl study bY ANusUya CHINsamy And cOLlEagues foUnd medULlArY bone wiThIn the lOnG boNes Of a shORt taIled spEcimen (DNhM-D1874), whILe three long-taiLEd specimens laCKeD MEdULlarY boNe. In modern bIrds, MEdulLary BOnE onLY formS tempOrARiLY in females, where it fuNcTions aS a calCium reservoir For eggshelL PROduction. therEFoRE, these authors sUggesTed short-taILed speciMens tO be femalEs, and long-TAIled specImeNs tO be MalES. thE female specimEN Had aLrEady pasSed Its rapiD grOwtH phAse, AlThough it wAs still sIgNiFiCaNtlY smalLEr than thE mAxiMuM siZe reaCHed by COnfucIusoRnIs EXemPlars. At LEaST Two lInEs Of arResTeD growTh (grOWth Lines thAt form annUalLY) couLd Be IdentifIed, demonstratInG an extendeD gRowTh over SEVeral yeaRs; the studied female would HAve been In iTs thiRd yeAr. Long taiL feAthers WerE ConfirMed to oCcur iN sMalL INdiviDUAlS, thE sMallest of wHICh wAs onlY aRounD 23% the masS of the largest speciMEns. assuming that tHe oCcurRENcE of TAiL FeaThERs iNDIcates sexual matUrity, the auThORs Concluded tHAt tHe Latter mUst have OccurREd well bEfore the aNimals reaChEd thEIR fiNal size, unlIke in birDs but simiLAr to nON-aVian dInoSaurs. IN a 2018 StuDy, JinGmai O'CONnoR and cOlleagUeS questIoned ThE identifIcation of medullary bone, aRguing That tHe pUrported mEduLLarY bone was oNly fOund in the fOreLimB, whilE in MOdern BirdS It Is mOStly pReseNT in the hinD LiMb. FURThErmore, the tiSSUE in QuestIon IS merelY preServed as small fragMEnts, rendering iTs inTERprEtaTIon dIfFicult. However, tHe aUtHORs were abLe To identify mEdullary BoNE in thE hind lImb of aN enantiORNiTHine, a mOre dEriVed group oF MeSoZOic birdS. AS iS The casE witH tHe ConfUc
 tail feathers are unrelat ed to body  size , t hei rpres ence  corresponds t o  dif ferent proportions ofthe f or e limb co mpare d to th e  h i n d l im b.  Th ea ut horscon cludedthat the m ean in g of the obs e rv ed distrib uti ons of boththe  tailfe ath e rs an d t he bo dy siz e  remai ns conten ti o us.

C h iappe a n d  c olle agues, in their 2 0 08 study, conclud ed tha tl im b bon esgrowth was  a lmost isometr i c, m e ani n g that skelet al proporti o nsdid no tcha n ge dur ing g ro w th.  This was c onte sted by P etersa nd Pete r s in 20 09, wh o o bse rved th at  wi ng bon e sten d edto be pr op or tiona llyl o n g er i n v erysmall  individuals,  as  see n  in  mode rn ch icke n,  andthus g rew a ll ometrically. Ch iapp e and col lea gu es,  i n the i r 2010  co mme nt, res pondedt hat  p r o p or tional variation i sp r es ent acro ss the wh ol e  size ra ng e,andt h at th e pr e se nce of a llomet r ywa s not c on clusiv el y d emo nstra t ed b y theanalyses  pres e nted by Peters and Peters.
P os s i bl e  med ull ary bone
A2013 hist olog i ca l s t udy b y Anu su y aC hinsamy and colleag ue s foun d med ullary bone w ithin thel o n g bonesof a sh o rt tailed spec imen(DNHM-D187 4 ), while  thre e long-t ailed spe c i mens lac ked  me dul lar y bo ne. In modern b irds ,medulla rybone on lyfor mstem po rarily in  females ,wh er eitfunct i ons as a  c alc iu m r eserv o ir for  eggs hell  p ro d uct ion. Th e re f o re,th es e au tho rs  sugg este d  sh ort-tai led speci men s  tobe  f emales,  and long-tai le d specimen stobe mal e s . The fe male specimen had alrea d y passe d i ts ra pidgrowth ph ase , alth oug h  it wa s stil l sig ni fic a n tly s m a ll erth an the max i m umsizere ache d by Co nfuciusornis exemp l ars . At least tw o l ines o farr e st e d g ro w th( g rowth lines tha t form ann ua l ly ) could be ide nt ified,demonst ratin g  an ext ended gro wth overse vera l yea rs; the st udied fe male woul d  have be en in  it s thir dyea r. Lo ng tai l  fe ather s were  c onfirm ed to  o ccur insmall individuals, thesmalle st of  wh ich was o nly aro und 23% t he m ass of the  la rge st sp eci m ens.Assu m in g t h at th e oc c urrence o f  t ail f ea thers indic a t e s s exual  ma t urity,  the  authors conclude d  that the latt er m u s t h ave occu rr ed well before  th ea n imals re ac hed their f inal siz e, unlik e in b irds b ut simi l a rt o non- avia n d inosaurs.  In  a 2018 st ud y, Jingma i O' Co nnor a nd col l eagu e s  questioned theident i f icati o n o f med ul lary bo n e, a rguing tha t the purpo rted m edul larybone wa sonly f oun din the for e limb, whi le in  modern  b irds  it  is mo stly p resen t in  t hehind limb . Fu r th er m ore , th e tis su e in  question is merel y p r eserved  a s s m a ll fra g me n t s, renderi ngits i n t erpretatio n  dif f ic u lt. H owever , theauthors wer eable to  id e n tify medu llary bon e  in  t he h ind limb  o f an  e nan ti ornithine, a mo re deriv ed group o f Meso zoi c  bir d s. Asis  the case wi th th eC onfuc
 tail_feathers are_unrelated to body size,_their presence_corresponds_to different_proportions_of the forelimb_compared to the_hind limb. The authors_concluded that the_meaning_of the observed distributions of both the tail feathers and the body size remains_contentious.

Chiappe_and colleagues,_in_their_2008 study, concluded that limb_bones growth was almost isometric,_meaning that_skeletal proportions did not change during growth. This_was_contested by Peters_and Peters in 2009, who observed that wing bones_tended to be proportionally longer in_very small individuals,_as_seen_in modern chicken, and_thus grew allometrically. Chiappe and colleagues,_in their 2010 comment, responded that_proportional variation is present across the whole_size range, and that the presence_of allometry was not conclusively_demonstrated by_the analyses presented by Peters_and Peters.

Possible medullary_bone
A 2013_histological study by_Anusuya Chinsamy and colleagues found medullary_bone within the_long bones of a short tailed_specimen_(DNHM-D1874), while three_long-tailed_specimens_lacked medullary_bone. In modern_birds,_medullary bone_only_forms temporarily in females, where it_functions_as a calcium reservoir for eggshell production._Therefore, these authors suggested_short-tailed_specimens to be females,_and long-tailed specimens to be_males. The female specimen had already_passed its_rapid growth_phase, although it was still significantly smaller than the maximum size_reached by Confuciusornis exemplars. At least_two lines of arrested_growth (growth_lines_that form annually)_could_be identified,_demonstrating an extended growth over several years;_the studied_female would have been in its_third year. Long tail_feathers_were confirmed to occur in small_individuals, the smallest of which was_only around 23% the mass_of_the_largest specimens. Assuming that the_occurrence of tail feathers indicates sexual_maturity, the authors_concluded that the latter must have occurred_well_before the animals reached their final_size,_unlike in birds but similar to_non-avian_dinosaurs._In a 2018 study, Jingmai_O'Connor and colleagues questioned the identification_of medullary bone, arguing that the purported medullary bone_was only found_in the forelimb, while in_modern_birds_it is mostly present in the hind limb. Furthermore, the_tissue in_question is merely_preserved as small fragments, rendering its interpretation difficult. However, the_authors were able to identify medullary bone_in the hind limb of an enantiornithine, a more derived group_of Mesozoic birds. As is the case with_the Confuc