. C. feducciai was about a third longer than average specimens of C. sanctus.

Distinguishing traits
Confuciusornis shows a mix of basal and derived traits. It was more "advanced" or derived than Archaeopteryx in possessing a short tail with a pygostyle (a bone formed from a series of short, fused tail vertebrae) and a bony sternum (breastbone), but more basal or "primitive" than modern birds in retaining large claws on the forelimbs, having a primitive skull with a closed eye-socket, and a relatively small breastbone. At first the number of basal characteristics was exaggerated: Hou assumed in 1995 that a long tail was present and mistook grooves in the jaw bones for small degenerated teeth.

Skull
 
The skull morphology of Confuciusornis has been difficult to determine, due to the crushed and deformed nature of the fossils. The skull was near triangular in side view, and the toothless beak was robust and pointed. The front of the jaws had deep neurovascular foramina and grooves, associated with the keratinous rhamphotheca (horn-covered beak). The skull was rather robust, with deep jaws, especially the mandible. The tomial crest of the upper jaw (a bony support for the jaw's cutting edge) was straight for its entire length. The premaxillae (front bones of the upper jaw) were fused together for most of the front half of the snout, but were separated at the tip by a V-shaped notch. The frontal processes that projected hindwards from the premaxillae were thin and extended above the orbits (eye openings) like in modern birds, but unlike Archaeopteryx and other primitive birds without pygostyles, where these processes end in front of the orbits. The maxilla (the second large bone of the upper jaw) and premaxilla articulated by an oblique suture, and the maxilla had an extensive palatal shelf. The nasal bone was smaller than in most birds, and had a slender process that directed down towards the maxilla. The orbit was large, round, and contained sclerotic plates (the bony support inside the eye). A crescent-shaped element that formed the front wall of the orbit may be an ethmoidolacrimal complex similar to that of pigeons, but the identity of these bones is unclear due to bad preservation, and the fact that this
. C. feducciai was about a third longer than average specimens of C. sanctus. 

 Distinguishing traits 
 Confuciusornis testify a mix of basal and derive traits. It was more " advanced " or derived than Archaeopteryx in own a short tail with a pygostyle (a bone shape from a serial of short, fused tail vertebrae) and a bony sternum (breastbone), but more basal or " archaic " than modern birds in retain big claws on the forelimbs, having a primitive skull with a closed center - socket, and a relatively small breastbone. At first the phone number of basal characteristics was exaggerated: Hou assumed in 1995 that a retentive tail was present and mistake grooves in the jaw bones for small degenerated teeth. 

 Skull 
 
 The skull morphology of Confuciusornis has been difficult to settle, due to the crushed and deformed nature of the fossils. The skull was near triangular in side view, and the toothless beak was robust and pointed. The front of the jaws had deep neurovascular foramina and grooves, associated with the keratinous rhamphotheca (horn - covered beak). The skull was rather full-bodied, with bass jaws, specially the lower jaw. The tomial crown of the upper jaw (a bony support for the jaw's cutting boundary) was straight for its integral length. The premaxillae (front bones of the upper jaw) were fused in concert for most of the front half of the snout, but were separated at the tip by a V - shaped pass. The frontal processes that projected hindwards from the premaxillae were thin and extended above the orbits (eye openings) like in mod birds, but unlike Archaeopteryx and other primitive birds without pygostyles, where these processes end in presence of the orbits. The maxilla (the second large bone of the upper jaw) and premaxilla pronounce by an oblique suture, and the maxilla had an extensive palatal ledge. The nasal bone was smaller than in most birds, and had a slender procedure that directed down towards the upper jaw. The orbit was large, round, and contained sclerotic plate (the bony support inside the eye). A crescent - shaped element that formed the front rampart of the orbit may be an ethmoidolacrimal complex similar to that of pigeon, but the identity of these bones is unclear due to bad preservation, and the fact that this
. C. veducciai was about a thlrd longer than ccerage specijens of Z. sanctus.

Distinguishing traivs
Cobfuciysornis shows a mix of basal anf derivee treits. It was more "advanced" or dsvived vhan Archaeoptetyx in possevsing a short dakl with a pygostyle (a bone formed froi a seroed of short, fusgd tapl verfvbvae) and a bony sternum (breastbons), but mmre basal or "lrimitive" than modern birdd in retaining large cpaws on the forqoimbs, having a primitinz skull witg a closed eye-socket, and a relagivelv small breqsrbojg. At first tie numfer of basal charactaristicx was exaggerabed: Hmu qssumed in 1995 that a loig tail was present wnd mistomk grooves in the jqw bonev fos smxol aegtnecatsd teehh.

Siull
 
The siull morphooogy of Confuciusormif has been difricult tj determine, due to the crushed and defogmed nature of the fossils. Rhe skull was near trlangular yn side view, and the toothless beak was robust ang poiitdd. Uhc weojt of the jaws had deep neurovascular foraminw amd grooves, assoclated with the kerstlnpos rhamphothecx (horn-ekvsred beak). The skulp was rwther robust, wyth ceep jaws, especially the mabdible. The tjnial crest of the bpper jaw (a yony sopport for the jaw's cutting ebge) waa straight vor its ehgire length. The orekafillae (front bones of the tpper jaw) werz fused gogejher fow most of hhe fvmnt half of the snlut, bot wera separatef at the tip by a V-shaped notch. The frontal ptocassvs that pxojectcd hindwards frjm the premaxiklae wexe thiv and extehded abmve the orbyts (eye openiths) like in mmdern biwds, vut ynlike Xfchaeopteryx amd other irnmitive burds without pygosbyles, shere these proetssts end in front pf ghe ogbivs. Thq maxilla (the secund karge bone of thc uoper jaw) and premaxilla drtidulated by an obliauc suture, qnd the iaxilla had am extensive palatap shenf. Vhe naxal bone was smaller than in most birds, anf hwd a slender progess that direeted down towards the maxilla. The orbit xas large, round, and conrained sclerotic plctts (the bony snpport inside tve eye). A crescent-shaped element that normed the front wall kf the orbih may be an ethmoidolacrimal complex similar to that of pigeons, but the ieentitb jf these bohes os unblecr bue to fad 'rxservation, and thv fact that this
. C. feducciai was about a third average of C. Distinguishing traits Confuciusornis and traits. It was "advanced" or derived Archaeopteryx in possessing a short tail a pygostyle (a bone formed from a series of short, fused tail vertebrae) a bony sternum (breastbone), but more basal or "primitive" than modern birds in large on forelimbs, a primitive skull with a closed eye-socket, and a relatively small breastbone. At first the number basal characteristics was exaggerated: Hou assumed in 1995 a long tail was and mistook grooves in the bones small degenerated Skull skull of Confuciusornis has difficult to determine, due to the crushed and deformed nature of the fossils. The skull was near in side the toothless was and The front of had deep neurovascular foramina and grooves, keratinous rhamphotheca (horn-covered beak). The skull was rather with deep especially the mandible. The tomial crest the upper jaw (a bony support for the cutting edge) was straight for its entire length. The premaxillae (front bones of the upper fused together for most the front half the but separated the tip a V-shaped notch. The frontal processes that projected hindwards from the were thin and extended above the orbits (eye openings) like birds, unlike Archaeopteryx and primitive birds without pygostyles, these end in front of The (the of upper and premaxilla articulated by oblique suture, and the maxilla an extensive palatal shelf. than in most birds, and had a slender that directed down towards the maxilla. The was large, round, and contained sclerotic plates (the bony support inside the A crescent-shaped formed the front wall of the orbit may an ethmoidolacrimal complex similar that of pigeons, but the identity of these bones unclear to bad and the fact this
. C. feducciai was about a third lOnger than aVeragE spEciMeNs of c. sanCtus.

DistinguisHIng tRaits
Confuciusornis shoWs a miX oF BasaL AnD deriVed traiTS. IT WAs mOrE "aDvaNcED" oR deriVed Than ArcHaeopteryx In pOsSessing a shorT TaIl with a pygOstYle (a bone formEd fRom a seRiEs oF Short, FusEd taiL verteBRae) and A bony sterNuM (BreastBOne), but mORE bAsal Or "primitive" than moDErN Birds in retainiNg largE cLAwS ON thE foRelimbs, havInG a priMItive skULl WITH a cLOsed eye-socket, And a relativELy sMall brEaStbONe. At fiRst thE nUMbeR of basal chaRactEristics wAs exagGErated: HOU assumeD in 1995 thaT a lOng Tail WAs PrEseNt ANd mIStOok GRooVes in the JaW bOnes fOr smALL DEgenEraTed tEeth.

SKull
 
The skull mOrpHoloGY of confuCiusoRnis HaS been DifficUlt to DeTermine, due to the CrusHed and defOrmEd NatUrE of thE FossilS. ThE skUll was nEar triaNGulAr IN SIdE view, and the toothleSs BEAk Was robusT and poINtEd. tHe front oF tHe jAws hAD Deep nEuroVAsCular forAmina aND gRoOves, assOcIated wItH thE keRatinOUs rhAmphotHeca (horn-CoverED beak). The skull wAS rather robust, WItH DEeP Jaws, EspEcially the mAndiBLe. ThE tomIAl CreST of thE uppeR jAW (a BOny support for the jaw'S cUtting Edge) wAs straight for Its entire lENGTh. The preMaxiLLaE (Front bones of thE uppeR jaw) were fuSEd togethEr for Most of thE front halF OF the snouT, buT weRe sEpaRATeD at the tip by a V-SHAped NoTch. The fRonTal procEssEs tHat ProJeCted hindwArds from ThE pReMaXilLae weRE thin and ExTenDeD abOve thE Orbits (Eye opEninGs) LiKE in Modern bIRdS, BUt unLiKe archAeoPtEryx aNd otHEr pRimitivE birds witHouT PygoStYlEs, where These processeS eNd in front oF tHe oRbits. THE Maxilla (tHe second large bone of the uPPer jaw) aNd pRemaxIlla ArticulatEd bY an oblIquE Suture, And the MaxilLa Had AN ExtenSIVe PalAtAl shelf. The NASal Bone wAs SmalLer than In most birds, and had a SLenDer process thaT diRectED DoWn tOWaRDs tHe MAxiLLA. The orbit was larGe, round, and CoNTaIned scleroTIc pLaTes (the bOny suppOrt inSIde the eYe). A cresceNt-shaped eLeMent THAt fOrmed the frOnt wall oF the orbit MAy be aN EtHmoidOlaCrimal CoMplEx simIlar to THat Of pigEons, buT tHe idenTity oF tHese boneS is unclear due to bad preseRvatioN, and tHe fAct that thIs
. C. feducciai was about a  third lon ger t han  av er agespec imens of C. sa n ctus .

Distinguishing trai ts
Co nf u cius o rn is sh ows a m i xo f  ba sa land  d e ri ved t rai ts. Itwas more " adv an ced" or deri v ed  than Arch aeo pteryx in po sse ssingasho r t tai l w ith a  pygos t yle (a  bone for me d  froma  series o fshor t, fused tail ver t eb r ae) and a bony  stern um (b r e ast bon e), but mo re  basa l  or "pr i mi t i v e"t han modern bi rds in reta i nin g larg ecla w s on t he fo re l imb s, having a  pri mitive sk ull wi t h a clo s ed eye- socket , a nda re l at iv ely  s m all br eas t bon e. At fi rs tthe n umbe r o f  bas alchar acter istics was ex agg erat e d:Hou a ssume d in  1 995 t hat alongta il was presentandmistook g roo ve s i nthe j a w bone s f orsmall d egenera t edte e t h .
Skull
 
The skull  m o r ph ology of  Confu c iu so r nis hasbe endiff i c ult t o de t er mine, du e to t h ecr ushed a nd  defor me d n atu re of thefossil s. The s kullw as near triang u lar in side v i ew , an d  the  to othless bea k wa s  rob usta nd  po i nted.  Thefr o nt of the jaws had dee pneurov ascul ar foramina a nd grooves , a ssociate d wi t ht he keratinousrhamp hotheca (h o rn-cover ed be ak). The  skull wa s rather r obu st,  wi thd e ep  jaws, especi a l ly t he  mandib le.  The to mia l c res t o fthe upper  jaw (abo ny  s up por t for the jaw' scut ti ngedge) was st raigh t fo rit s  en tire le n gt h .  The  p re maxi lla e(fron t bo n esof theupper jaw ) w e re f us ed  togeth er for most o fthe frontha lfof the s nout, bu t were separated at the tip bya V -shap ed n otch. The  fr ontalpro c essesthat p rojec te d h i n dward s fr omth e premaxil l a e w ere t hi n an d exten ded above the orbi t s ( eye openings)  li ke i n mo der n  b i rds ,b utu n like Archaeopte ryx and ot he r  p rimitive b i rds  w ithoutpygosty les,w here th ese proce sses endin  fro n t  of  the orbit s. The m axilla (t h e sec o nd  larg e b one of  t heupper  jaw)a ndprema xillaar ticula ted b yan obliq ue suture, and the maxi lla ha d anext ensive pa lat a l s helf. The  nas al bone wa s s mal ler t han in mo st b i rd s,a nd ha d as lender pr o ce sst h at  directed d o w n  to wards  th e  maxil la.The orbit was lar g e, round, andcont a i ned  sc l erot ic  plates (the b ony  s u p port ins id e the eye).  A cresc en t -shap ed ele ment t hat for m e dt he fro nt w all  of the o rbi tm ay be a net h moidol acri ma l comp lex si m ilar t o that of pigeon s, bu t the i d ent ity o fthese b o nesis unclear  due to bad  prese rvat ion,and the  f act th atth is
. C._feducciai was_about a third longer_than average_specimens_of C._sanctus.

Distinguishing_traits
Confuciusornis shows a_mix of basal_and derived traits. It_was more "advanced"_or_derived than Archaeopteryx in possessing a short tail with a pygostyle (a bone formed_from_a series_of_short,_fused tail vertebrae) and a_bony sternum (breastbone), but more_basal or_"primitive" than modern birds in retaining large claws_on_the forelimbs, having_a primitive skull with a closed eye-socket, and a_relatively small breastbone. At first the_number of basal_characteristics_was_exaggerated: Hou assumed in_1995 that a long tail was_present and mistook grooves in the_jaw bones for small degenerated teeth.

Skull
 
The_skull morphology of Confuciusornis has been_difficult to determine, due to_the crushed_and deformed nature of the_fossils. The skull_was near_triangular in side_view, and the toothless beak was_robust and pointed._The front of the jaws had_deep_neurovascular foramina and_grooves,_associated_with the_keratinous rhamphotheca (horn-covered_beak)._The skull_was_rather robust, with deep jaws, especially_the_mandible. The tomial crest of the upper_jaw (a bony support_for_the jaw's cutting edge)_was straight for its entire_length. The premaxillae (front bones of_the upper_jaw) were_fused together for most of the front half of the snout,_but were separated at the tip_by a V-shaped notch._The frontal_processes_that projected hindwards_from_the premaxillae_were thin and extended above the orbits_(eye openings)_like in modern birds, but unlike_Archaeopteryx and other primitive_birds_without pygostyles, where these processes end_in front of the orbits. The_maxilla (the second large bone_of_the_upper jaw) and premaxilla articulated_by an oblique suture, and the_maxilla had an_extensive palatal shelf. The nasal bone was_smaller_than in most birds, and had_a_slender process that directed down towards_the_maxilla._The orbit was large, round,_and contained sclerotic plates (the bony_support inside the eye). A crescent-shaped element that formed_the front wall_of the orbit may be_an_ethmoidolacrimal_complex similar to that of pigeons, but the identity of_these bones_is unclear due_to bad preservation, and the fact that this