Reviews

EDITED BY REBECCA L. HOLBERTON

Thefollowing critiques express the opinions of the individual evaluators regarding the strengths, weaknesses,and value of thebooks they reviem As such,the appraisals are subjective assessments anddo not necessarilyreflect the opinions of theeditors or anyofficial policy of theAmerican Ornithologists'Union.

The Auk 117(3):836-839, 2000

Anatomy and Systematicsof the Confuciusorni- papermay be interpretedto the contrary,so to this thidae (Theropoda: Aves) from the Late Mesozoic reviewer the issue remains unresolved. of NortheasternChina.--L. M. Chiappe, S. Ji, Q. Ji, Most of this publicationconsists of descriptive and M. A. Norell. 1999. Bulletin of the American Mu- anatomy,which had been treatedin at least eight seum of Natural History, Volume 242. 89 pp. ISSN shorterpapers on Confuciusornisby other authors. In- 0003-0090.Paper, $8.60.--Only a few yearsago, the stead of summarizing this literature, however, fossilrecord for the earliestknown period in theevo- Chiappeet al. haveselectively chosen from it various lution of birds was depressinglymeager. From the pointsof whichto be critical,even when the view in lateJurassic Archaeopteryx to the lateCretaceous Hes- questionmay not be the mostcurrent. Such selectiv- perornisand Ichthyornis,only scrappyavian remains ity, apartfrom being disingenuous, detracts from the were known. This changeddramatically with the usefulness of the work as a whole, which cannot be discoveryof birds in early Cretaceouslake deposits relied upon to supercedethe earlier literature.For in Spain and particularlyin northeasternChina's example,Hou et al. (1999)are citedonly to saythat LiaoningProvince, where thousands of fossilshave Chiappeet al. were"unable to examinethe recently been recovered,including several different kinds of describedConfuciusornis dui." Yet,nowhere is it men- birds. Incredible as it once would have seemed, one tionedthat the main importanceof this specimenis that it preservesthe hornyrhamphotheca. Likewise, of theseearly Cretaceousbirds, Confuciusornissanc- Chiappeet al. sparenothing to reproduceand criti- tus,is now known from hundredsof specimens. cize an outdatedreconstruction by Hou et al. (1996), The work reviewed here has the superficialap- madewhen only a few incompletespecimens of Con- pearanceof a monographictreatment of Confuciusor-fuciusornis existed, but they neverallude to the pre- his and its relatives.Unfortunately, it is not. The au- posterousreconstruction on the cover of Scientific thors, steeped in cladistic fundamentalism,have Americanthat accompaniedan articleby Padianand beenamong the moreinsistent proponents of the or- Chiappe (1998)in which Confuciusornisis depicted igin of birds from theropoddinosaurs, with its at- like somemedieval rendition of a dyspepticphoenix tendantcorollaries, such as the originof flight from that had just dismountedfrom a horse. the groundup. The presentwork appearsto be but It had previouslybeen determined that the skullof an attemptto put a dinosaurian"spin" on the still- Confuciusornisexhibits the primitive diapsidcondi- emerginginterpretations of the significanceof Con- tion and, in a separatesection on kinesis (pp. 72-75), fuciusornis. Chiappeet al. arguethat the skullwas akinetic. Food Mostof the specimensfrom the Liaoningdeposits processingby a toothlessbird with an akineticskull were collected,and to someextent prepared, not by would be highly problematic,so a more detailed scientists,but by thoseintent on sellingthe speci- study of the wealth of specimenspotentially avail- mens,so that the possibilityof artificial "enhance- ablewill morelikely showthat the skull wasin fact ment"of fossilsis ratherhigh. Indeed, Chiappe et al. kinetic. (p. 68, figures 60 to 63) note several specimensof No onehad detecteduncinate processes on theribs Confuciusorniswith partsglued on from otherindi- in anyof the specimensof Confuciusornishitherto ex- vidualsor with structuresthat havebeen sculpted amined. Nor do these processesoccur in Archaeo- out of matrix with a binder.It has also been sug- pteryxor othervery early birds. Supposeduncinate gestedthat the otherwiseinexplicable proximal hu- processeshave recently been reportedin late Creta- meral foramen of Confuciusornisis an artifact. Al- ceoustheropods, however (Clark et al. 1999).If they thoughChiappe et al. denythis, information in their are invariably absentin late Jurassicand early Cre-

836 July2000] Reviews 837 taceousbirds, it would suggestto any reasonable of the outermostprimary feathers.Regrettably, in personthat the structuresare unlikelyto be homo- noneof their photographsare all of the elementsof logousbetween birds and dinosaurs.Therefore, for the hand of Confuciusornisclearly displayed,and advocatesof the theropodorigin of birds, it would thereis no interpretivediagram of the hand. be desirableto find uncinateprocesses in early birds Vazquez(1992) identified a number of specializa- or to wishtheir absenceaway. Chiappe et al. do both. tions of the wrist in all modern birds that he consid- They illustrate(figure 34) what they claim to be un- ered to be necessaryfor flappingflight. He suggest- cinateprocesses articulating with six ribs in only a ed that the wrist in Archaeopteryx"was probablyin- singlespecimen of Confuciusornis,from which they capableof executingthe kinematicsof modernavian go on to speculate"that their absencein otherbasal poweredflight." Becausethis hasbeen seized upon birds... may be due to preservationalfactors or on- as supportingthe "ground up" theory of the origin togeneticdevelopment" (pp. 32-33). This goesbe- of flight, what bearingdoes the morphologyof the yondspecial pleading, because the authorscould not wrist of Confuciusornishave on thisquestion? Chiap- possiblybelieve that this would explainthe absence peet al. do not cite Vazquezand do not addressthis of uncinateprocesses in all of the specimensof Ar- issue.They describe the ulnare (which nowhere is la- chaeopteryxor in any of the hundredsof otherspec- beled in their illustrations)as much smaller than the imens of Confuciusornis. radiale, a condition unlike modern birds. Another As shown(fig. 34), the so-calleduncinate process- importantdifference is that the alular metacarpalis esoriginate only on theposterior six ribs, whereas at notfused to themajor metacarpal, and the major and least two strong ribs anterior to thesedo not have minor metacarpalsare not fused distally. Therefore, processes,which would be unlike any known bird. it seemssafe to saythat Confuciusornisdid not have Also, "the uncinate processesare long and extend all of the adaptationsof the modernavian wrist. over nearly two subsequentribs" (p. 32), an utterly One aspectof its wrist must havebeen as well de- unheardof condition.And judgingfrom the illustra- velopedas in modernbirds, however,as inadver- tion, some of the ribs must have had two tmcinate tently demonstratedin figure70, which showsa re- processes,which is evenmore implausible.Clearly, constructedskeleton of Confuciusorniswith the shad- thesecannot be uncinateprocesses and are probably ed outline of the body and wings. Here the hand is displacedgastralia or ribs that havebeen misrepre- shownextending down at an angleof about45 ø from sentedto servea larger purpose. the horizontal.In this position,had the bird beenter- The furcula of Confuciusornisis large and robust restrial, as the authorswould prefer, its long pri- and the scapula and coracoid are fused; "conse- maries would have been pressed down and bent quently,the acrocoracoidprocess is not developed" againstthe surfaceof the ground. Instead,the pri- (p. 29). Therefore,the shouldergirdle is more like mariesare shownprojecting straight back, horizon- that of Archaeopteryxthan that of modernbirds. The tally, as thoughthey were comingoff the ulna per- sternumis a large ossifiedplate but lacksan ossified haps. Thus, it can be seenthat with its very long carina. From this osteologicalevidence, it is clear wing, whetherit cameto rest on the groundor on a that the supracoracoideusmuscle was not function- tree limb, Confuciusornishad to be able to flex the ing as a dorsalelevator in Confuciusornis.The lack of wrist to the samedegree as in modernbirds to keep an acrocoracoidprocess and other adaptationsfor its primariesclear of the substrate. the supracoracoideusto functionas a dorsalelevator The pelvishas the avian retropubicconstruction, were among the main evidenceused by Ostrom but with the primitivecondition of havingthe pubes (1976) and othersto argue that Archaeopteryxwas at fused distally. The tarsometatarsusis short and best a poor flier or even a "pre-flight" stagein the squat,much shorterthan the tibiotarsusor femur, evolutionof avian flight. Chiappeet al. do not men- which is very unlike any truly terrestriallyadapted tion any of this in connectionwith Confuciusornis,birds and militatesagainst any interpretationof this however. bird being at all cursorial. The humerusis robust,with a very largepectoral Perhapsthe mostspectacular aspects of Confucius- crest.It is slightly longerthan the radius and ulna, ornis are revealedby the preservationof feathers and the hand is muchlonger than either the forearm with the skeleton.These indicate that the wing was or the humerus.Chiappe et al. (p. 33) considerthis extremelylong and pointed,with the primarieshav- to be "clearlyprimitive" but do notexplain their rea- ing veryasymmetrical vanes. There was, however, no soning. alula on the outer digit, whereasthe alula has been Thehand consists of threedigits, the outerand in- argued as being necessaryfor avian flight at low ner of which bear large, recurvedclaws with large speedwith high maneuverability(Sanz et al. 1996). flexor tubercles.The ungual phalanx of the major Someindividuals of Confuciusornis(Chiappe et al. (middle) digit is reducedand is not clawlikein form. do not indicate what proportion; Feduccia [1999] Althoughthe authorsmake no interpretationof this says5 to 10%)have two extraordinarilylong central condition,it is likelythat it reflectsthe increasing im- tail featherswith expandedtips that appear to be portanceof the majordigit as the site of attachment nearly 2.5 times the length of the body (fig. 48). 838 Reviews [Auk, Vol. 117

Chiappeet al. maintainthat all the otherrectrices of few measurementsfor four specimens(Tables I and Confuciusornisare decomposedand hidden among 2). The measurementsof the humeri and femora of the feathersof the rump.Yet, Hou et al. (1996)show theseare repeatedin Table4 (we can take comfort a specimenwith apparentlynormally developed rec- that they are the samein both places),along with trices,which would certainlyaccord better with the thoseof nine otherspecimens. There is no analysis well-developedpygostyle. So what are we to believe? to determine whether size variation is a continuum Regardlessof what the factsmay prove to be, this or bimodal or has some other distribution. Are the point aloneshould be sufficientto demonstratethat oneswith longtail feathersat the upperend of var- Chiappeet al. havenot dealtadequately either with iation,the lower,or throughoutthe range?Chiappe the existingspecimens or the literature. et al. (p. 4) note that "the high numberof extraor- Theonly other member of theConfuciusornithidae dinarily preservedspecimens affords an unprece- recognizedby Chiappeet al., Changchengornisheng- dentedopportunity to investigateintraspecific vari- daoziensis,is from the same depositsas Confucius- ation,allometric growth, and sexualdimorphism in ornis.This new genusand specieswas describedby one of the earliestand most primitive lineagesof Ji et al. in March 1999. In November 1999 it was com- birds,"but theirown studydoes nothing of thekind. pletely redescribedin the presentwork, which re- The summaryof the systematicsof the Confuciu- peatsall six illustrationsfrom the previouspaper- sornithidae(pp. 68-72) dealsmainly with synony- a rather egregiouscase of "double-dipping."That mizing two otherspecies of Confuciusornisdescribed Changchengornisis a valid genusis highly doubtful. by Hou. There is somediscussion of why previous The only knownspecimen is the holotype,which by authorswere "wrong" in the overall placementof the authors'own admission(p. 50) "has beencom- the Confuciusornithidae,and then the authorspre- pressedand deformed ... and it doesnot provide senttheir cladogramin whichthe family is shownas muchinformation." What is apparentis that it has morederived than Archaeopteryx but thesister-group the samewing shape,the sametwo elongatedrec- to all otherknown birds. No cladisticanalysis is pre- trices,the samedistinctive shape of the humerus, sentedto justify the cladogram,however, and the and the sameoverall proportions of thewing andleg legendrefers to an unpublishedbook. Thus, no jus- as Confuciusornis. tificationis providedin this putative"monograph" At one point (p. 67), Chiappeet al. say of Chang- regardingthe mostimportant systematic conclusion chengornisthat "the phalangeal formula of thefoot is that one would careto know aboutthe family.The typicalof theropoddinosaurs: 2-3-4-5-x .... "Who two additional cladogramsin figure 68 are not dis- do theyexpect to impresswith this choicetidbit? It cussedin the text, and the legendagain refersonly happensto be true,but it is alsotrue that the same to the sameunpublished'book. These cladograms phalangealformula is foundin Confuciusornis(p.47) have no bearingon the systematicposition of Con- and is the typical and primitive conditionfound in fuciusornisand have been inserted only to furtheran- almostall birds.Such gratuitous statements are char- otherhidden agendum that is irrelevantto the pre- acteristicof the propagandizingthat the theropod sent review. proponentsof avianorigin seem to think is necessary The short terminal sectionon "Life-style of the to bolstertheir hypothesis. In the samevein, Chiap- Confuciusornithidae" reveals the true weakness of peet al. refer to the digitsof the hand in the Con- theory-ladenanalyses. The originaldescribers envi- fuciusornithidaewith the theropodanformula of I, sioned Confuciusornisnot only as an arborealbut a II, III, whereasit hasbeen repeatedly shown (Holm- climbingbird. On the otherhand, even thoughmil- gren 1955, Hinchliffe 1985, Burke and Feduccia, lionsof yearshad elapsedsince the time of Archaeo- 1997)and conceded(Wagner and Gauthier 1999) that pteryx,the theropodistsstill seemto want all birds the digitsof the hand in birds are II, III, IV. Because in the early Cretaceousto be terrestrial,as though this is suchcompelling evidence against the thero- this would somehowadd strengthto their requisite pod origin of birds, it is hardly any wonder that "ground-up"theory of avianflight. Based on some Chiappeet al. cannotbring themselvesto use the rather tediousand unconvincingevidence on pro- correct formula. portionsand structureof bonesof the toes,Chiappe One line of evidencesuggesting that Changcheng- et al. arguenot so muchthat Confuciusorniswas ter- ornishengdaoziensis is at leasta valid speciesis thatit restrial,but that it was not arboreal,as thougha ter- appearsto be smaller than Confuciusornissanctus. restrial life-style were the only alternative.This This canbe ascertainedonly by referringto the au- leavesthem with the problemthat Confuciusornis ob- thors'meager tables of measurements,because noth- viously could fly, yet (and they do not make this ing aboutits sizeis discussed.Size is somethingthat point) someaspects of its morphologyare the same the authorsall but ignore.Tremendous size variation asthose used to suggestthat Archaeopteryx could not exists in Confuciusornis--notethe dramatic differ- fly, or at least not fly well. Consequently,they are ence in the two individuals illustrated in the same forced into the assumptionthat Confuciusorniswas slabin figure62--but despitethe factthat hundreds "ableto lift off aftera shorttake off run" (p. 79).Lift of individualsexist, Chiappeet al. provide only a off any time it pleasedwould be morelike it, because July2000] Reviews 839 it is obviousthat Confuciusorniswas neither terres- (M. K. Hecht et al., Eds.). Freunde des Jura-Mu- trial nor arborealin the senseof clamberingaround seum,Eichsffitt, Germany. in trees. The very long pointed wings and highly HOLMGREN,N. 1955. Studieson the phylogenyof asymmetricalvanes of theremiges are those of an ae- birds. Acta Zoologica36:243-328. rially adaptedbird suchas a tropicbird,tern, falcon, Hou, L.-H., L. D. MARTIN, Z. ZHOU, AND A. FEDUC- nightjar,or swallow.The two extremelylong central C•A.1996. Early adaptive radiation of birds: Ev- rectricesof someindividuals make senseonly if used idence from fossils from northeastern China. in aerial display,as are the long rectricesof tropic- Science 274:1164-1167. birds and somenightjars, or in arborealdisplays as Hou, L.-H., L. D. MARTIN, Z. ZHOU, A. FEDUCCIA, in somebirds-of-paradise. AND E ZHANG. 1999. A diapsid skull in a new As Chiappeet al. note(p. 79),the presence of many speciesof the primitivebird Confuciusornis.Na- individuals in a singlelayer over a small area of lake ture 399:679-682. depositsuggests colonial (or at least flocking)be- Ji, Q., L. g. CHIAPPE,AND S.-A. Ji. 1999. A new late haviorand a catastrophicdieoff, perhaps associated Mesozoic confuciusornithid bird from China. with volcanicactivity. I would suggestthat the rea- Journalof VertebtratePaleontology 19:1-7. son Confuciusornisis the mostabundant bird in the OSTr•OM,J. H. 1976. Somehypothetical anatomical depositis becauseflocks of themwere flying overthe stagesin theevolution of avianflight. Smithson- lake when disaster struck. There can be little doubt ian Contributionsto Paleobiology27:1-21. that the principalmeans of locomotionof Confucius- PADIAN,K., ANDL. M. CHIAPPE.1998. On the origin orniswas flight. This is a mostimportant fact because of birds and their flight. ScientificAmerican it wasflying with a primitive,fused scapulocoracoid 278(2):38-47. without an enlargedacrocoracoid process, it wasfly- SANZ, J. L, L. M. CHIAPPE,B. P. PI•REZ-MORENO,A.D. ing without a keeledsternum, it was flying without BUSCALIONI,J. J. MORATALLA,E ORTEGA,AND E an alula,and it apparentlywas flying without a fully J. POYATO-ARIZA.1996. An early Cretaceous modernavian wrist. Confuciusornisshows us, there- bird from Spainand its implicationsfor the evo- fore,that we shouldnot positthe highlyrefined as- lution of avianflight. Nature382:442-445. pects of modern birds as being requisite for active VAZQUEZ,J. R. 1992.Functional osteology of the avi- flappingflight. It alsoremoves virtually all of theob- an wrist and the evolution of flapping flight. jections to Archaeopteryxbeing capable of active Journalof Morphology21:259-268. flight. WAGNER, G. 1ø.,AND J. g. GAUTHIER. 1999. 1,2,3 = Thus, if Chiappe et al. actually understandthe 2,3,4:A solutionto the problemof the homology true significanceof Confuciusornis,then they have of the digits of the avian hand. Proceedingsof done their best to prevent it from being revealed. the NationalAcademy of SciencesUSA 96:5111- Their paper will standas an exemplarof manipula- 5116. tion of information to conform to preconceived ideas, but it is otherwise insufficientlycredible or comprehensiveto constitutea lasting addition to knowledge.--StORRSL. OLSON, Division of Birds, MRC 116, NationalMuseum of NaturalHistory, Smith- sonianInstitution, Washington, D.C. 20560, USA. TheAuk 117(3):839-840, 2000

LITERATURE CITED Avian Growth and Development: Evolution BURKE,A. C., AND A. FEOUCC•A.1997. Developmen- within the Altricial-Precocial Spectrum.-- Edited tal patternsand the identificationof homologies by J.Matthias Starck and R. E. Ricklefs.1998. Oxford in the avian hand. Science 278:666-668. University Press,Oxford. v + 441 pp., 177 figures. CLARK, J. M, M. A. NORELL, AND L. g. CHIAPPE. ISBN 0-19-510608-3. Cloth, $70.00.--This book is the 1999.An oviraptoridskeleton from theLate Cre- latestin the long and rich historyof seminalarticles, taceousof Ukhaa Tolgod,Mongolia, preserved symposia,and authoritative reviews on the subjectof in an avianlike brooding position over an ovi- avian eggs and growth and developmentof avian raptorid nest. American Museum Novitates embryos.The pioneeringwork of Portmunn,Nice, 3265:1-36. Hamburger,Romanoff, and othermore recenttreat- FEDUCCIA,g. 1999.The origin and evolution of birds, ments (Carey 1980, Seymour 1984, Metcalfe et al. 2nd. ed. Yale University Press,New Haven, Con- 1987,Deeming and Ferguson 1991) published on this necticut. subjectmay serveas a useful backgroundfor under- HINCHLIFFE,J. g. 1985. "One, two, three" or "two, standing the foundation on which this book was three,four": An embryologist'sview of the ho- written. Readingthese other booksfirst may be a mologiesof the digits and carpusof modern necessaryprerequisite for beginning graduate stu- birds. Pages141-147 in The beginningsof birds dents or ornithologists/developmentalbiologists