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Specimen of Archąeopteryx

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Specimen of Archąeopteryx A new genus and species for the largest specimen of Archąeopteryx ANDRZEJ ELZANOWSKI Elżanowski, A. 2001. A new genus and species for the largest specimen of Archaeo- pteryx, - Acta Paląeontologica Polonica 46,4,519_532. The Solnhofen (Sixth) specimen of Archaeopteryx is assigned to Wellnhoferia grandis gen. et sp. n. on the basis of qualitative, size-independent autapomorphies. Wellnhoferia differs fuom Archaeopteryx in a short tail with the estimated number of 16-17 caudals; a nearly symmetric pattern of pedal rays II-IV with metatarsals II and IV of equal length and digit [V substantially shorter than in Archaeopteryx; and the number of four (instead of five) phalanges of pedal digit IV, which most probably results from a phylogenetic re- duction rather than individual vańation. A combination of large size and details of the pelvic limb suggests a locomotor specialization different from that of Archaeopteryx. K e y w o r d s : Archae optery x, Wellnhoferla, birds, Aves, Jurassic, Solnhofen. Andrzej Elżanowski [email protected]], Institute of Zoology, University of Wrocław, ul. Sienkiewicza 2], PL-50-335 Wrocław, Poland. Introduction The vicissitudesof the taxonomic treatmentof the Archaeopterygidaehave led to the prevailingskepticism as to thepossibility of establishingspecies differences between the sevenstudied specimens: London (ltt), Berlin (}nd),Third('Maxberg', lost from a pri- vatecollection), Haarlem (4th),Eichstiitt (silt), Solnhofen (6ilt), and Munich (7ft). Sepa- ratespecies have been erected for the London, Berlin, andEichstźitt specimens (Stephan 1987), but none of them has been widely accepted and the name Archaeopteryx Iithographicahas been broadly applied to the lst through 6th specimens(Wellnhofer 1992).However, a new species,Archaeopteryx bavarica, has been erectedfor the Mu- nich (7th)specimen (Wellnhofer lgg3),which is tentativelyaccepted here as evidenceof species-leveldifferentiation within the genusArchae opt e ry x. Paradoxically, the Solnhofen (6th)specimeno which is the largest and, as it turns out,the most distinct amongthe major (fairly complete)archaeopterygid specimens, is the only one that has not yet been classified into a separatespecies. This specimen,of Acta Palaeontol.Pol. 46. 4. 519-532. 520 New taxon for the largest Archaeopteryx: ELZANOWSKI Table 1. Meństic and qualitative differencesbetween the archaeopterygidspecimens. Eichstiitt Munich Berlin Haarlem Third London Solnhofen uaudal vertebrae z2 ZI ff ? ? 23 16-17est. ,| ,| Pedal disit IV phalanses 5 5 5 5? 4 Manual digit III ,l partly movable movable movable ? ? ph.Ilph.2 fused art. ,| ,| S capulocoracoidarticulation loose loose tieht tisht loose unknown origin in terms of exact horizon and locality, was identified as another Archaeopteryxspecimen and assignedto Archaeopteryxlithographica (Wellnhofer 1988a,1988b,1992).Wellnhofer reportedclose similaritiesin the tooth structureand limb proportionsbetween the Solnhofen and London specimensbut also noted and il- lustratedtwo striking differences:an abeffantphalangeal formula of the pes,which has been interpretedas a pathology (see also Osffom 1992)and the absenceof fusion be- tweenthe scapulaand coracoid, which has beenleft uninterpreted.A conservativetax- onomic treatmentof the Solnhofen specimen is justified in part by the context of its discovery and in part by its poor preservation,which has been made even worse throughthe unprofessionalhandling by its former private owner. The postcranialpart of the Solnhofen specimenis nearly complete,but most of the skull is gone. The vertebralcolumn, girdles, and proximal limb segmentsare heavily damagedby crushing and breaking againstone another.In addition, most long bones (including the tibiae and manualunguals) are collapsed,which makesthe comparisons of their diametersto thoseof otherspecimens impossible. Not collapsed are only meta- carpal III (in part),manual digit I phalanx 1, digit II phalanx2, digttIII phalanx 3, pubis, the right fibula, metatarsalI, metatarsalII (proximal half), pedal digit I phalanx 1, and pedal digit III phalanx3. The Solnhofen specimen was initially misidentified as Compsognathusand kept in a private collection before being identified as anotherArchaeopteryx specimen (Wellnhofer1988a, 1988b). Apparently as a result of this particularhistoric context, Wellnhoferstressed the many detailedsimilarities to Archaeopteryx,especially to the London specimen,and downplayed a few differenceshe noted (four phalangesin the fourth toe and unfused scapula and coracoid). However, detailed comparisons demonstratethat the Solnhofen specimen shows pronounceddifferences from thęArchaeopteryx specimens in meristic and qualitative characters(Table 1) as well as proportions(Tablesf-6), and that thereis no reasonto tręatthese differences as casesof individual variation.Therefore, the Solńofen speci- men is heretransferred to a new species,which is classifiedinto a new genusbecause of evidencefor species-leveldifferences among the specimensthat remain in the genus Arc haeopt ery x (Wellnhofer 1993). Systematic paleontology Class Aves Linnaeus, 1758 Family ArchaeopterygidaeHuxley, 1872 Genus Wellnhoferi,a,gen. n. Type species: Wellnhoferia grandis sp. n. ACTA PALAEONTOLOGTCA POLONTCA (46) (4) 521 Fig. 1. Weltnhoferiagrandis gen. et sp.r., the holotype Solnhofen (6th)specimen. The arrow points to the shortenedand narrowedterminal caudal vertebrae(followed by a mistakenly paintedextension of the tail). Scale bar 10 cm. Derivation of the name: In honor of Dr. Peter Wellnhofer, Chief Curator Emeritus, Bayerische Staatssammlung fiir Pakiontologie und historische Geologie, Munich. Diagnosis. - As for the species. Wellnhoferiagrandis sp. n. Fig. 1. Archaeopteryx lithographica: Wellnhofer 1988a: figs. I, f . Ar c haeo p te ry x Iitho g r ap hi c a: W elhthofer I 9 8 8b : pls. 1-8. Archae op te ryx litho g rap hic a: W ellnhofer 1992: figs. 1, 2. Archae opteryx sp.tOstrom I99f: ftg. 2B. 522 New taxon for the largest Archaeopteryx: ELZANOWSKI TableZ. Minimum depth(dorsoventral diameter) to lengthratios (in%o)of manual(M) andpedal (P) phalan- ges measurablein the Solnhofen and other specimensof the Archaeopterygidae.The measurementsarę listed in AppendicesI and2. Specimen MVI MIV2 PV1 PIIV3 P rt+ Eichstiitt 5.84 6.9 rf .7 TL.4 14.3 Munich 5.75 6.1 18.3 13.1 Berlin 6.0 6.2 12.8 15.1 Haarlem 8.2 London 2r.1 20.0 Solnhofen 8.4 8.9 15.0 18.I 25.3 Holotype: Solnhofen (6ft) specimen (Wellnhofer 1988a, 1988b, 1992) housed at the Btirgermeister- Mtiller-Museum, Solnhofen (Bavaria, Germany). Ępe horizon: unknown (probably Upper Solnhofen Lithographic Limestone), Late Jurassic (proba- bly Malm zeta2b,lower Lower Tithońan). Type locality: unknown (in all probability Altmtihl Valley, Bavaria, Germany). Derivation of the name: Latin grandis large. Material. - Only the holotype specimen including the nearly complete postcranial skeletonand the incomplete skull. Diagnosis. - Large archaeopterygidspecies that differs from Archaeopteryx species in having manual digit I with the ungual of approximatelyone third the length of the basalphalanx; pedal digit IV short(less than 80Vo the length of digit III)and composed of only four phalangesincluding a long ungual(the longest of all phalanges)with the flexor tubercle widely separatedfrom the ungual base; and a short tail with the esti- matednumber of 16-17 caudals. Descripti See Wellnhofer(1988a,b, L992). Comparisons. - The differencesbetween Archaeopteryx andWellnhoferia are most evident in the autopodialsand tail, probably becausethese parts are betterpreserved than the skull, girdles, and proximal limb segments,which largely defy detailed comparionswith other specimens. The scapula and coracoid are clearly separatein the Solnhofen (the largest),Mu- nich, and Eichstźitt(the smallest) specimens,but firmly connectedin the Berlin and London (secondlargest) specimens. This variationis clearly independentof size and thus more likely to reflect taxonomythan ontogeny.The backwardslant of the pubis in the Solnhofenspecimen is estimatedas 128"(Wellnhofer 1988b, 199f), which is more than 110"approximated for the remaining specimensincluding the Third (Wellnhofer 1985,1993). In the manus,the relative depthsof the only two phalangesthat are measurablein this respectin the Solnhofen specimenand the only one in the Haarlem specimenare much higher than in the remaining archaeopterygidspecimens, which do not reveal a positive allometryof this dimension(Table 2). Manual digit III phalanges1 andf are immovably connectedin the Solnhofen specimenby what appearsto be a convoluted suture(Wellnhofer 1988b: fig. 5.4,1992:fig. 10B) and suggestsa partialfusion, which also occursin the oviraptorids,e.$., Ingenia (H. osmólska personalcommunication). ACTA PALAEONTOLOGTCA POLONTCA (46) (4) 523 Table 3. Inter-and intradigitalproportions of the manusin the Archaeopterygidae(digits in Roman, phalan- ges in Arabic numerals).In parenthesesare ratios based on at leastone approximatemeasurement. The mea- surementsare listed in Appendix 1. Alt digits Digit I Digit II Digit III Specimen I+II+III=IUUVo I +f =100Vo t +2 +3 = I00Vo I+2+3+4=I00Vo Eichstritt f7.3+43.5+f9.f 68.8+ 31.2 (f3,3+ 10.2+ 44.2 +23.3) Berlin 27.2+ 44.0+28.8 66.f + 33.8 (31.9+40.5+27.6)20.8+13.0+40.1+26.1 Third (34+39+f7)L Haarlem 70.6+ 29.4' Solnhofen 26.5+ 43.6+299 75.1+24.9 f9.7+42.f+28.1 19.0+14.7+42.2+24.1 1 The ungual is not measurable. 2 Heller (1959). 3 Ostrom(1972). Table 4. Metatarsalratios (inVo) in the Archaeopterygidae.The measurementsare listed in Appendix 2.
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