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The Condor 107:342–352q The Cooper Ornithological Society 2005

A NEW CYPSELOMORPH BIRD FROM THE MIDDLE EOCENEOF GERMANY AND THE EARLY DIVERSIFICATION OF AVIAN

AERIAL INSECTIVORES

GERALD MAYR1

Forschungsinstitut Senckenberg, Sektion fur Ornithologie, Senckenberganlage 25,D-60325 Frankfurt am Main, Germany

Abstract. A new taxon of the Cypselomorphae—the clade including nightjars, potoos,owlet-nightjars, and apodiform birds—is described from the middle Eocene of Messel inGermany. Phylogenetic analysis of 49 characters shows Protocypselomorphus manfredkel-leri gen. et sp. nov. to be the sister group of all other cypselomorph taxa, although thisplacement was not robust to bootstrapping. As evidenced by its swift-like beak, long fore-arm, and reduced feet, P. manfredkelleri was hawking insects on the wing. Thus it adds adistinctive new taxon to the already diverse assemblage of Paleogene aerial insectivores, allof which belong to the Cypselomorphae. This strongly contrasts with the extant avifaunawhere many aerial insectivores belong to songbirds, and among the insectivorous cypselo-morph taxa only swifts and nightjars are species rich and widely distributed. The diversityof aerial insectivores among the Cypselomorphae may have been reduced by food compe-tition with songbirds, which do not become the dominant group of insectivorous birds beforethe early Miocene.

Key words: Cypselomorphae, fossil birds, Paleogene avifauna, phylogeny, Protocypsel-omorphus manfredkelleri gen. et sp. nov.

Una Nueva Ave Cipselomorfa del Eoceno Medio de Alemania y la Diversificacion Tempranade las Aves Insectıvoras Aereas

Resumen. Se describe un nuevo taxon de Cypselomorphae, el clado que incluye a lasfamilias Caprimulgidae, Nyctibiidae, Aegothelidae y a las aves apodiformes, del Eocenomedio de Messel en Alemania. Un analisis filogenetico de 49 caracteres muestra que Pro-tocypselomorphus manfredkelleri gen. et sp. nov. es el grupo hermano de los demas taxade cipselomorfos, aunque esta posicion no fue apoyada por el analisis de bootstrap. Comolo evidencia su pico tipo vencejo, antebrazo largo y patas pequenas, P. manfredkelleri cazabainsectos al vuelo. Ası, este hallazgo anade un nuevo taxon al grupo ya diverso de losinsectıvoros aereos del Paleogeno, todos los cuales pertenecen al grupo de los cipselomorfos.Esto contrasta fuertemente con la avifauna actual, en que muchos insectıvoros aereos per-tenecen al grupo de los paseriformes, mientras que de los taxa de insectıvoros cipselomorfossolo los apodiformes y caprimulgidos presentan alta diversidad especıfica y se encuentranampliamente distribuidos. La diversidad de los insectıvoros aereos en los cipselomorfos pudehaberse reducido debido a la competencia por alimento con las aves paseriformes, las cualesno se transforman en el grupo dominante de aves insectıvoras sino hasta el Mioceno tem-prano.

INTRODUCTION

It has recently been shown that the traditional(Wetmore 1960) ‘‘Caprimulgiformes’’ (nightjarsand allies) are not monophyletic and that owletnightjars (Aegothelidae) are more closely relatedto apodiform birds (tree swifts [Hemiprocnidae],true swifts [Apodidae], and hummingbirds [Tro-chilidae]) than to other members of the ‘‘Capri-mulgiformes’’ (Mayr 2002, Mayr et al. 2003).

Manuscript received 16 March 2004; accepted 3 De-cember 2004.

1 E-mail: Gerald.Mayr@senckenberg.de

The clade including Aegothelidae and Apodifor-mes in turn is the sister taxon of nightjars (Ca-primulgidae) and potoos (Nyctibiidae, Mayr2002, Mayr et al. 2003). The monophyleticgroup including these taxa is here referred to asCypselomorphae (Mayr 2002, Mayr and Mane-gold 2002). Except for the nectarivorous hum-mingbirds, all cypselomorph birds are aerial in-sectivores.

The fossil record of the Cypselomorphae isquite good given the small size of these birds.All fossil cypselomorph birds described so farcan be assigned to either Caprimulgidae, Nycti-

NEW MIDDLE EOCENE AERIAL INSECTIVORE 343

biidae, or Apodiformes; all are within crowngroup Cypselomorphae. Caprimulgidae are onlyknown from a few bones from the Eocene ofFrance (Mourer-Chauvire 1988a) and NorthAmerica (Olson 1999), but both isolated bonesand complete skeletons of Nyctibiidae were de-scribed from the middle and late Eocene of Eu-rope (Mourer-Chauvire 1989, Mayr and Mane-gold 2002).

The early Eocene fossil record of apodiformbirds is especially extensive and a considerablediversity of different taxa has been described(reviewed in Mayr 2003a). There are stem grouprepresentatives of Apodidae and Trochilidae, butalso apodiform taxa that are outside crowngroup Apodiformes (Mayr 2003b), most notablythe Eocene/Oligocene Aegialornithidae (Collins1976, Mourer-Chauvire 1988b) and the late Pa-leocene/early Eocene Eocypselidae (Harrison1984, Kristoffersen 1997, 2002, Dyke et al.2004).

Here I describe a new cypselomorph birdfrom the middle Eocene of Messel in Germanythat exhibits a hitherto unknown bauplan, com-bining a nightjar-like humerus with an elongatedmanus and abbreviated feet. The new taxon ap-pears to be a basal member of the Cypselo-morphae, possibly being outside the crowngroup.

METHODS

If not indicated otherwise, osteological termi-nology follows Baumel and Witmer (1993). Di-mensions represent maximum length of the bonealong its longitudinal axis. The fossil specimenis deposited in Forschungsinstitut Senckenberg,Frankfurt am Main, Germany (SMF).

Osteological comparisons with extant taxa arebased on the following modern taxa in the or-nithological collection of SMF: Tinamidae:Crypturellus; Galliformes: Alectura, Lophura;Trogonidae: Harpactes, Pharomachrus, Trogon;Coraciidae: Coracias; Steatornithidae: Steator-nis; Podargidae: Podargus, Batrachostomus; Ca-primulgidae: Caprimulgus, Chordeiles, Hydrop-salis, Lurocalis, Nyctidromus, Phalaenoptilus;Nyctibiidae: Nyctibius; Aegothelidae: Aegothe-les; Hemiprocnidae: Hemiprocne; Cypseloidinae(Apodidae): Cypseloides, Streptoprocne; Apo-dinae (Apodidae): Apus, Chaetura; Trochilidae:Amazilia, Chrysolampis, Colibri, Glaucis, Phae-tornis.

The fossil Eocypselidae were coded after thetype specimen of Eocypselus vincenti Harrison1984 and figures of new specimens in Kristof-fersen (2002) and Dyke et al. (2004).

A phylogenetic analysis was performed withthe phylogenetic software PAUP (Version 3.1,Swofford 1993). The 49 morphological charac-ters included in this analysis (see appendices forcharacter descriptions and matrix) are largelybased on the revised character matrices of Mayr(2002, 2003b), with some new characters added.Two multistate characters were coded as ordered(25 and 40 in Appendix B). The shortest treeswere found with the branch-and-bound searchoption. Consistency index (CI) and rescaled con-sistency index (RC) were calculated, and the ro-bustness of the trees was evaluated with a boot-strap analysis of 1000 replicates.

Outgroup comparisons were made with thepalaeognathous Tinamidae and the Galliformes,which were shown to be among the most basalneornithine birds in recent phylogenetic analyses(Groth and Barrowclough 1999, Mayr andClarke 2003).

RESULTS

SYSTEMATIC PALEONTOLOGY

Cypselomorphae (sensu Mayr 2002)Protocypselomorphus gen. nov.

Differential diagnosis. Protocypselomorphusgen. nov. is a small anisodactyl bird, which isdiagnosed by the combination of the followingderived characters: (1) beak short and wide,swift-like; (2) sternum elongate with stronglycranially protruding carina sterni; (3) scapi cla-vicularum of furcula becoming markedly widertowards extremitas omalis; (4) phalanges of ma-jor digit strongly elongated, proximal and distalphalanx together exceeding carpometacarpus inlength; (5) tarsometatarsus very short, measur-ing only one third of length of ulna; (6) halluxlong.

Protocypselomorphus gen. nov. is distin-guished from apodiform birds by the plesio-morphic presence of a long and slender humerusand ulna. It differs from the superficially similarCaprimulgidae in the absence of greatly en-larged ossa palatina, a proportionally longer ma-nus and shorter tarsometatarsus, and a longerhallux.

Etymology. The genus name is derived fromproto (Greek): first, cypselus (Latin): a swift,

344 GERALD MAYR

FIGURE 1. Protocypselomorphus manfredkelleri gen. et sp. nov., holotype, coated with ammonium chlorideto enhance contrast. Abbreviations: p1—phalanx proximalis digiti majoris, p2—phalanx distalis digiti majoris.Scale bar equals 10 mm.

and morphus (Greek): shape, and indicates thatthe new taxon is considered to be a basal mem-ber of the Cypselomorphae.

Protocypselomorphus manfredkelleri sp. nov.(Fig. 1–3)

Holotype. SMF-ME 11043, articulated skele-ton lacking the right wing and right foot (Fig.1).

Diagnosis. As for genus.Type locality. Messel near Darmstadt, Ger-

many (Schaal and Ziegler 1988).

Type horizon. Lower middle Eocene (49 Ma;Legendre and Leveque 1997).

Dimensions. Left humerus, ;24.5 mm; leftulna, ;33 mm; left carpometacarpus, 18.4 mm;right femur, 13.8 mm; tibiotarsus, 19.0 mm(left), 19.6 mm (right); left tarsometatarsus, 10.0mm. Pedal phalanges: I1, 6.1 mm; II1, 4.0 mm;II2, 4.2 mm; III1, 3.7 mm; III2, 4.5 mm.

Etymology. The species is named after Man-fred Keller who found and prepared the holo-type, and donated it to SMF.

NEW MIDDLE EOCENE AERIAL INSECTIVORE 345

FIGURE 2. Protocypselomorphus manfredkelleri gen. et sp. nov., skull, coated with ammonium chloride toenhance contrast. Abbreviations: cv—cervical vertebra, hyo—hyoid apparatus, man—ramus of mandible, pal—angulus caudolateralis of right palatinum, qu—left quadratum. Scale bar equals 10 mm.

Description and comparison. The skull is ex-posed from its ventral side (Fig. 2). The ratherpoorly preserved beak measures about one thirdof the total skull length and is of similar shapeto that of extant swifts. The ossa palatina are notgreatly enlarged as in modern Caprimulgidaeand Nyctibiidae, but the angulus caudolateralis

is rounded as in the latter two taxa and not point-ed as in apodiform birds (Fig. 2). The left qua-dratum is situated between the ossa ceratobran-chialia of the hyoid bone and is visible from itscaudal side; capitulum squamosum and capitu-lum oticum are separated by a marked incisuraintercapitularis. As in other Cypselomorphae,

346 GERALD MAYR

the condylus medialis is poorly developed. Themandible is laterally displaced and lacks its dis-tal part. The rami mandibulae are of equal widthin their caudal half and not greatly widened anddorso-ventrally flattened as in Caprimulgidaeand Nyctibiidae. Contrary to Caprimulgidae andNyctibiidae, the mandible further lacks an intra-mandibular joint (see Buhler 1970) and its prox-imal articulation end is of average size (small inCaprimulgidae and Nyctibiidae).

The well preserved hyobranchial apparatus(Fig. 2) closely resembles that of extant swifts,e.g., Cypseloides (Apodidae). Also preserved isthe ossified cartilago cricoidea.

There are 19 or 20 free presacral vertebrae (itcannot be clearly discerned in the specimenwhether the most caudal vertebra is fused to thesynsacrum). Most extant ‘‘higher land birds’’(this term is used here to facilitate comparisons,but does not refer to a monophyletic taxon, seeMayr et al. 2003) have 19 free presacral verte-brae, but in the Apodidae and Hemiprocnidaethis number is 18 and there are only 17 presacralvertebrae in Caprimulgidae, Nyctibiidae, andTrochilidae. The thoracic vertebrae bear deeplateral excavations. The pygostyle is small.

Part of the extremitas sternalis of the coracoidis preserved (Fig. 3) and exhibits a short pro-cessus lateralis which is, however, not as greatlyreduced as in crown group Apodiformes. Owingto the fragmentary preservation of the coracoid,it cannot be discerned whether a foramen nervisupracoracoidei—within Cypselomorphae a dis-tinctive character of Aegothelidae and apodi-form birds—is present. Only fragments of theextremitas omalis are preserved, including asmall processus procoracoideus, similar to thatof modern Caprimulgidae (Fig. 3).

The proximal end of the scapula is visible inthe specimen (Fig. 3) and the acromion is ofsimilar length to that of the Hemiprocnidae.

The scapi clavicularum of the furcula greatlywiden towards the extremitas omalis, which isproportionally wider than in modern Cypselo-morphae (Fig. 3). There is an elongated proces-sus acromialis and a slightly elevated facies arti-cularis acrocoracoidea as in modern Caprimul-gidae (in crown group Apodiformes this facet ismore protruding).

The carina sterni is high with a strongly cra-nially protruding apex carinae (Fig. 3), the pilacarinae is distinct. The margo costalis of thesternum is long as in extant Apodiformes (short-

er in Aegothelidae and Caprimulgidae), five pro-cessus costales can be counted. The processuscraniolaterales are short and of similar shape tothose of extant swifts. There appear to be twoincisions in the caudal margin, although thesemay perhaps be an artifact.

In its shape and proportions, the humerus(Fig. 4) is similar to the corresponding bone ofextant Caprimulgidae and that of early EoceneNorth American fossils that were tentatively as-signed to the Caprimulgidae by Olson (1999). Itis much less abbreviated and stout than the hu-merus of crown group Apodiformes (Fig. 4).Whereas Protocypselomorphus manfredkellerihas the same overall size as the extant CommonSwift (Apus apus), its humerus is about twotimes longer. The crista deltopectoralis is situ-ated more proximally than in Caprimulgidae andextant Apodiformes. The distal end of the hu-merus is not well preserved but as far as com-parable, resembles the distal humerus of the Ca-primulgidae. The tuberculum supracondylareventrale is not greatly elongated as in modernswifts (Fig. 4). The processus flexorius is short.

The ulna is of similar proportions to the ulnaof Caprimulgidae, Aegothelidae, and many other‘‘higher land birds’’. It is proportionally muchlonger and less stout than the correspondingbone of crown group Apodiformes. The distalend of the bone resembles the distal ulna of theCaprimulgidae. Details of the proximal end can-not be discerned in the specimen. The radius ismarkedly sigmoidally curved as in extant Cap-rimulgidae, whereas it is less curved in the Ae-gothelidae, and straight in crown group Apodi-formes.

The manus (carpometacarpus and phalangesof the major digit) is very long, exceeding thehumerus in length (Fig. 4). The carpometacarpushas similar proportions to that of modern Apo-didae. On the proximal end, caudal to the pro-cessus pisiformis, there is a marked attachmentsite for the ligamentum radiocarpometacarpaleventrale. The processus extensorius is of similarshape to that of the Caprimulgidae, whereas itis more protruding in modern swifts.

The two phalanges of the major digit are verypoorly preserved and although their length andapproximate proportions can be discerned, mor-phological details are hardly visible; both pha-langes are proportionally more elongated than inthe Aegothelidae and Caprimulgidae, but not asstrongly as in crown group Apodiformes (Fig.

NEW MIDDLE EOCENE AERIAL INSECTIVORE 347

FIGURE 3. Protocypselomorphus manfredkelleri gen. et sp. nov., pectoral region, coated with ammoniumchloride to enhance contrast. Abbreviations: acr—acromion of scapula, apc—apex carinae (sternum), cor—coracoid, fu—furcula, hu—humerus, mco—margo costalis (sternum), pcl—processus craniolateralis (sternum),ppr—processus procoracoideus (coracoid), tv—thoracic vertebra. Scale bar equals 10 mm.

4). The phalanx digiti minoris is, however, notstrongly elongated as in Caprimulgidae andcrown group Apodiformes.

Details of pelvis and femur are not visible.The legs are short as in modern Apodiformes.There is no crest along the medial side of theproximal end of the tibiotarsus, opposite thecrista fibularis. The distal end of the tibiotarsusappears to have been of similar shape to that ofthe Aegialornithidae (Mourer-Chauvire 1988b:plate 1). The small condyli are separated by awide sulcus intercondylaris.

As in most Apodiformes, but contrary to thecorresponding bone of Caprimulgidae and Ae-gothelidae, the tarsometatarsus is strongly ab-breviated. The hypotarsus is large and protrud-ing and, in medial view, has a similar shape tothat of extant Aegothelidae. The proximal endof the articulation facet of the fairly long os me-tatarsale I is situated in the middle of the tar-sometatarsus. Details of the distal end of thebone cannot be discerned. Contrary to modernCaprimulgidae there is no ossified cartilago tib-ialis at the intertarsal joint.

348 GERALD MAYR

FIGURE 4. Comparison of left humerus and manus of cypselomorph birds. A, Protocypselomorphus man-fredkelleri gen. et sp. nov. B, Caprimulgus pectoralis (Caprimulgidae). C, Aegotheles cristatus (Aegothelidae).D, Hemiprocne comata (Hemiprocnidae). Abbreviations: cmc—carpometacarpus, dim—phalanx distalis digitimajoris, hum—humerus, min—phalanx digiti minoris, pi—processus internus indicis, prm—phalanx proximalisdigiti majoris, tsv—tuberculum supracondylare ventrale. Scale bars equal 5 mm.

FIGURE 5. Consensus tree of the 44 most parsimo-nious trees resulting from analysis of the character ma-trix in Appendix B (length 5 91, CI 5 0.59, RC 50.47). Bootstrap support values above 50% are indi-cated in parentheses next to the corresponding inter-nodes.

The phalanges of the second and third digitsare of average proportions, the fourth digit is notvisible in the specimen. As in crown group Apo-diformes but contrary to the Caprimulgidae, thehallux is very long. The claws are not preserved.

DISCUSSION

Protocypselomorphus manfredkelleri gen. et sp.nov. is referred to the Cypselomorphae becauseof the derived presence of (1) a very short, wide,swift-like beak, (2) quadrate with poorly devel-oped condylus medialis et caudalis, (3) extre-mitas omalis of furcula bearing an elevated fa-cies articularis acrocoracoidea, (4) manus elon-gated and distinctly exceeding carpometacarpusin length. There are no other fossil or extantnon-cypselomorph birds that exhibit this char-acter combination.

Analysis of the character matrix in AppendixB resulted in sister group relationship betweenthe new species and a clade including all othercypselomorph taxa (Fig. 5). However, this to-pology did not receive bootstrap support, prob-ably owing to the considerable amount of miss-ing data in the fossil taxa. P. manfredkelleri es-pecially differs from other taxa of the Cypselo-morphae in the primitive presence of 19 or 20presacral vertebrae (17 or 18 in other Cypselo-morphae). Concerning the other ingroup taxa,the phylogeny in Figure 5 is in concordance withpreviously published phylogenies of fossil andmodern Cypselomorphae (Mayr 2002, 2003b).

The combination of a short, swift-like beakwith a long forearm and reduced feet stronglysuggests that Protocypselomorphus was hawk-ing insects on the wing, as do many extantcypselomorph birds. Thus, the present study

NEW MIDDLE EOCENE AERIAL INSECTIVORE 349

adds a distinctive new taxon to the considerablediversity of avian aerial insectivores in the earlyEocene of Europe. In Messel (Germany) Pro-tocypselomorphus coexisted with stem groupApodidae (Scaniacypselus), stem group Nycti-biidae (Paraprefica), and a taxon of aerial in-sectivores possibly related to the extinct Ar-chaeotrogonidae (Hassiavis). In addition, stemgroup Trochilidae from Messel (Parargornis)still had a swift-like beak and may also havebeen catching insects by sallying flights (Mayr2003a, 2003b, Mayr and Manegold 2002). Anequally high diversity of aerial insectivores wasalso recorded from the early Eocene LondonClay deposits in England, including the apodi-form Eocypselidae (Eocypselus) and Aegialor-nithidae (Primapus), as well as hitherto undes-cribed archaeotrogons and nightjar-like taxa(Harrison 1984, Daniels in Feduccia 1999: table4.1).

With the possible exception of the Archaeo-trogonidae, the phylogenetic position of whichis uncertain, all Eocene aerial insectivores de-scribed from Europe so far are members of theCypselomorphae: in the Upper Eocene fissurefillings of the Quercy (France) the cypselomorphAegialornithidae are among the most abundantsmall birds.

By contrast, there are only two taxa of cypsel-omorph birds in Europe today: nightjars and trueswifts. Both have a worldwide distribution anddiversified into many species. All other insectiv-orous taxa of modern Cypselomorphae includefew species and have a restricted distribution:potoos only occur in the Neotropic region, tree-swifts in South-east Asia, and owlet-nightjars inthe Australian region.

Today most other avian insectivores that catchtheir prey either on the wing or by sallyingflights from perches belong to songbirds (Pas-seriformes), including swallows (Hirundinidae),flycatchers (Muscicapidae), drongos (Dicruri-dae), or shrikes (Laniidae) (e.g., Harrison 1978).In Europe, songbirds first occur towards the ear-ly Oligocene (30–34 Ma; Roux 2002, Mayr andManegold 2004), but still appear to have beenquite rare by that time before becoming thedominant group of small land birds towards theearly Miocene (Olson 1985).

As a working hypothesis, I consider it possi-ble that food competition with songbirds playeda major role in the extinction of many Paleogenecypselomorph insectivores—an assumption that

needs to be critically evaluated if more data onthe temporal distribution of these birds becomesavailable. Food competition between modernswifts and swallows is often avoided by the useof different nesting sites (Turner 1989). All otherextant insectivorous Cypselomorphae are cre-puscular or nocturnal and thereby contrast withthe mainly diurnal songbirds (whether therewere nocturnal taxa among Paleogene Cypselo-morphae is unknown).

ACKNOWLEDGMENTS

I thank Manfred Keller for donating the fossil speci-men to Forschungsinstitut Senckenberg and S. Trank-ner for taking the photographs. I further thank twoanonymous referees for comments on the manuscript.

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APPENDIX A.Character descriptions. Terminology follows Baumeland Witmer (1993) unless otherwise noted.

1. Skull, processus basipterygoidei: present (0), ab-sent (1) (Mayr 2002: character 1).

2. Ossa palatina with strongly protruding anguluscaudolateralis: no (0), yes (1) (Mayr 2002: char-acter 2).

3. Ossa palatina greatly enlarged: no (0), yes (1)(Mayr 2002: character 3).

4. Os palatinum and os pterygoideum fused: yes (0),no (1). Separated palatines and pterygoids are asynapomorphy of neognathous birds.

5. Cone-like osseous protrusion at caudal margin offoramen nervi optici: absent (0), present (1) (Mayr2002: character 5).

6. Beak very wide, with elongate narial openingsreaching almost to the tip of the beak: no (0), yes(1) (Mayr 2002: character 6).

7. Processus paroccipitales widely separated andstrongly ventrally protruding: no (0), yes (1)(Mayr 2002: character 7).

8. Processus orbitalis of quadratum greatly reduced:no (0), yes (1) (Mayr 2002: character 8).

9. Caudal surface of processus oticus of quadratumwith pneumatic foramina: no (0), yes (1) (Mayr2002: character 10).

10. Proximal end of mandible unusually small, withvery short cotyla lateralis and stout processus me-dialis: no (0), yes (1) (Mayr 2002: character 12).

11. Mandible with intraramal joint and caudal half oframi mandibulae greatly widened and dorso-ven-trally flattened: no (0), yes (1) (Mayr 2002: char-acter 13).

12. Number of presacral vertebrae: 19 or more (0), 18(1), 17 (2). Nyctibiidae, Caprimulgidae, and Tro-

NEW MIDDLE EOCENE AERIAL INSECTIVORE 351

chilidae have only 17 presacral vertebrae (contraMayr et al. 2003).

13. Coracoid, extremitas omalis distinctly hooked: no(0), yes (1) (Mayr 2002: character 16). The con-dition in Trochilidae is obscured by the fact thatthe processus acrocoracoideus is connected withthe processus procoracoideus by an osseousbridge.

14. Coracoid, foramen nervi supracoracoidei: absent(0), present (1) (Mayr 2002: character 18).

15. Coracoid, processus lateralis: not greatly reduced(0), greatly reduced (1) (Mayr 2002: character 19).

16. Coracoid, facies articularis sternalis dorso-ventral-ly greatly widened, greatest dorso-ventral width atleast half of greatest medio-lateral width: no (0),yes (1) (Mayr 2003b: character 1).

17. Coracoid, processus acrocoracoideus long, dis-tance from center of facies articularis scapularis totip of processus acrocoracoideus measuring aboutone third of entire length of coracoid, and tip ofprocessus acrocoracoideus reaching much farthermedially than medial margin of shaft: no (0), yes(1) (Mayr 2003b: character 2).

18. Furcula, extremitas omalis with long and slenderprocessus acromialis and distinct, laterally pro-truding facies articularis acrocoracoidea: no (0),yes (1) (Mayr 2003b: character 3).

19. Sternum, bifurcated spina externa: absent (0),present (1) (Mayr 2003b: character 4).

20. Sternum, sulci/facies articulares coracoidei: con-cave (0), saddle-shaped or slightly convex (1)(Mayr 2003b: character 5).

21. Sternum, caudal margin without incisions/fenes-trae: no (0), yes (1) (Mayr 2002: character 14,modified).

22. Humerus, crista deltopectoralis proximo-distallynarrow, strongly protruding and tapering: no (0),yes (1) (Mayr 2003b: character 7; note that codingof Scaniacypselus differs from Mayr 2003b).

23. Humerus, processus musculi extensor metacarpiradialis (terminology after Zusi and Bentz 1982)strongly developed and protruding: no (0), yes (1)(Mayr 2003b: character 8; note that coding of Jun-gornis differs from Mayr 2003b and that characterdescription in the latter reference erroneously re-fers to the reverse coding).

24. Humerus, processus musculi extensor metacarpiradialis shifted proximally, situated in proximaltwo thirds of the bone: no (0), yes (1) (Mayr2003b: character 9; note that character descriptionin Mayr 2003b erroneously refers to the reversecoding).

25. Humerus, ratio length of bone: width of shaft inmidsection: not as follows (0), less than 10.0 (1),less than 7.0 (2), less than 5.0 (3). This characterindicates the relative squatness of the bone andwas coded as ordered (Mayr 2003b: character 10,modified).

26. Humerus, well marked fossa musculi brachialis:present (0), absent (1) (Mayr 2003b: character 11).

27. Humerus, intumescentia humeri strongly raisedwith abrupt and steeply sloping dorsal margin: no(0), yes (1) (Mayr 2003b: character 12).

28. Humerus, caput humeri bearing a distinct distalprotrusion: no (0), yes (1) (Mayr 2003b: character13)

29. Humerus, tuberculum musculi pronator superficia-lis (terminology after Karhu 1988) strongly ven-trally protruding: no (0), yes (1) (Mayr 2003b:character 14)

30. Humerus, dorsal margin of distal end with sharpcrest distal to processus musculi extensor meta-carpi radialis: no (0), yes (1) (Mayr 2003b: char-acter 15).

31. Humerus, tuberculum supracondylare ventraleelongated and narrow: no (0), yes (1) (Mayr2003b: character 16).

32. Ulna, ratio maximum length of bone: width ofshaft in midsection less than 12: no (0), yes (1)(Mayr 2003b: character 17; note that this ratio haserroneously been listed in reversed order in Mayr2003b).

33. Ulna, olecranon: short and blunt (0), elongatedand narrow (1) (Mayr 2003b: character 18).

34. Ulna, cotyla ventralis with weakly pronouncedventro-proximal edge: no (0), yes (1) (Mayr2003b: character 19).

35. Radius, distal end with marked tubercle on ventralside of shaft, opposite to tuberculum carpale ofulna: no (0), yes (1) (Mayr 2003b: character 20).

36. Os carpi ulnare with crus longum being much lon-ger than crus breve: no (0), yes (1). Note that cod-ing of this character for Podargidae departs fromMayr et al. (2003).

37. Phalanges of major digit together exceeding car-pometacarpus in length: no (0), yes (1).

38. Phalanx proximalis digiti majoris with two markeddepressions that are separated by an oblique bulge:no (0), yes (1) (Mayr 2002: character 21).

39. Phalanx proximalis digiti majoris, processus inter-nus indicis (Fig. 4, terminology after Stegmann1963): absent or small (0), strongly developed (1)(Mayr 2002: character 22, modified).

40. Ratio length of manus (carpometacarpus 1 majordigit): length of humerus: less than 1.0 (0), 1.0–1.5 (1), 1.5–2.0 (2), more than 2.0 (3). This char-acter was coded as ordered.

41. Tibiotarsus, ridge on medial side of proximal end,opposite crista fibularis: absent (0), present (1).

42. Tarsometatarsus, hypotarsus, tendon of musculusflexor hallucis longus enclosed in bony canal: no(0), yes (1). Homology of tendinal furrows/canalswas deduced from position of bony canals.

43. Tarsometatarsus, ossified arcus extensorius: absent(0), present (1).

44. Tarsometatarsus, deep sulcus on dorsal surface,proximal to foramen vasculare distale: absent (0),present (1) (Mayr 2003b: character 25).

45. Trochlea metatarsi IV with elongated ridge alonglateral margin of plantar surface: no (0), yes (1).

46. Salivary glands greatly enlarged, owing to the factthat saliva is used in nest construction: no (0), yes(1) (Mayr 2003b: character 26, modified afterHolmgren 1998).

47. Musculus ambiens: present (0), absent (1); (afterMcKitrick 1991: character 29).

48. Musculus splenius capitis with cruciform origin:no (0), yes (1) (Mayr 2002: character 25); afterBurton (1971).

49. Caeca: well developed or rudimentary (0), absent(1) (Mayr 2002: character 24); after Beddard(1898).

352 GERALD MAYR

APPENDIX B. Character matrix of 49 morphological characters for Protocypselomorphus gen. nov., otherfossils (indicated by a cross) and extant taxa of the Cypselomorphae, and selected representatives of the ‘‘higherland birds.’’ See Appendix 1 for character definitions. Unknown character states are indicated by a dash, poly-morphic characters (01) by ‘‘a’’.

Taxa

Characters and character states

1–10 11–20 21–30 31–40 41–49

Tinamidae 0000000010 0010100000 0000010000 0000000000 000000000Galliformes 0001000000 0010100000 0000000000 0000000000 000000000Trogonidae 0001000000 0a00000010 0000000000 0000010000 010000100Coraciidae 1001000000 0000000000 0000000000 0000000000 000000100Podargidae 1101000000 0100000000 0000000000 0000010100 010010100Steatornithidae 0001000000 0000000000 0000000000 0000010010 000000100†Protocypselomorphus -00--1---0 00--00-0-- -0-0000-00 00----1--2 0--------Nyctibiidae 0011111101 1200000100 0000000000 0000010110 010000100Caprimulgidae 0011111101 1200000000 a000000000 0000010111 000000100Aegothelidae 1101010110 0-11100010 0000000000 0000010101 000000111†Eocypselidae ---------- --11100--- 0000100000 0000--0102 ---0-----†Aegialornithidae ---------- --11100-10 -010100000 0000---11- -0000----†Argornis ---------- --111000-- -1002-0000 0011--0113 ---------†Jungornis ---------- --11110001 1101310111 00-1------ ---------Trochilidae 1001000110 02-1110101 1011310111 0111011-13 000000111Hemiprocnidae 1101010110 0111100101 1000200000 1100111112 001101111†Scaniacypselus -----1---- 0-111-1--- 1111301000 1100--1113 ---------Cypseloidinae 1101010110 0111111101 1111301000 1100111113 100010111Apodinae 11010101-0 0111111101 1111311000 1110111113 101111111