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A specimen of Eocuculus Chandler, 1999 (Aves, ? Cuculidae) from the early Oligocene of France
Geobios 39 (2006) 865–872 http://france.elsevier.com/direct/GEOBIO/
Original article
A specimen of Eocuculus Chandler, 1999 (Aves, ? Cuculidae) from the early Oligocene of France Un spécimen d’Eocuculus Chandler, 1999 (Aves, ? Cuculidae) de l’Oligocène inférieur de France Gerald Mayr Forschungsinstitut Senckenberg, Sektion Ornithologie, Senckenberganlage 25, 60325 Frankfurt am Main, Germany Received 5 September 2005; accepted 31 October 2005 Available online 06 October 2006
Abstract A postcranial skeleton of a small bird from the early Oligocene locality Pichovet in Southern France is described and identified as Eocuculus cf. cherpinae Chandler, 1999. It is the second fossil record of Eocuculus which was hitherto known from a postcranial skeleton from the late Eocene of North America only. Although Eocuculus shares some derived similarities with Cuculidae (cuckoos), it distinctly differs in a number of osteological features from crown group members of this taxon. If future, more complete skeletons prove its cuculiform affinities, Eocuculus is a stem lineage representative of this taxon and not within the crown group. Recognition of Eocuculus in the early Oligocene of France provides evidence for the presence of an extinct late Eocene/early Oligocene avian taxon with an intercontinental Northern Hemisphere distribution. © 2006 Elsevier Masson SAS. All rights reserved. Résumé Un squelette post-crânien d’un petit oiseau de l’Oligocène inférieur du gisement de Pichovet, dans le Sud de la France, est décrit et attribué à Eocuculus cf. cherpinae Chandler, 1999. C’est la deuxième mention du Eocuculus qui était connu jusqu’alors uniquement par un squelette postcrânien provenant de l’Éocène supérieur d’Amérique du Nord. Bien qu’Eocuculus partage quelques caractères dérivés avec les Cuculidae (coucous), il diffère distinctement des membres du groupe couronne (crown group) de ce taxon par certains caractères ostéologiques. Si on trouvait dans le futur des squelettes plus complets prouvant ses affinités avec les Cuculiformes, Eocuculus pourrait être considéré comme un représentant de la lignée souche (stem group) de ce taxon et non du groupe couronne (crown group). L’identification d’Eocuculus dans l’Oligocène inférieur de France témoigne de la présence d’un taxon avien d’âge Eocène supérieur/Oligocène inférieur qui avait une répartition intercontinentale dans l’Hémisphère nord. © 2006 Elsevier Masson SAS. All rights reserved. Keywords: Fossil birds; Oligocene; Cuculidae; Eocuculus Mots clés : Oiseaux fossiles ; Oligocène ; Cuculidae ; Eocuculus
1. Introduction Whereas there is meanwhile a good avian fossil record from early Eocene European fossil sites, comparatively little is still known on small early Oligocene birds as there are only few
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fossil localities which yielded a greater number of avian fossils (Mayr, 2005a). Most notable among these are the lacustrine (Lutz, 1984) “Calcaires lithographiques” of the Luberon in Southern France, where several well-preserved articulated bird skeletons were found. Although many of the bird fossils from these localities are in private collections and even a decade ago no avian taxa were described in detail, meanwhile a diverse avifauna is known to have been present in the Luberon paleoenvironment.
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The hitherto described taxa include crane precursors (Parvigruidae, Mayr, 2005b), charadriiform birds (Bessonat and Michaut, 1973; Mayr, 2000; Roux, 2002), ibises (Threskiornithidae, Roux, 2002), and trogons (Trogonidae, Mayr, 1999, 2001). Other specimens in private collections were identified as passerines (Passeriformes), pelicans, (Pelecaniformes), and cormorants (Phalacrocoracidae) (Roux, 2002). Here, I report on an incomplete postcranial skeleton of a new small bird from the “Calcaires lithographiques de Vachères” (Fig. 1). Although the specimen is incomplete, it exhibits an excellent bone preservation which allows the recognition of several taxonomically informative details. In size and morphology it closely matches a postcranial skeleton from the late Eocene (32–34 million years ago; Chandler, 1999) of the North American Florissant Formation (Fig. 2), which was described as Eocuculus cherpinae by Chandler (1999) who assigned it to Cuculidae (cuckoos). The new specimen from the French locality provides additional information on the poorly known osteology and phylogenetic affinities of Eocuculus, and for the first time a detailed description of its osteology is given. 2. Material and methods The fossil specimen is deposited in Forschungsinstitut Senckenberg, Frankfurt am Main, Germany (SMF).
Osteological terminology follows Baumel and Witmer (1993). Measurements represent the maximum length of the bone along its longitudinal axis in millimeters; the claws are measured from the tip to the processus extensorius. Apart from representatives of all other avian “families”, osteological comparisons were made with the following taxa of extant Cuculidae (all in SMF): Carpococcyx renauldi, Centropus phasianus, C. superciliosus, Ceuthmochares aereus, Chrysococcyx caprius, C. xanthorhynchus, Clamator glandarius, Clamator levaillantii, Coua caerulea, C. cristata, Crotophaga ani, C. major, Cuculus canorus, Geococcyx californianus, Guira guira. 3. Systematic paleontology AVES Linnaeus, 1758. ?CUCULIFORMES Wagler, 1830. ?CUCULIDAE Leach, 1820. 3.1. Eocuculus Chandler, 1999 Emended diagnosis (1) Sternum very wide with four deep incisions in caudal margin; (2) wide pelvis without tubercula praeacetabularia, and (3) with processus terminalis ischii blunt and broad; (4) tarsometatarsus with prominent tuberositas musculi tibialis cranialis at the medial margin of the bone and (5)
Fig. 1. Eocuculus cf. cherpinae Chandler, 1999, referred specimen SMF Av 425 from the early Oligocene of France with interpretative drawing. Abbreviations: lfe, left femur; ltb, left tibiotarsus; ltm, left tarsometatarsus; pel, pelvis; pyg, pygostyle; r, rib; rfe, right femur; rtb, right tibiotarsus; rtm, right tarsometatarsus; st, sternum; v, vertebra. Scale bar equals 10 mm.
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elongated medial foramen vasculare proximale situated just proximal thereof, also at medial margin of tarsometatarsus; (6) foramen vasculare very small; (7) trochlea metatarsi III short and wide and without marked trochlear furrow on dorsal surface; (8) trochlea metatarsi IV reaching as far distally as the trochlea metatarsi II and lacking a well-developed trochlea accessoria; (9) third toe much wider than second toe. Characters (4)–(7) and (9) are here considered autapomorphic for Eocuculus. Taxonomic remarks: The new specimen closely resembles the slightly earlier E. cherpinae in size and osteology. Both share a semizygodactyl foot and characters (1), (4)–(9) listed in the diagnosis above (the other characters are not visible in the holotype of E. cherpinae).
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sacrum, 23.4 [23.1]; femur, 25.1 (right); tibiotarsus 35.0 (left) [33.7], 35.7 (right) [32.5]; tarsometatarsus, ~17.7 (left) [17.0], 17.6 (right) [17.0]; pedal phalanges, I1, 4.4; I2, 3.5; II1, 5.4; II2, 5.1; II3, 4.1; III1, 5.5; III2, 5.6; III3, 5.9; III4, 5.1; IV1, 4.0; IV2, 4.0; IV3, 3.4; IV4, 4.2; IV5, 4.6. Description and comparison: Vertebrae: Osteological details of the poorly preserved thoracic vertebrae, most of which are hidden under the sternum, cannot be discerned. There are five free caudal vertebrae. As in many extant Cuculidae, the corpus of the pygostyle is perforated on its caudoventral end and there is no greatly enlarged discus pygostyli, which is a derived characteristic of, e.g. piciform birds (woodpeckers and allies). Ribs: Five sternal ribs are preserved, but it cannot be discerned how many of these reached the sternum. 3.2. Eocuculus cf. cherpinae Chandler, 1999 (Figs. 1,3-5) Sternum: The sternum (Fig. 3) is very wide, with a welldeveloped carina sterni (the carina is low in many extant terrestrial Cuculidae, e.g. Coua). As in extant Cuculidae, the Referred specimen: SMF Av 425, postcranial skeleton apex carinae is pointed and strongly cranially protruding; the without wings and pectoral girdle on a single slab of limestone, cranial margin of the carina sterni is markedly concave. There which also contains two specimens of the fish Dapalis appears to have been a short spina externa as in extant Cucumacrurus (Serranidae) (Fig. 1). lidae, although its exact shape cannot be discerned as the tip Locality and horizon: Pichovet, Vachères, Alpes de Haute is hidden beneath a thoracic vertebra. Likewise, the tip of the Provence, Southern France; Lower Oligocene, MP 24 (about processus craniolateralis is covered by the left tibiotarsus. 30 million years ago; Mourer-Chauviré, 1996; Legendre and There are two pairs of deep incisions in the caudal margin Lévêque, 1997), “Calcaires lithographiques de Vachères”. of the corpus sterni, the lateral incisions are deeper than the Measurements (in brackets those of the holotype of medial ones. The trabeculae laterales and mediales terminate E. cherpinae, after Chandler, 1999): Carina sterni, ~32; synin short transverse processes. The trabecula mediana is narrow. Within Cuculidae, a four-notched sternum occurs in, e.g. Ceuthmochares, Chrysococcyx, Geococcyx, Coua, and Clamator, whereas other extant Cuculidae only exhibit two notches in the caudal margin of their sternum (e.g. Guira, Cuculus, Carpococcyx, Crotophaga; see also Berger, 1960: tab. 3). Pelvis: The well preserved pelvis (Fig. 4) is seen in ventral view and agrees with the pelvis of extant Cuculidae in that the processus terminalis ischii is blunt and broad (Fig. 4), whereas it tapers to a pointed tip in most other small “land birds” (except, e.g. Musophagidae [turacos] and Pteroclidae [sandgrouse]). In other features, however, the pelvis of Eocuculus is markedly different from that of extant Cuculidae. In its proportions it is more similar to the wide pelvis of trogons (Trogonidae) and taxa of the Cypselomorphae (nightjars, swifts, hummingbirds, and allies). As in the latter, the alae praeacetabulares ilii are short and their lateral margin is straight, not concave as in extant Cuculidae (Fig. 4). Also in contrast to extant Cuculidae, the cranio-lateral edges of the alae praeacetabulares ilii are not pointed and protruding. There are further no tubercula praeacetabularia, which are very marked in most extant Cuculidae (only weakly developed in Cuculus and Chrysococcyx). There is also no caudally closed foramen obturatum. In the midsection of the pelvis a marked processus costalis runs perpendicular to the longitudinal axis of the synFig. 2. Plastotype (cast of natural mould of holotype) of Eocuculus cherpinae, sacrum, whereas the transverse processes of the caudal synsaspecimen DM 10682 in dorsal view, deposited in the Denver Museum of Natural cral vertebrae meet the synsacrum at an angle of about 45°. History, Colorado, USA (from Chandler, 1999: Fig. 2). Scale bar equals 10 mm. The ventral surface of the most cranial and most caudal synsa-
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Fig. 3. Eocuculus cf. cherpinae Chandler, 1999, sternum of referred specimen SMF Av 425 in comparison. 1. Sternum of specimen SMF Av 425 in lateral view. 2. Sternum of the extant Levaillant’s Cuckoo, Clamator levaillantii (Cuculidae) in lateral view. Abbreviations: apc, apexa carinae; pcl, processus craniolateralis. Scale bars equal 10 mm.
Fig. 4. Eocuculus cf. cherpinae Chandler, 1999, pelvis of referred specimen SMF Av 425 in comparison. 1. Pelvis of specimen SMF Av 425 in ventral view. 2. Pelvis of the extant Levaillant’s Cuckoo, Clamator levaillantii (Cuculidae) in ventral view. Abbreviations: api, cranio-lateral edge of ala praeacetabularis ilii; lfe, left femur; no, notch between ilium and ischium; pti, processus terminalis ischii; pyg, pygostyle; rfe, right femur; tpa, tuberculum praeacetabulare. Scale bars equal 10 mm.
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cral vertebrae forms a ridge. There is no recessus caudalis fossae. Ilium and ischium are separated by a notch in the caudal margin of the pelvis (Fig. 4). The pubis exceeds the ischium in length. Femur: The femur is poorly preserved but, as in extant Cuculidae, appears to have had a wide distal end and a marked sulcus extensorius. On the distal end of the right femur a small patella is preserved. Tibiotarsus: The tibiotarsus is short and stout. The crista cnemialis cranialis protrudes slightly farther proximally than the crista cnemialis lateralis and the proximal end of the bone is thus asymmetric in cranial view. The condyli of the distal end are proximodistally low and widely spaced, the condylus medialis is slightly smaller than the condylus lateralis. The pons supratendineus is centrally positioned. The medial tuberositas retinaculi extensoris is situated much farther proximally than the lateral one. The fibula is long, reaching two thirds of the length of the tibiotarsus. Tarsometatarsus: The tarsometatarsus is short and stout, much more so than the corresponding bone of most extant cuckoos, of which the European Cuckoo, C. canorus, is among the taxa with the proportionally shortest tarsometatarsus (Fig. 5). Whereas the right tarsometatarsus exposes its dorsal surface, the left is seen in medio-plantar view. The shaft is of equal length over most of its length and only widens at the proximal and distal ends of the bone. As in E. cherpinae and some extant cuckoos (e.g. G. guira) it appears to have been slightly twisted so that the main planes of both ends are distorted against each other. The hypotarsus is small and bears a narrow furrow on the medial side of its plantar surface. As in extant Cuculidae (and various other avian taxa) there is no crista medianoplantaris. Also as in some extant Cuculidae (e.g. Guira, Cuculus, Chrysococcyx), the prominent tuberositas musculi tibialis cranialis is situated at the medial margin of the bone, the elongated medial foramen vasculare proximale just proximal thereof, also near the medial margin of the tarsometatarsus. In other extant Cuculidae (e.g. Geococcyx, Crotophaga, Clamator, Coua), however, the tuberositas musculi tibialis cranialis and the medial foramen vasculare proximale are more centrally positioned, which is the plesiomorphic condition found in most other birds. A lateral foramen vasculare proximale cannot be discerned in the specimen as the bone surface within the wide fossa infracotylaris dorsalis is badly crushed. Contrary to extant Cuculidae, the dorsal surface of the distal tarsometatarsus is convex and the trochleae metatarsorum II and IV are plantarly deflected. The foramen vasculare distale is small, whereas it is large in extant Cuculidae. The trochlea metatarsi II lacks a trochlear furrow and is larger than that of extant Cuculidae; its dorsal surface is rounded as in the latter. Contrary to extant Cuculidae the trochlea metatarsi III is short and wide and lacks a well-developed trochlear furrow on its dorsal surface. As in, e.g. C. canorus there is a shallow depression on the dorsal surface of the tarsometatarsus, just proximal to the trochlea of the third toe. On the dorsal surface of the distal end, between the trochleae metatarsorum III and IV, there is a narrow sulcus for the tendon of musculus extensor brevis digiti IV, which is also present but much wider
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in extant Cuculidae. The tarsometatarsus of Eocuculus most notably differs from that of extant Cuculidae in that the trochlea metatarsi IV lacks a well-developed trochlea accessoria (Sehnenhalter of Steinbacher, 1935; Fig. 5). The trochlea itself reaches as far distally as the trochlea metatarsi II, to the midsection of the trochlea metatarsi III, whereas the trochlea metatarsi IV is much shorter in extant Cuculidae, reaching only the basis of the trochlea metatarsi III. The tarsometatarsus of Eocuculus superficially resembles that of Eocene stem group parrots in its proportions (e.g. Mayr and Daniels, 1998: Fig. 18b), but is distinguished from psittaciform birds in the less developed trochlea accessoria and a smaller foramen vasculare distale. Toes: The toes exhibit the usual number of phalanges. The orientation of the fourth toe indicates that both feet are preserved in a semizygodactyl position, with the fourth toe spread laterally: Whereas the second and third toe of the left foot are seen in medial view, the fourth toe exposes its plantar surface; on the right foot, the second and third toe are visible from their dorsal side, but the fourth from its medial side (Fig. 5). Also in the holotype of E. cherpinae, the fourth toe appears to be preserved in a semizygodactyl position rather than being fully reversed (Figs. 2 and 5). The third toe is the longest and strongest toe and much wider than the second. The phalanges of the fourth toe are shorter than those of the second and third, the three proximal phalanges are slightly shorter than the fourth, but not greatly abbreviated as in the facultatively zygodactyl Coliiformes (mousebirds). The hallux is short, its proximal phalanx thin. The claws are weakly curved and bear only small tubercula flexoria. The os metatarsale I is small, with a short processus articularis tarsometatarsalis. 4. Discussion Cuckoos (Cuculidae) are an avian taxon with a worldwide distribution (Payne, 1997) and a virtually unknown evolutionary history. Some authors assume that “from their structure and distribution, the Cuculidae appear to be a relatively ancient family” (Olson, 1985: 110). However, only few Paleogene taxa were assigned to Cuculidae and most of these incorrectly. Neither the Paleocene Eutreptodactylus itaboraiensis Baird and Vickers-Rich, 1997 nor the early Eocene Parvicuculus minor Harrison and Walker, 1977 can be referred to this taxon (Mayr, 2005c; Mayr and Mourer-Chauviré, 2005; contra Harrison and Walker, 1977; Baird and Vickers-Rich, 1997). Likewise, assignment to the Cuculidae of Dynamopterus velox MilneEdwards, 1892, from an unknown locality of the Quercy fissure fillings in France, still has to be supported with derived characteristics, and the humerus of this species, the only known skeletal element, shows little resemblance to that of extant Cuculidae (pers. obs.). Neococcyx mccorquodalei Weigel, 1963 from the early Oligocene of North America appears to have been correctly identified as a Cuculidae but is based on a distal humerus only (Weigel, 1963). Among other features, cuckoos are characterized by obligate zygodactyly, i.e. the fourth toe is permanently retroverted. Sup-
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Fig. 5. Eocuculus cf. cherpinae Chandler, 1999, feet of referred specimen SMF Av 425 in comparison. 1. Right foot of specimen SMF Av 425 in dorsal view. 2. Right foot of plastotype of Eocuculus cherpinae Chandler, 1999 in dorsal view (specimen DM 10682). 3. Dorsal view of right tarsometatarsus of the extant Common Cuckoo, Cuculus canorus (Cuculidae). 4. Dorsal view of right tarsometatarsus of the extant Levaillant’s Cuckoo, Clamator levaillantii (Cuculidae). 5. Left foot of specimen SMF Av 425 in ventrolateral view. 6. Left foot of plastotype of Eocuculus cherpinae Chandler, 1999 in ventral view (specimen DM 10682). 7. Plantar view of left tarsometatarsus of the extant Common Cuckoo, Cuculus canorus (Cuculidae). 8. Plantar view of left tarsometatarsus of the extant Levaillant’s Cuckoo, Clamator levaillantii (Cuculidae). The toes are numbered. Abbreviations: fvd, foramen vasculare distale; fvp, medial foramen vasculare proximale; tac, trochlea accessoria; ttc, tuberositas musculi tibialis cranialis. Scale bars equal 10 mm.
posed presence of this character in E. cherpinae and a similar overall morphology to extant cuckoos appear to have been the reasons for Chandler (1999) to assign this species to Cuculidae, although no shared similarities were explicitly listed. Because of its short tarsometatarsus Chandler (1999) even assigned Eocuculus to a particular taxon within Cuculidae, the “arboreal cuckoos” (Cuculinae).
The new specimen from France shows that Eocuculus shares with extant Cuculidae a strongly cranially protruding apex carinae of the sternum and a markedly convex cranial margin of the carina sterni which are not found in any other extant small “land bird” taxon (Fig. 3). Also, the processus terminal ischii is wide and blunt as in extant Cuculidae and Musophagidae and not elongated and tapering as in most
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other small “land birds”. As exemplified by the more complete holotype of E. cherpinae (Fig. 2), the ulna of Eocuculus is further as long as the humerus, whereas it is longer than the humerus in most extant “higher land birds” (including parrots, Psittaciformes), and the furcula bears a well-developed apophysis furculae as in modern Cuculidae (Chandler, 1999: Fig. 3). However, of these similarities only the shape of the carina sterni is unquestionably derived within neornithine birds. The polarity of the shape of the processus terminal ischii is uncertain and a short ulna is a plesiomorphic feature that is also present in Mesozoic non-neornithine birds. Although Eocuculus more closely resembles cuckoos than any other extant avian taxon, it markedly differs from all crown group Cuculidae in several features. Most notably, the trochlea metatarsi IV bears no large trochlea accessoria which indicates that the foot of Eocuculus was semizygodactyl as that of extant Musophagidae rather than fully zygodactyl as in extant Cuculidae (contra Chandler, 1999). The pelvis further lacks even poorly developed tubercula praeacetabularia and the cranio-lateral edges of the alae praeacetabulares ilii are not pointed and protruding. Also, the dorsal surface of the distal end of the tarsometatarsus is convex, whereas it is essentially flat in crown group Cuculidae. The holotype of E. cherpinae further shows that the phalanx proximalis digiti majoris bears a well-developed processus internus indicis (Stegmann, 1963) which is invariably absent in extant Cuculidae. Apart from the latter feature and also with the possible exception of the lack of tubercula praeacetabularia (Mayr and Clarke, 2003), these characters are plesiomorphic for neornithine birds and show Eocuculus to be outside crown group Cuculidae. Thus, Eocuculus is at best a stem lineage member of Cuculidae and not within the crown group (contra Chandler, 1999). As detailed by Mayr (2005a) such a distinction is important because of the increasing use of fossil taxa for calibration of avian molecular clocks. Although Eocuculus provides a minimum date for the divergence of cuckoos from their sister taxon if future more complete skeletons prove its cuculiform affinities, it does not allow calibration of any divergences within crown group Cuculidae, which are unknown from Paleogene fossil localities. Judging from the proportions of its hind limb elements, Eocuculus probably was a non-terrestrial, possibly arboreal taxon as assumed by Chandler (1999). If it is a stem lineage representative of the Cuculidae, its morphology is thus at odds with the recently proposed hypothesis that the stem species of cuckoos was a terrestrial bird (Hughes, 2000; see also Aragón et al., 1999; Sorenson and Payne, 2002). Recognition of Eocuculus in the early Oligocene of France provides further evidence for the presence of an extinct late Eocene/early Oligocene “land bird” taxon with an intercontinental Northern Hemisphere distribution (another example can be found in Mourer-Chauviré, 1985). As is the case with all other fossil taxa yet described from the “Calcaires lithographiques” of the Luberon area, Eocuculus is unknown from the early Oligocene deposits of the geographically close and well-studied Quercy fissure fillings, which
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either indicates a different paleohabitat of these localities or taphonomic biases in the preservation of avian fossils. Acknowledgements I thank S. Tränkner for taking the photographs of the French specimen and R. Chandler for providing photographs of the holotype of E. cherpinae. I further thank C. Mourer-Chauviré and U. Göhlich for reviewing the manuscript. References Aragón, S., Møller, A.P., Soler, J.J., Soler, M., 1999. Molecular phylogeny of cuckoos supports a polyphyletic origin of brood parasitism. Journal of Evolutionary Biology 12, 495–506. Baird, R.F., Vickers-Rich, P., 1997. Eutreptodactylus itaboraiensis gen. and sp. nov., an early cuckoo (Aves: Cuculiformes) from the Late Paleocene of Brazil. Alcheringa 21, 123–127. Baumel, J.J., Witmer, L.M., 1993. Osteologia. In: Baumel, J.J., King, A.S., Breazile, J.E., Evans, H.E., Vanden Berge, J.C. (Eds.), Handbook of avian anatomy: Nomina anatomica avium. Publications of the Nuttall Ornithological Club 23, Cambridge. pp. 45–132. Berger, A.J., 1960. Some anatomical characters of the Cuculidae and the Musophagidae. Wilson Bulletin 72, 60–104. Bessonat, G., Michaut, A., 1973. Découverte d’un squelette complet d’échassier dans le Stampien provençal. Bulletin du Muséum d’Histoire Naturelle de Marseille 33, 143–145. Chandler, R.M., 1999. Fossil birds of Florissant, Colorado: with a description of a new genus and species of cuckoo. Geologic Resources Division Technical Report NPS/NRGRD/GRDTR-99, 49–53. Harrison, C.J.O., Walker, C.A., 1977. Birds of the British Lower Eocene. Tertiary Research Special Papers 3, 1–52. Hughes, J.M., 2000. Monophyly and phylogeny of cuckoos (Aves, Cuculidae) inferred from osteological characters. Zoological Journal of the Linnean Society 130, 263–307. Legendre, S., Lévêque, F., 1997. Étalonnage de l’échelle biochronologique mammalienne du Paléogène d’Europe occidentale : vers une intégration à l’échelle globale. In: Aguilar, J.-P., Legendre, S., Michaux, J. (Eds.), Actes du Congrès BiochroM’97. Mémoires et Travaux de l’École Pratique des Hautes Études, Institut de Montpellier 21. pp. 461–473. Lutz, H., 1984. Beitrag zur Kenntnis der Unteroligozänen Insektenfauna von Céreste (Süd-Frankreich). Documenta Naturae 21, 1–26. Mayr, G., 1999. A new trogon from the Middle Oligocene of Céreste, France. Auk 116, 427–434. Mayr, G., 2000. Charadriiform birds from the early Oligocene of Céreste (France) and the Middle Eocene of Messel (Hessen, Germany). Geobios 33, 625–636. Mayr, G., 2001. A second skeleton of the early Oligocene trogon Primotrogon wintersteini Mayr, 1999 (Aves: Trogoniformes: Trogonidae) in an unusual state of preservation. Senckenbergiana Lethaea 81, 335–338. Mayr, G., 2005a. The Paleogene fossil record of birds in Europe. Biological Reviews 80, 515–542. Mayr, G., 2005b. A chicken-sized crane precursor from the early Oligocene of France. Naturwissenschaften 92, 389–393. Mayr, G., 2005c. Phylogenetic affinities and composition of the early Eocene Gracilitarsidae (Aves? Piciformes). Neues Jahrbuch für Geologie und Paläontologie, Monatshefte 2005, 1–16. Mayr, G., Clarke, J., 2003. The deep divergences of neornithine birds: a phylogenetic analysis of morphological characters. Cladistics 19, 527–553. Mayr, G., Daniels, M., 1998. Eocene parrots from Messel (Hessen, Germany) and the London Clay of Walton-on-the-Naze (Essex, England). Senckenbergiana Lethaea 78, 157–177. Mayr, G., Mourer-Chauviré, C., 2005. A specimen of Parvicuculus Harrison and Walker, 1977 (Aves: Parvicuculidae) from the early Eocene of France. Bulletin of the British Ornithologists’ Club 125, 299–304.
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Roux, T., 2002. Deux fossiles d’oiseaux de l’Oligocène inférieur du Luberon. Courrier Scientifique du Parc Naturel Régional du Luberon 6, 38–57. Sorenson, M.D., Payne, R.B., 2002. Molecular genetic perspectives on avian brood parasitism. Integrative and Comparative Biology 42, 388–400. Stegmann, B., 1963. Der Processus internus indicis im Skelett des Vogelflügels. Journal für Ornithologie 104, 413–423. Steinbacher, G., 1935. Funktionell-anatomische Untersuchungen an Vogelfüßen mit Wendezehen und Rückzehen. Journal für Ornithologie 83, 214–282. Weigel, R.D., 1963. Oligocene birds from Saskatchewan. Quarterly Journal of the Florida Academy of Science 26, 257–262.
Original article
A specimen of Eocuculus Chandler, 1999 (Aves, ? Cuculidae) from the early Oligocene of France Un spécimen d’Eocuculus Chandler, 1999 (Aves, ? Cuculidae) de l’Oligocène inférieur de France Gerald Mayr Forschungsinstitut Senckenberg, Sektion Ornithologie, Senckenberganlage 25, 60325 Frankfurt am Main, Germany Received 5 September 2005; accepted 31 October 2005 Available online 06 October 2006
Abstract A postcranial skeleton of a small bird from the early Oligocene locality Pichovet in Southern France is described and identified as Eocuculus cf. cherpinae Chandler, 1999. It is the second fossil record of Eocuculus which was hitherto known from a postcranial skeleton from the late Eocene of North America only. Although Eocuculus shares some derived similarities with Cuculidae (cuckoos), it distinctly differs in a number of osteological features from crown group members of this taxon. If future, more complete skeletons prove its cuculiform affinities, Eocuculus is a stem lineage representative of this taxon and not within the crown group. Recognition of Eocuculus in the early Oligocene of France provides evidence for the presence of an extinct late Eocene/early Oligocene avian taxon with an intercontinental Northern Hemisphere distribution. © 2006 Elsevier Masson SAS. All rights reserved. Résumé Un squelette post-crânien d’un petit oiseau de l’Oligocène inférieur du gisement de Pichovet, dans le Sud de la France, est décrit et attribué à Eocuculus cf. cherpinae Chandler, 1999. C’est la deuxième mention du Eocuculus qui était connu jusqu’alors uniquement par un squelette postcrânien provenant de l’Éocène supérieur d’Amérique du Nord. Bien qu’Eocuculus partage quelques caractères dérivés avec les Cuculidae (coucous), il diffère distinctement des membres du groupe couronne (crown group) de ce taxon par certains caractères ostéologiques. Si on trouvait dans le futur des squelettes plus complets prouvant ses affinités avec les Cuculiformes, Eocuculus pourrait être considéré comme un représentant de la lignée souche (stem group) de ce taxon et non du groupe couronne (crown group). L’identification d’Eocuculus dans l’Oligocène inférieur de France témoigne de la présence d’un taxon avien d’âge Eocène supérieur/Oligocène inférieur qui avait une répartition intercontinentale dans l’Hémisphère nord. © 2006 Elsevier Masson SAS. All rights reserved. Keywords: Fossil birds; Oligocene; Cuculidae; Eocuculus Mots clés : Oiseaux fossiles ; Oligocène ; Cuculidae ; Eocuculus
1. Introduction Whereas there is meanwhile a good avian fossil record from early Eocene European fossil sites, comparatively little is still known on small early Oligocene birds as there are only few
E-mail address: [email protected] (G. Mayr). 0016-6995/$ - see front matter © 2006 Elsevier Masson SAS. All rights reserved. doi:10.1016/j.geobios.2005.10.007
fossil localities which yielded a greater number of avian fossils (Mayr, 2005a). Most notable among these are the lacustrine (Lutz, 1984) “Calcaires lithographiques” of the Luberon in Southern France, where several well-preserved articulated bird skeletons were found. Although many of the bird fossils from these localities are in private collections and even a decade ago no avian taxa were described in detail, meanwhile a diverse avifauna is known to have been present in the Luberon paleoenvironment.
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The hitherto described taxa include crane precursors (Parvigruidae, Mayr, 2005b), charadriiform birds (Bessonat and Michaut, 1973; Mayr, 2000; Roux, 2002), ibises (Threskiornithidae, Roux, 2002), and trogons (Trogonidae, Mayr, 1999, 2001). Other specimens in private collections were identified as passerines (Passeriformes), pelicans, (Pelecaniformes), and cormorants (Phalacrocoracidae) (Roux, 2002). Here, I report on an incomplete postcranial skeleton of a new small bird from the “Calcaires lithographiques de Vachères” (Fig. 1). Although the specimen is incomplete, it exhibits an excellent bone preservation which allows the recognition of several taxonomically informative details. In size and morphology it closely matches a postcranial skeleton from the late Eocene (32–34 million years ago; Chandler, 1999) of the North American Florissant Formation (Fig. 2), which was described as Eocuculus cherpinae by Chandler (1999) who assigned it to Cuculidae (cuckoos). The new specimen from the French locality provides additional information on the poorly known osteology and phylogenetic affinities of Eocuculus, and for the first time a detailed description of its osteology is given. 2. Material and methods The fossil specimen is deposited in Forschungsinstitut Senckenberg, Frankfurt am Main, Germany (SMF).
Osteological terminology follows Baumel and Witmer (1993). Measurements represent the maximum length of the bone along its longitudinal axis in millimeters; the claws are measured from the tip to the processus extensorius. Apart from representatives of all other avian “families”, osteological comparisons were made with the following taxa of extant Cuculidae (all in SMF): Carpococcyx renauldi, Centropus phasianus, C. superciliosus, Ceuthmochares aereus, Chrysococcyx caprius, C. xanthorhynchus, Clamator glandarius, Clamator levaillantii, Coua caerulea, C. cristata, Crotophaga ani, C. major, Cuculus canorus, Geococcyx californianus, Guira guira. 3. Systematic paleontology AVES Linnaeus, 1758. ?CUCULIFORMES Wagler, 1830. ?CUCULIDAE Leach, 1820. 3.1. Eocuculus Chandler, 1999 Emended diagnosis (1) Sternum very wide with four deep incisions in caudal margin; (2) wide pelvis without tubercula praeacetabularia, and (3) with processus terminalis ischii blunt and broad; (4) tarsometatarsus with prominent tuberositas musculi tibialis cranialis at the medial margin of the bone and (5)
Fig. 1. Eocuculus cf. cherpinae Chandler, 1999, referred specimen SMF Av 425 from the early Oligocene of France with interpretative drawing. Abbreviations: lfe, left femur; ltb, left tibiotarsus; ltm, left tarsometatarsus; pel, pelvis; pyg, pygostyle; r, rib; rfe, right femur; rtb, right tibiotarsus; rtm, right tarsometatarsus; st, sternum; v, vertebra. Scale bar equals 10 mm.
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elongated medial foramen vasculare proximale situated just proximal thereof, also at medial margin of tarsometatarsus; (6) foramen vasculare very small; (7) trochlea metatarsi III short and wide and without marked trochlear furrow on dorsal surface; (8) trochlea metatarsi IV reaching as far distally as the trochlea metatarsi II and lacking a well-developed trochlea accessoria; (9) third toe much wider than second toe. Characters (4)–(7) and (9) are here considered autapomorphic for Eocuculus. Taxonomic remarks: The new specimen closely resembles the slightly earlier E. cherpinae in size and osteology. Both share a semizygodactyl foot and characters (1), (4)–(9) listed in the diagnosis above (the other characters are not visible in the holotype of E. cherpinae).
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sacrum, 23.4 [23.1]; femur, 25.1 (right); tibiotarsus 35.0 (left) [33.7], 35.7 (right) [32.5]; tarsometatarsus, ~17.7 (left) [17.0], 17.6 (right) [17.0]; pedal phalanges, I1, 4.4; I2, 3.5; II1, 5.4; II2, 5.1; II3, 4.1; III1, 5.5; III2, 5.6; III3, 5.9; III4, 5.1; IV1, 4.0; IV2, 4.0; IV3, 3.4; IV4, 4.2; IV5, 4.6. Description and comparison: Vertebrae: Osteological details of the poorly preserved thoracic vertebrae, most of which are hidden under the sternum, cannot be discerned. There are five free caudal vertebrae. As in many extant Cuculidae, the corpus of the pygostyle is perforated on its caudoventral end and there is no greatly enlarged discus pygostyli, which is a derived characteristic of, e.g. piciform birds (woodpeckers and allies). Ribs: Five sternal ribs are preserved, but it cannot be discerned how many of these reached the sternum. 3.2. Eocuculus cf. cherpinae Chandler, 1999 (Figs. 1,3-5) Sternum: The sternum (Fig. 3) is very wide, with a welldeveloped carina sterni (the carina is low in many extant terrestrial Cuculidae, e.g. Coua). As in extant Cuculidae, the Referred specimen: SMF Av 425, postcranial skeleton apex carinae is pointed and strongly cranially protruding; the without wings and pectoral girdle on a single slab of limestone, cranial margin of the carina sterni is markedly concave. There which also contains two specimens of the fish Dapalis appears to have been a short spina externa as in extant Cucumacrurus (Serranidae) (Fig. 1). lidae, although its exact shape cannot be discerned as the tip Locality and horizon: Pichovet, Vachères, Alpes de Haute is hidden beneath a thoracic vertebra. Likewise, the tip of the Provence, Southern France; Lower Oligocene, MP 24 (about processus craniolateralis is covered by the left tibiotarsus. 30 million years ago; Mourer-Chauviré, 1996; Legendre and There are two pairs of deep incisions in the caudal margin Lévêque, 1997), “Calcaires lithographiques de Vachères”. of the corpus sterni, the lateral incisions are deeper than the Measurements (in brackets those of the holotype of medial ones. The trabeculae laterales and mediales terminate E. cherpinae, after Chandler, 1999): Carina sterni, ~32; synin short transverse processes. The trabecula mediana is narrow. Within Cuculidae, a four-notched sternum occurs in, e.g. Ceuthmochares, Chrysococcyx, Geococcyx, Coua, and Clamator, whereas other extant Cuculidae only exhibit two notches in the caudal margin of their sternum (e.g. Guira, Cuculus, Carpococcyx, Crotophaga; see also Berger, 1960: tab. 3). Pelvis: The well preserved pelvis (Fig. 4) is seen in ventral view and agrees with the pelvis of extant Cuculidae in that the processus terminalis ischii is blunt and broad (Fig. 4), whereas it tapers to a pointed tip in most other small “land birds” (except, e.g. Musophagidae [turacos] and Pteroclidae [sandgrouse]). In other features, however, the pelvis of Eocuculus is markedly different from that of extant Cuculidae. In its proportions it is more similar to the wide pelvis of trogons (Trogonidae) and taxa of the Cypselomorphae (nightjars, swifts, hummingbirds, and allies). As in the latter, the alae praeacetabulares ilii are short and their lateral margin is straight, not concave as in extant Cuculidae (Fig. 4). Also in contrast to extant Cuculidae, the cranio-lateral edges of the alae praeacetabulares ilii are not pointed and protruding. There are further no tubercula praeacetabularia, which are very marked in most extant Cuculidae (only weakly developed in Cuculus and Chrysococcyx). There is also no caudally closed foramen obturatum. In the midsection of the pelvis a marked processus costalis runs perpendicular to the longitudinal axis of the synFig. 2. Plastotype (cast of natural mould of holotype) of Eocuculus cherpinae, sacrum, whereas the transverse processes of the caudal synsaspecimen DM 10682 in dorsal view, deposited in the Denver Museum of Natural cral vertebrae meet the synsacrum at an angle of about 45°. History, Colorado, USA (from Chandler, 1999: Fig. 2). Scale bar equals 10 mm. The ventral surface of the most cranial and most caudal synsa-
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Fig. 3. Eocuculus cf. cherpinae Chandler, 1999, sternum of referred specimen SMF Av 425 in comparison. 1. Sternum of specimen SMF Av 425 in lateral view. 2. Sternum of the extant Levaillant’s Cuckoo, Clamator levaillantii (Cuculidae) in lateral view. Abbreviations: apc, apexa carinae; pcl, processus craniolateralis. Scale bars equal 10 mm.
Fig. 4. Eocuculus cf. cherpinae Chandler, 1999, pelvis of referred specimen SMF Av 425 in comparison. 1. Pelvis of specimen SMF Av 425 in ventral view. 2. Pelvis of the extant Levaillant’s Cuckoo, Clamator levaillantii (Cuculidae) in ventral view. Abbreviations: api, cranio-lateral edge of ala praeacetabularis ilii; lfe, left femur; no, notch between ilium and ischium; pti, processus terminalis ischii; pyg, pygostyle; rfe, right femur; tpa, tuberculum praeacetabulare. Scale bars equal 10 mm.
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cral vertebrae forms a ridge. There is no recessus caudalis fossae. Ilium and ischium are separated by a notch in the caudal margin of the pelvis (Fig. 4). The pubis exceeds the ischium in length. Femur: The femur is poorly preserved but, as in extant Cuculidae, appears to have had a wide distal end and a marked sulcus extensorius. On the distal end of the right femur a small patella is preserved. Tibiotarsus: The tibiotarsus is short and stout. The crista cnemialis cranialis protrudes slightly farther proximally than the crista cnemialis lateralis and the proximal end of the bone is thus asymmetric in cranial view. The condyli of the distal end are proximodistally low and widely spaced, the condylus medialis is slightly smaller than the condylus lateralis. The pons supratendineus is centrally positioned. The medial tuberositas retinaculi extensoris is situated much farther proximally than the lateral one. The fibula is long, reaching two thirds of the length of the tibiotarsus. Tarsometatarsus: The tarsometatarsus is short and stout, much more so than the corresponding bone of most extant cuckoos, of which the European Cuckoo, C. canorus, is among the taxa with the proportionally shortest tarsometatarsus (Fig. 5). Whereas the right tarsometatarsus exposes its dorsal surface, the left is seen in medio-plantar view. The shaft is of equal length over most of its length and only widens at the proximal and distal ends of the bone. As in E. cherpinae and some extant cuckoos (e.g. G. guira) it appears to have been slightly twisted so that the main planes of both ends are distorted against each other. The hypotarsus is small and bears a narrow furrow on the medial side of its plantar surface. As in extant Cuculidae (and various other avian taxa) there is no crista medianoplantaris. Also as in some extant Cuculidae (e.g. Guira, Cuculus, Chrysococcyx), the prominent tuberositas musculi tibialis cranialis is situated at the medial margin of the bone, the elongated medial foramen vasculare proximale just proximal thereof, also near the medial margin of the tarsometatarsus. In other extant Cuculidae (e.g. Geococcyx, Crotophaga, Clamator, Coua), however, the tuberositas musculi tibialis cranialis and the medial foramen vasculare proximale are more centrally positioned, which is the plesiomorphic condition found in most other birds. A lateral foramen vasculare proximale cannot be discerned in the specimen as the bone surface within the wide fossa infracotylaris dorsalis is badly crushed. Contrary to extant Cuculidae, the dorsal surface of the distal tarsometatarsus is convex and the trochleae metatarsorum II and IV are plantarly deflected. The foramen vasculare distale is small, whereas it is large in extant Cuculidae. The trochlea metatarsi II lacks a trochlear furrow and is larger than that of extant Cuculidae; its dorsal surface is rounded as in the latter. Contrary to extant Cuculidae the trochlea metatarsi III is short and wide and lacks a well-developed trochlear furrow on its dorsal surface. As in, e.g. C. canorus there is a shallow depression on the dorsal surface of the tarsometatarsus, just proximal to the trochlea of the third toe. On the dorsal surface of the distal end, between the trochleae metatarsorum III and IV, there is a narrow sulcus for the tendon of musculus extensor brevis digiti IV, which is also present but much wider
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in extant Cuculidae. The tarsometatarsus of Eocuculus most notably differs from that of extant Cuculidae in that the trochlea metatarsi IV lacks a well-developed trochlea accessoria (Sehnenhalter of Steinbacher, 1935; Fig. 5). The trochlea itself reaches as far distally as the trochlea metatarsi II, to the midsection of the trochlea metatarsi III, whereas the trochlea metatarsi IV is much shorter in extant Cuculidae, reaching only the basis of the trochlea metatarsi III. The tarsometatarsus of Eocuculus superficially resembles that of Eocene stem group parrots in its proportions (e.g. Mayr and Daniels, 1998: Fig. 18b), but is distinguished from psittaciform birds in the less developed trochlea accessoria and a smaller foramen vasculare distale. Toes: The toes exhibit the usual number of phalanges. The orientation of the fourth toe indicates that both feet are preserved in a semizygodactyl position, with the fourth toe spread laterally: Whereas the second and third toe of the left foot are seen in medial view, the fourth toe exposes its plantar surface; on the right foot, the second and third toe are visible from their dorsal side, but the fourth from its medial side (Fig. 5). Also in the holotype of E. cherpinae, the fourth toe appears to be preserved in a semizygodactyl position rather than being fully reversed (Figs. 2 and 5). The third toe is the longest and strongest toe and much wider than the second. The phalanges of the fourth toe are shorter than those of the second and third, the three proximal phalanges are slightly shorter than the fourth, but not greatly abbreviated as in the facultatively zygodactyl Coliiformes (mousebirds). The hallux is short, its proximal phalanx thin. The claws are weakly curved and bear only small tubercula flexoria. The os metatarsale I is small, with a short processus articularis tarsometatarsalis. 4. Discussion Cuckoos (Cuculidae) are an avian taxon with a worldwide distribution (Payne, 1997) and a virtually unknown evolutionary history. Some authors assume that “from their structure and distribution, the Cuculidae appear to be a relatively ancient family” (Olson, 1985: 110). However, only few Paleogene taxa were assigned to Cuculidae and most of these incorrectly. Neither the Paleocene Eutreptodactylus itaboraiensis Baird and Vickers-Rich, 1997 nor the early Eocene Parvicuculus minor Harrison and Walker, 1977 can be referred to this taxon (Mayr, 2005c; Mayr and Mourer-Chauviré, 2005; contra Harrison and Walker, 1977; Baird and Vickers-Rich, 1997). Likewise, assignment to the Cuculidae of Dynamopterus velox MilneEdwards, 1892, from an unknown locality of the Quercy fissure fillings in France, still has to be supported with derived characteristics, and the humerus of this species, the only known skeletal element, shows little resemblance to that of extant Cuculidae (pers. obs.). Neococcyx mccorquodalei Weigel, 1963 from the early Oligocene of North America appears to have been correctly identified as a Cuculidae but is based on a distal humerus only (Weigel, 1963). Among other features, cuckoos are characterized by obligate zygodactyly, i.e. the fourth toe is permanently retroverted. Sup-
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Fig. 5. Eocuculus cf. cherpinae Chandler, 1999, feet of referred specimen SMF Av 425 in comparison. 1. Right foot of specimen SMF Av 425 in dorsal view. 2. Right foot of plastotype of Eocuculus cherpinae Chandler, 1999 in dorsal view (specimen DM 10682). 3. Dorsal view of right tarsometatarsus of the extant Common Cuckoo, Cuculus canorus (Cuculidae). 4. Dorsal view of right tarsometatarsus of the extant Levaillant’s Cuckoo, Clamator levaillantii (Cuculidae). 5. Left foot of specimen SMF Av 425 in ventrolateral view. 6. Left foot of plastotype of Eocuculus cherpinae Chandler, 1999 in ventral view (specimen DM 10682). 7. Plantar view of left tarsometatarsus of the extant Common Cuckoo, Cuculus canorus (Cuculidae). 8. Plantar view of left tarsometatarsus of the extant Levaillant’s Cuckoo, Clamator levaillantii (Cuculidae). The toes are numbered. Abbreviations: fvd, foramen vasculare distale; fvp, medial foramen vasculare proximale; tac, trochlea accessoria; ttc, tuberositas musculi tibialis cranialis. Scale bars equal 10 mm.
posed presence of this character in E. cherpinae and a similar overall morphology to extant cuckoos appear to have been the reasons for Chandler (1999) to assign this species to Cuculidae, although no shared similarities were explicitly listed. Because of its short tarsometatarsus Chandler (1999) even assigned Eocuculus to a particular taxon within Cuculidae, the “arboreal cuckoos” (Cuculinae).
The new specimen from France shows that Eocuculus shares with extant Cuculidae a strongly cranially protruding apex carinae of the sternum and a markedly convex cranial margin of the carina sterni which are not found in any other extant small “land bird” taxon (Fig. 3). Also, the processus terminal ischii is wide and blunt as in extant Cuculidae and Musophagidae and not elongated and tapering as in most
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other small “land birds”. As exemplified by the more complete holotype of E. cherpinae (Fig. 2), the ulna of Eocuculus is further as long as the humerus, whereas it is longer than the humerus in most extant “higher land birds” (including parrots, Psittaciformes), and the furcula bears a well-developed apophysis furculae as in modern Cuculidae (Chandler, 1999: Fig. 3). However, of these similarities only the shape of the carina sterni is unquestionably derived within neornithine birds. The polarity of the shape of the processus terminal ischii is uncertain and a short ulna is a plesiomorphic feature that is also present in Mesozoic non-neornithine birds. Although Eocuculus more closely resembles cuckoos than any other extant avian taxon, it markedly differs from all crown group Cuculidae in several features. Most notably, the trochlea metatarsi IV bears no large trochlea accessoria which indicates that the foot of Eocuculus was semizygodactyl as that of extant Musophagidae rather than fully zygodactyl as in extant Cuculidae (contra Chandler, 1999). The pelvis further lacks even poorly developed tubercula praeacetabularia and the cranio-lateral edges of the alae praeacetabulares ilii are not pointed and protruding. Also, the dorsal surface of the distal end of the tarsometatarsus is convex, whereas it is essentially flat in crown group Cuculidae. The holotype of E. cherpinae further shows that the phalanx proximalis digiti majoris bears a well-developed processus internus indicis (Stegmann, 1963) which is invariably absent in extant Cuculidae. Apart from the latter feature and also with the possible exception of the lack of tubercula praeacetabularia (Mayr and Clarke, 2003), these characters are plesiomorphic for neornithine birds and show Eocuculus to be outside crown group Cuculidae. Thus, Eocuculus is at best a stem lineage member of Cuculidae and not within the crown group (contra Chandler, 1999). As detailed by Mayr (2005a) such a distinction is important because of the increasing use of fossil taxa for calibration of avian molecular clocks. Although Eocuculus provides a minimum date for the divergence of cuckoos from their sister taxon if future more complete skeletons prove its cuculiform affinities, it does not allow calibration of any divergences within crown group Cuculidae, which are unknown from Paleogene fossil localities. Judging from the proportions of its hind limb elements, Eocuculus probably was a non-terrestrial, possibly arboreal taxon as assumed by Chandler (1999). If it is a stem lineage representative of the Cuculidae, its morphology is thus at odds with the recently proposed hypothesis that the stem species of cuckoos was a terrestrial bird (Hughes, 2000; see also Aragón et al., 1999; Sorenson and Payne, 2002). Recognition of Eocuculus in the early Oligocene of France provides further evidence for the presence of an extinct late Eocene/early Oligocene “land bird” taxon with an intercontinental Northern Hemisphere distribution (another example can be found in Mourer-Chauviré, 1985). As is the case with all other fossil taxa yet described from the “Calcaires lithographiques” of the Luberon area, Eocuculus is unknown from the early Oligocene deposits of the geographically close and well-studied Quercy fissure fillings, which
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either indicates a different paleohabitat of these localities or taphonomic biases in the preservation of avian fossils. Acknowledgements I thank S. Tränkner for taking the photographs of the French specimen and R. Chandler for providing photographs of the holotype of E. cherpinae. I further thank C. Mourer-Chauviré and U. Göhlich for reviewing the manuscript. References Aragón, S., Møller, A.P., Soler, J.J., Soler, M., 1999. Molecular phylogeny of cuckoos supports a polyphyletic origin of brood parasitism. Journal of Evolutionary Biology 12, 495–506. Baird, R.F., Vickers-Rich, P., 1997. Eutreptodactylus itaboraiensis gen. and sp. nov., an early cuckoo (Aves: Cuculiformes) from the Late Paleocene of Brazil. Alcheringa 21, 123–127. Baumel, J.J., Witmer, L.M., 1993. Osteologia. In: Baumel, J.J., King, A.S., Breazile, J.E., Evans, H.E., Vanden Berge, J.C. (Eds.), Handbook of avian anatomy: Nomina anatomica avium. Publications of the Nuttall Ornithological Club 23, Cambridge. pp. 45–132. Berger, A.J., 1960. Some anatomical characters of the Cuculidae and the Musophagidae. Wilson Bulletin 72, 60–104. Bessonat, G., Michaut, A., 1973. Découverte d’un squelette complet d’échassier dans le Stampien provençal. Bulletin du Muséum d’Histoire Naturelle de Marseille 33, 143–145. Chandler, R.M., 1999. Fossil birds of Florissant, Colorado: with a description of a new genus and species of cuckoo. Geologic Resources Division Technical Report NPS/NRGRD/GRDTR-99, 49–53. Harrison, C.J.O., Walker, C.A., 1977. Birds of the British Lower Eocene. Tertiary Research Special Papers 3, 1–52. Hughes, J.M., 2000. Monophyly and phylogeny of cuckoos (Aves, Cuculidae) inferred from osteological characters. Zoological Journal of the Linnean Society 130, 263–307. Legendre, S., Lévêque, F., 1997. Étalonnage de l’échelle biochronologique mammalienne du Paléogène d’Europe occidentale : vers une intégration à l’échelle globale. In: Aguilar, J.-P., Legendre, S., Michaux, J. (Eds.), Actes du Congrès BiochroM’97. Mémoires et Travaux de l’École Pratique des Hautes Études, Institut de Montpellier 21. pp. 461–473. Lutz, H., 1984. Beitrag zur Kenntnis der Unteroligozänen Insektenfauna von Céreste (Süd-Frankreich). Documenta Naturae 21, 1–26. Mayr, G., 1999. A new trogon from the Middle Oligocene of Céreste, France. Auk 116, 427–434. Mayr, G., 2000. Charadriiform birds from the early Oligocene of Céreste (France) and the Middle Eocene of Messel (Hessen, Germany). Geobios 33, 625–636. Mayr, G., 2001. A second skeleton of the early Oligocene trogon Primotrogon wintersteini Mayr, 1999 (Aves: Trogoniformes: Trogonidae) in an unusual state of preservation. Senckenbergiana Lethaea 81, 335–338. Mayr, G., 2005a. The Paleogene fossil record of birds in Europe. Biological Reviews 80, 515–542. Mayr, G., 2005b. A chicken-sized crane precursor from the early Oligocene of France. Naturwissenschaften 92, 389–393. Mayr, G., 2005c. Phylogenetic affinities and composition of the early Eocene Gracilitarsidae (Aves? Piciformes). Neues Jahrbuch für Geologie und Paläontologie, Monatshefte 2005, 1–16. Mayr, G., Clarke, J., 2003. The deep divergences of neornithine birds: a phylogenetic analysis of morphological characters. Cladistics 19, 527–553. Mayr, G., Daniels, M., 1998. Eocene parrots from Messel (Hessen, Germany) and the London Clay of Walton-on-the-Naze (Essex, England). Senckenbergiana Lethaea 78, 157–177. Mayr, G., Mourer-Chauviré, C., 2005. A specimen of Parvicuculus Harrison and Walker, 1977 (Aves: Parvicuculidae) from the early Eocene of France. Bulletin of the British Ornithologists’ Club 125, 299–304.
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