Cuculiformes Cuckoos

Although the zygodactyl Cuculiformes have a worldwide distribution today, their evolutionary history is virtually unknown and the fossil record is very poor. A putative cuckoo, Dynamopterus velox Milne-Edwards, 1892, is based on a humerus from an unknown horizon of the Quercy fissure fillings (Mourer-Chauvire 2006). Its identification needs to be confirmed by additional skeletal elements, as this fairly large bone, which is here figured for the first time (Fig. 11.1), is distinguished in a number of features from the humerus of extant Cuculiformes. From the late Eocene (Chadronian) of Canada, Weigel (1963) described Neococcyx mccorquodalei. The holotype of this species is a distal humerus of a bird the size of the extant Yellow-billed Cuckoo (Coccyzus ameri-canus). Identification of this fossil as a cuckoo may be correct, but the specimen has not been compared with the coeval Eocuculus cherpinae. This latter species was reported by Chandler (1999) from the late Eocene of the Florissant Fossil Beds of Colorado, and a very similar fossil from the early Oligocene of the Luberon area in France was classified as E. cf. cherpinae by Mayr (2006d, 2008a). Both records consist of postcranial skeletons. Eocuculus is possibly a stem group representative of the Cuculiformes, with which it shares, in addition to a similar overall shape of most bones, a strongly cranially protruding tip and markedly convex cranial margin of the sternal carina. Further, the ulna is as long as the humerus, whereas it is longer than this bone in most extant "higher land birds." As in extant Cuculiformes, the furcula has a well-developed apophysis

Dynamopterus

Fig. 11.1 a Right humerus of Dynamopterus velox Milne-Edwards, 1892 from an unknown horizon of the Quercy fissure fillings (cast of the holotype in the Natural History Museum, London, UK, BMNH A 5336); b right humerus of the Goliath Coucal, Centropus goliath (Cuculiformes); c right humerus of the Red-crested Turaco, Tauraco erythrolophus (Musophagiformes); d left tarsometatarsus of Parvicuculus minor Harrison and Walker, 1977 from the early Eocene London Clay (holotype, BMNH A 4919); e left tarsometatarsus of Parvicuculus cf. minor from the early Eocene of Condé-en-Brie, France (Muséum National d'Histoire Naturelle, Paris, France, MNHN-CB-17345). Same scale bars for a-c and d and e. (e Courtesy of Cécile Mourer-Chauviré, other photos by Sven Tränkner)

Dynamopterus

Fig. 11.1 a Right humerus of Dynamopterus velox Milne-Edwards, 1892 from an unknown horizon of the Quercy fissure fillings (cast of the holotype in the Natural History Museum, London, UK, BMNH A 5336); b right humerus of the Goliath Coucal, Centropus goliath (Cuculiformes); c right humerus of the Red-crested Turaco, Tauraco erythrolophus (Musophagiformes); d left tarsometatarsus of Parvicuculus minor Harrison and Walker, 1977 from the early Eocene London Clay (holotype, BMNH A 4919); e left tarsometatarsus of Parvicuculus cf. minor from the early Eocene of Condé-en-Brie, France (Muséum National d'Histoire Naturelle, Paris, France, MNHN-CB-17345). Same scale bars for a-c and d and e. (e Courtesy of Cécile Mourer-Chauviré, other photos by Sven Tränkner)

(Mayr 2008a). However, and in addition to other differences (Mayr 2006d), the tarsometatarsal trochlea for the fourth toe does not bear a large accessory troch-lea, and in contrast to extant Cuculiformes, Eocuculus thus probably only had semizygodactyl feet (Mayr 2006d).

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