The debate on avian ancestry: phylogeny, function, and fossils / Lawrence M. Witmer -- Cladistic approaches to the relationships of birds to other theropod dinosaurs / James M. Clark, Mark A. Norell and Peter J. Makovicky -- The enigmatic birdlike dinosaur Avimimus portentosus: comments and a pictorial atlas / Patricia Vickers-Rich, Luis M. Chiappe and Sergei Kurzanov -- The Cretaceous short-armed Alvarezsauridae: Mononykus and its kin / Luis M. Chiappe, Mark A. Norell and James M. Clark -- Alvarezsaurid relationships reconsidered / Fernando E. Novas and Diego Pol -- Archaeopterygidae (Upper Jurassic of Germany) / Andrzej Elzanowski -- The discovery and study of Mesozoic birds in China / Zhou Zhonghe and Hou Lianhai -- Sinornis santensis (Aves: Enantiornithes) from the early Cretaceous of northeastern China / Paul C. Sereno, Rao Chenggang and Li Jianjun -- The birds from the Lower Cretaceous of Las Hoyas (Province of Cuenca, Spain) / Josโe L. Sanz ... [et al.] -- Nogueromis gonzalezi (Aves: Ornithothoraces) from the early Cretaceous of Spain / Luis M. Chiappe and Antonio Lacasa-Ruiz -- Skeletal morphology and systematics of the Cretaceous Euenantiornithes (Ornithothoraces: Enantiornithes) / Luis M. Chiappe and Cyril A. Walker -- Vorona berivotrensis, a primitive bird from the late Cretaceous of Madagascar / Catherine A. Forster ... [et al.] -- Osteology of the flightless Patagopteryx deferrariisi from the late Cretaceous of Patagonia (Argentina) / Luis M. Chiappe -- Enaliornis, an early Cretaceous hesperornithiform bird from England, with comments on other Hesperornithiformes / Peter M. Galton and Larry D. Martin --