Patterns of diversification and timing of evolution within Neoaves, which includes almost 95% of all bird species, are virtually unknown. On the other hand, molecular data consistently indicate a Cretaceous origin of many neoavian lineages and the fossil record seems to support an Early Tertiary diversification. Here, we present the first well-resolved molecular phylogeny for Neoaves, together with divergence time estimates calibrated with a large number of stratigraphically and phylogenetically welldocumented fossils. Our study defines several well-supported clades within Neoaves. The calibration results suggest that Neoaves, after an initial split from Galloanseres in Mid-Cretaceous, diversified around or soon after the K/T boundary. Our results thus do not contradict palaeontological data and show that there is no solid molecular evidence for an extensive preTertiary radiation of Neoaves.

Since birds are predominantly diurnal and often quite vociferous animals, their behavior and ecological requirements are probably better studied than those of any other vertebrate group. Detailed knowledge of their evolutionary history is, however, still limited to a small circle of specialists, and there is a widespread belief that the avian fossil record is poor. This is certainly true if the abundance of bird bones is compared with that of mammalian teeth, which are robust enough to survive even rough depositional environments and collection techniques. In many fossil localities complete skeletons and postcranial elements of birds are, however, not much rarer than those of other small land vertebrates. Numerous avian fossils in collections worldwide have remained further unstudied for decades, so the significant underrepresentation of birds in vertebrate paleontology seems to be due to a low number of specialists rather than a low number of fossils. Concerning certain geological periods and geographic areas, our knowledge of the early evolutionary history of birds is anything but poor. In fact, so many new fossils were described during the past two decades that it becomes increasingly difficult for a single person to cover the whole field of paleornithology. This book gives an account of the evolution of modern birds in the first half of the Cenozoic, aiming not only at specialists in the field of paleornithology, but also at ornithologists and paleontologists in need of detailed information, either for the calibration of molecular data or to set Paleogene faunas into a full context. Given the current pace of new discoveries, I am not cherishing the illusion that this survey will remain up to date for a long time. I do hope, however, that the overall framework outlined for the early diversity and evolution of modern birds will form a stable basis for future studies, and that the readers will find the book a useful source for their own research.

We describe the tenth skeletal specimen of the Upper Jurassic Archaeopterygidae. The almost complete and wellpreserved skeleton is assigned to Archaeopteryx siemensii Dames, 1897 and provides significant new information on the osteology of the Archaeopterygidae. As is evident from the new specimen, the palatine of Archaeopteryx was tetraradiate as in non-avian theropods, and not triradiate as in other avians. Also with respect to the position of the ectopterygoid, the data obtained from the new specimen lead to a revision of a previous reconstruction of the palate of Archaeopteryx . The morphology of the coracoid and that of the proximal tarsals is, for the first time, clearly visible in the new specimen. The new specimen demonstrates the presence of a hyperextendible second toe in Archaeopteryx . This feature is otherwise known only from the basal avian Rahonavis and deinonychosaurs (Dromaeosauridae and Troodontidae), and its presence in Archaeopteryx provides additional evidence for a close relationship between deinonychosaurs and avians. The new specimen also shows that the first toe of Archaeopteryx was not fully reversed but spread medially, supporting previous assumptions that Archaeopteryx was only facultatively arboreal. Finally, we comment on the taxonomic composition of the Archaeopterygidae and conclude that Archaeopteryx bavarica Wellnhofer, 1993 is likely to be a junior synonym of A. siemensii , and Wellnhoferia grandis El { anowski, 2001 a junior synonym of A. lithographica von Meyer, 1861.

Presumably, due to a rapid early diversification, major parts of the higher-level phylogeny of birds are still resolved controversially in different analyses or are considered unresolvable. To address this problem, we produced an avian tree of life, which includes molecular sequences of one or several species of ∼ 90% of the currently recognized family-level taxa (429 species, 379 genera) including all 106 for the non-passerines and 115 for the passerines (Passeriformes). The unconstrained analyses of noncoding 3-prime untranslated region (3’UTR) sequences and those of coding sequences yielded different trees. In contrast to the coding sequences, the 3’UTR sequences resulted in a well-resolved and stable tree topology. The 3’UTR contained, unexpectedly, transcription factor binding motifs that were specific for different higher-level taxa. In this tree, grebes and flamingos are the sister clade of all other Neoaves, which are subdivided into five major clades. All non-passerine taxa were placed with robust statistical support including the long-time enigmatic hoatzin (Opisthocomiformes), which was found being the sister taxon of the Caprimulgiformes. The comparatively late radiation of family-level clades of the songbirds (oscine Passeriformes) contrasts with the attenuated diversification of non-passeriform taxa since the early Miocene. This correlates with the evolution of vocal production learning, an important speciation factor, which is ancestral for songbirds and evolved convergent only in hummingbirds and parrots. Since 3’UTR-based phylotranscriptomics resolved the avian family-level tree of life, we suggest that this procedure will also resolve the all-species avian tree of life

The Paleogene (Paleocene-Oligocene) fossil record of birds in Europe is reviewed and recent and fossil taxa are placed into a phylogenetic framework, based on published cladistic analyses. The pre-Oligocene European avifauna is characterized by the complete absence of passeriform birds, which today are the most diverse and abundant avian taxon. Representatives of small non-passeriform perching birds thus probably had similar ecological niches before the Oligocene to those filled by modern passerines. The occurrence of passerines towards the Lower Oligocene appears to have had a major impact on these birds, and the surviving crown-group members of many small arboreal Eocene taxa show highly specialized feeding strategies not found or rare in passeriform birds. It is detailed that no crown-group members of modern 'families ' are known from preOligocene deposits of Europe, or anywhere else. The phylogenetic position of Paleogene birds thus indicates that diversification of the crown-groups of modern avian 'families ' did not take place before the Oligocene, irrespective of their relative position within Neornithes (crown-group birds). The Paleogene fossil record of birds does not even support crown-group diversification of Galliformes, one of the most basal taxa of neognathous birds, before the Oligocene, and recent molecular studies that dated diversification of galliform crown-group taxa into the Middle Cretaceous are shown to be based on an incorrect interpretation of the fossil taxa used for molecular clock calibrations. Several taxa that occur in the Paleogene of Europe have a very different distribution than their closest extant relatives. The modern survivors of these Paleogene lineages are not evenly distributed over the continents, and especially the great number of taxa that are today restricted to South and Central America is noteworthy. The occurrence of stem-lineage representatives of many taxa that today have a restricted Southern Hemisphere distribution conflicts with recent hypotheses on a Cretaceous vicariant origin of these taxa, which were deduced from the geographical distribution of the basal crown-group members.