35 research outputs found

    Current perspectives on the evolution of birds

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    The paper summarizes the current understanding of the evolution and diversification of birds. New insights into this field have mainly come from two fundamentally different, but complementary sources of information: the many newly discovered Mesozoic bird fossils and the wealth of genetic analyses of living birds at various taxonomic levels. The birds have evolved from theropod dinosaurs from which they can be defined by but a few morphological characters. The early evolutionary history of the group is characterized by the extinctions of many major clades by the end of the Cretaceous, and by several periods of rapid radiations and speciation. Recent years have seen a growing consensus about the higher-level relationships among living birds, at least as can be deduced from genetic data.</jats:p

    Molecular and morphological evidences place the extinct New Zealand endemic Turnagra capensis in the Oriolidae

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    The affinities of Piopio Turnagra capensis, an extinct New Zealand passerine, remain poorly known. It has been included into or associated with several bird families (Calleatidae, Cracticidae, Pachycephalidae, Ptilonorhynchidae, Turdidae), often on tenuous grounds. We reassessed Turnagra phylogenetic relationships using nuclear and mitochondrial sequences and a set of morphological and behavioural traits. Molecular and phenotypic characters strongly suggest a novel hypothesis, congruently placing Turnagra in Oriolidae, a highly dispersive corvoid family distributed from the Austro-Papuan landmass to Eurasia and Africa, but missing from the Pacific islands. We show also that the published molecular support to link Turnagra with Ptilonorhynchidae was biased by the use of incorrect genetic data and weak analyses.</p

    Data from: The complex phylogeography of the Indo-Malayan Alophoixus bulbuls with the description of a putative new ring species complex

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    The Indo-Malayan bioregion has provided some of the most spectacular discoveries of new vertebrate species (e.g. saola, khanyou, bare-faced bulbul) over the last 25 years. Yet, very little is known about the processes that led to the current biodiversity in this region. We reconstructed the phylogeographic history of a group of closely related passerines, the Alophoixus bulbuls. These birds are continuously distributed in Indo-Malaya around the Thailand lowlands such that their distribution resembles a ring. Our analyses revealed a single colonization event of the mainland from Sundaland with sequential divergence of taxa from southwest to northeast characterized by significant gene flow between parapatric taxa, and reduced or ancient gene flow involving the two taxa at the extremities of the ring. We detected evidence of population expansion in two subspecies, including one that was involved in the closing of the ring. Hence, our analyses indicate that the diversification pattern of Alophoixus bulbuls fits a ring species model driven by geographic isolation. To our knowledge, the Alophoixus bulbuls represent the first case of a putative broken ring species complex in Indo-Malaya. We also discuss the implications of our results on our understanding of the biogeography in Indo-Malaya

    A New Enantiornithes (Aves) from the Early Cretaceous of China

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    A new bird from the early Cretaceous Yixian Formation of Liaoning, China is described. This new species, Grabauornis lingyuanensis, shares several synapomorphies with the Enantiornithes. The specimen is relatively well preserved. The skeletal morphology of Grabauornis bears close resemblance to that of other Chinese members of this clade. The brachial index (the ratio between the lengths of humerus and ulna) is 0.95, which is close to the average for enantiornithine birds. It indicates that Grabauornis was a rather good flyer, and the presence of an alula in the wing further testifies to this.</p

    Phylogenetic utility and evolution of indels: A study in neognathous birds

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    Indels are increasingly used in phylogenetics and play a major role in genome size evolution, and yet both the phylogenetic information content of indels and their evolutionary significance remain to be better assessed. Using three presumably independently evolving nuclear gene fragments (28S rDNA, β-fibrinogen, ornithine decarboxylase) from 29 families of neognathous birds, we have obtained a topology that is in general agreement with the current molecular consensus tree, supports the monophyly of Metaves, and provides evidence for the unresolved relationships within the Charadriiformes. Based on the retrieved topology, we assess the relative impact of indels and nucleotide substitutions and demonstrate that the superposition of the two kinds of data yields a topology that could not be obtained from either data set alone. Although only two out of three gene fragments reveal the deletion bias, the combined nucleotide insertion-to-deletion ratio is 0.22, indicating a rapid decrease of intron length. The average indel fixation rate in the neognaths is 2.5 times faster than that in therian (placental) mammals of similar geologic age. As in mammals, there is a considerable variation of indel fixation rate that is 1.5 times higher in Galloanseres compared to Neoaves, and 2.4 times higher in the Rallidae compared to the average for Neoaves (8.2 times higher compared to the related Gruidae). Our results add to the evidence that indel fixation rates correlate with lineage-specific evolutionary rates.</p

    Systematic revision of the avian family Cisticolidae based on a multi-locus phylogeny of all genera

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    The avian taxon Cisticolidae includes c. 110 species which are distributed throughout the tropical and subtropical parts of the Old World. We estimated the phylogeny of 47 species representing all genera assumed to be part of Cisticolidae based on sequence data from two mitochondrial and two nuclear markers, in total 3495 bp. Bayesian inference and maximum likelihood analyses resulted in a generally well-supported phylogeny which clarified the position of several previously poorly known taxa. The placement of Drymocichla, Malcorus, Micromacronus, Oreophilais, Phragmacia, Phyllolais, Poliolais and Urorhipis in Cisticolidae is corroborated, whereas Rhopophilus and Scotocerca are removed from Cisticolidae. Urorhipis and Heliolais are placed in the genus Prinia whereas Prinia burnesii is shown to be part of Timaliidae, and is placed in the genus Laticilla. Although not recovered by all single loci independently, four major clades were identified within Cisticolidae, and one of these is here described as a new taxon (Neomixinae).</p

    En rovfågelsklo från Gamla Skogsby på Öland

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    This paper proceeds from the excavations by Linnaeus University in 2019–2023 of a Migration Period house foundation at Gamla Skogsby, Öland, SE Sweden, situated in what was originally a large village with one of the largest Migration Period farms recorded on the whole island. The house and the excavation results are presented in brief, and in particular, the find of a raptor claw inside the house is given special attention. The claw is evaluated osteologically, identified as the claw of an eagle and suggested as an indication of prestige related to the local elite at the site. This is followed by an attempt to place the find in a larger context, with an evaluation of the find as a possible indication of falconry at the site in the Migration Period. The role of eagles in falconry is examined and the implications for this in connection with the falconry hypothesis at Gamla Skogsby are discussed. The find and the settlement at which it was made are then analysed in relation to a larger landscape context including important artefact finds, burials, settlements and fortifications, and the possible role of women in relation to falconry is discussed
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