Topic
Vegavis
About: Vegavis is a research topic. Over the lifetime, 7 publications have been published within this topic receiving 119 citations.
Papers
TL;DR: Trait analyses showed that while gigantism and flightlessness evolved repeatedly in groups, diet is constrained by phylogeny: all giant Galloanseres and palaeognaths are herbivores or mainly herbivorous, and giant neoavians are zoophagous or omnivorous.
Abstract: The extinct dromornithids, gastornithids and phorusrhacids are among the most spectacular birds to have ever lived, with some giants exceeding 500 kg. The affinities and evolution of these and other related extinct birds remain contentious, with previous phylogenetic analyses being affected by widespread convergence and limited taxon sampling. We address these problems using both parsimony and tip-dated Bayesian approaches on an expansive taxon set that includes all key extinct flightless and flighted (e.g. Vegavis and lithornithids) forms, an extensive array of extant fowl (Galloanseres), representative Neoaves and palaeognaths. The Paleogene volant Lithornithidae are recovered as stem palaeognaths in the Bayesian analyses. The Galloanseres comprise four clades inferred to have diverged in the Late Cretaceous on Gondwana. In addition to Anseriformes and Galliformes, we recognize a robust new clade (Gastornithiformes) for the giant flightless Dromornithidae (Australia) and Gastornithidae (Eurasia, North America). This clade exhibits parallels to ratite palaeognaths in that flight presumably was lost and giant size attained multiple times. A fourth clade is represented by the Cretaceous Vegavis (Antarctica), which was strongly excluded from Anseriformes; thus, a crucial molecular calibration point needs to be reconsidered. The presbyornithids Wilaru (Australia) and Presbyornis (Northern Hemisphere) are robustly found to be the sister group to Anatoidea (Anseranatidae + Anatidae), a relatively more basal position than hitherto recognized. South America's largest bird, Brontornis, is not a galloansere, but a member of Neoaves related to Cariamiformes; therefore, giant Galloanseres remain unknown from this continent. Trait analyses showed that while gigantism and flightlessness evolved repeatedly in groups, diet is constrained by phylogeny: all giant Galloanseres and palaeognaths are herbivores or mainly herbivorous, and giant neoavians are zoophagous or omnivorous.
98 citations
TL;DR: The first syrinX from the age of dinosaurs is described from a new specimen of Vegavis iaai from the Cretaceous period of Antarctica, and study of its fossilized syrinx shows that it would have been a 'honker', like its modern relatives.
Abstract: A discovery of the sound-producing vocal organ known as the syrinx in a bird fossil from the end of the 'age of dinosaurs' highlights the anatomical basis for myriad aspects of avian social and behavioural evolution. See Letter p.502
From tweets to honks, birds make sounds with the syrinx, an organ derived from a modification of the reinforced rings at the base of the trachea where it divides into bronchi. Apart from fragmentary remains from the Pleistocene and Holocene epochs, and a single find from the Eocene epoch that has not been formally described, the fossil record of the syrinx is blank. Here Julia Clarke et al. describe the first syrinx from the age of dinosaurs. It comes from a new specimen of Vegavis iaai from the Cretaceous period of Antarctica. Vegavis was a bird related to modern ducks and geese, and study of its fossilized syrinx shows that it would have been a 'honker', like its modern relatives.
TL;DR: Recognition of Vegaviidae indicates that modern birds were diversified in southern continents by the Cretaceous and reinforces the hypothesis indicating the important role of Gondwana for the evolutionary history of Anseriformes and Neornithes as a whole.
Abstract: The fossil record of Late Cretaceous–Paleogene modern birds in the Southern Hemisphere includes the Maastrichtian Neogaeornis wetzeli from Chile, Polarornis gregorii and Vegavis iaai from Antarctica, and Australornis lovei from the Paleogene of New Zealand. The recent finding of a new and nearly complete Vegavis skeleton constitutes the most informative source for anatomical comparisons among Australornis, Polarornis, and Vegavis. The present contribution includes, for the first time, Vegavis, Polarornis, and Australornis in a comprehensive phylogenetic analysis. This analysis resulted in the recognition of these taxa as a clade of basal Anseriformes that we call Vegaviidae. Vegaviids share a combination of characters related to diving adaptations, including compact and thickened cortex of hindlimb bones, femur with anteroposteriorly compressed and bowed shaft, deep and wide popliteal fossa delimited by a medial ridge, tibiotarsus showing notably proximally expanded cnemial crests, expanded fibular crest, anteroposterior compression of the tibial shaft, and a tarsometatarsus with a strong transverse compression of the shaft. Isolated bones coming from the Cretaceous and Paleogene of South America, Antarctica, and New Zealand are also referred to here to Vegaviidae and support the view that these basal anseriforms were abundant and diverse at high southern latitudes. Moreover, vegaviids represent the first avian lineage to have definitely crossed the K–Pg boundary, supporting the idea that some avian clades were not affected by the end Mesozoic mass extinction event, countering previous interpretations. Recognition of Vegaviidae indicates that modern birds were diversified in southern continents by the Cretaceous and reinforces the hypothesis indicating the important role of Gondwana for the evolutionary history of Anseriformes and Neornithes as a whole.
TL;DR: The results of the phylogenetic analysis suggest that A. capelambensis would be placed inside the Ornithuromorpha, and probably nested within the Ornithsurae, which would make it the geologically oldest bird described from Antarctica.
TL;DR: Plesiomorphic traits of the pterygoid and the mandible clearly show that Vegavis is not a representative of crown group Anseriformes, and it is pointed out that even anseriform or galloanserine affinities of Vegaviidae have not been firmly established.
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2020 | 1 |
| 2019 | 2 |
| 2018 | 1 |
| 2017 | 2 |
| 2016 | 1 |