Daniel Field

Comparative anatomy of the passerine carpometacarpus helps illuminate the early fossil record of crown Passeriformes.

Publisher: Wiley

Date: 07-09-2022

DOI: 10.1111/JOA.13761

Abstract: The hyper- erse clade Passeriformes (crown group passerines) comprises over half of extant bird ersity, yet disproportionately few studies have targeted passerine comparative anatomy on a broad phylogenetic scale. This general lack of research attention hinders efforts to interpret the passerine fossil record and obscures patterns of morphological evolution across one of the most erse clades of extant vertebrates. Numerous potentially important crown passeriform fossils have proven challenging to place phylogenetically, due in part to a paucity of phylogenetically informative characters from across the passerine skeleton. Here, we present a detailed analysis of the morphology of extant passerine carpometacarpi, which are relatively abundant components of the passerine fossil record. We s led >70% of extant family-level passerine clades (132 extant species) as well as several fossils from the Oligocene of Europe and scored them for 54 phylogenetically informative carpometacarpus characters optimised on a recently published phylogenomic scaffold. We document a considerable amount of previously undescribed morphological variation among passerine carpometacarpi, and, despite high levels of homoplasy, our results support the presence of representatives of both crown Passeri and crown Tyranni in Europe during the Oligocene.

Timing the extant avian radiation: The rise of modern birds, and the importance of modeling molecular rate variation

Publisher: PeerJ

Date: 06-02-2019

DOI: 10.7287/PEERJ.PREPRINTS.27521V1

Abstract: Unravelling the phylogenetic relationships among the major groups of living birds has been described as the greatest outstanding problem in dinosaur systematics. Recent work has identified portions of the avian tree of life that are particularly challenging to reconstruct, perhaps as a result of rapid cladogenesis early in crown bird evolutionary history (specifically, the interval immediately following the end-Cretaceous mass extinction). At face value this hypothesis enjoys support from the crown bird fossil record, which documents the first appearances of most major crown bird lineages in the early Cenozoic—in line with a model of rapid post-extinction niche filling among surviving avian lineages. However, molecular-clock analyses have yielded strikingly variable estimates for the age of crown birds, and conflicting inferences on the impact of the end-Cretaceous mass extinction on the extant bird radiation. This uncertainty has often been ascribed to a patchy avian fossil record, but the possibility of model misspecification in molecular ergence time analyses represents an important and relatively underexplored alternative hypothesis. Here, we highlight the necessity of further developing and using models that account for coordinated variation in rates of molecular evolution across a phylogeny (e.g. molecular early bursts) as a means of assessing support for a rapid post-Cretaceous radiation of crown birds. We discuss how relationships between life-history and substitution rates can mislead ergence time studies that do not account for directional changes in substitution rates over time, and suggest that these effects might have caused some of the variation in existing molecular date estimates for birds. We suggest multiple paths forward that could help resolve this and similar conflicts within other major eukaryotic clades.

Earth history and the passerine superradiation

Publisher: Proceedings of the National Academy of Sciences

Date: 04-2019

DOI: 10.1073/PNAS.1813206116

Abstract: Avian ersification has been influenced by global climate change, plate tectonic movements, and mass extinction events. However, the impact of these factors on the ersification of the hyper erse perching birds (passerines) is unclear because family level relationships are unresolved and the timing of splitting events among lineages is uncertain. We analyzed DNA data from 4,060 nuclear loci and 137 passerine families using concatenation and coalescent approaches to infer a comprehensive phylogenetic hypothesis that clarifies relationships among all passerine families. Then, we calibrated this phylogeny using 13 fossils to examine the effects of different events in Earth history on the timing and rate of passerine ersification. Our analyses reconcile passerine ersification with the fossil and geological records suggest that passerines originated on the Australian landmass ∼47 Ma and show that subsequent dispersal and ersification of passerines was affected by a number of climatological and geological events, such as Oligocene glaciation and inundation of the New Zealand landmass. Although passerine ersification rates fluctuated throughout the Cenozoic, we find no link between the rate of passerine ersification and Cenozoic global temperature, and our analyses show that the increases in passerine ersification rate we observe are disconnected from the colonization of new continents. Taken together, these results suggest more complex mechanisms than temperature change or ecological opportunity have controlled macroscale patterns of passerine speciation.

Yale University

Location: United States of America

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Smithsonian National Museum Of Natural History

Location: United States of America

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University Of Bath

Location: United Kingdom of Great Britain and Northern Ireland

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University Of British Columbia

Location: Canada

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University Of Cambridge

Location: United Kingdom of Great Britain and Northern Ireland

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University Of Cambridge University Museum Of Zoology

Location: United Kingdom of Great Britain and Northern Ireland

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University Of Cambridge

Location: No location found

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Discovery Projects - Grant ID: DP230100613

Start Date: 10-2023

End Date: 10-2026

Amount: $467,058.00

Funder: Australian Research Council