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An avian femur from the Late Cretaceous of Vega Island, Antarctic Peninsula: removing the record of cursorial landbirds from the Mesozoic of Antarctica

In 2006, a partial avian femur (South Dakota School of Mines and Technology (SDSM) 78247) from the Upper Cretaceous (Maastrichtian) Sandwich Bluff Member of the López de Bertodano Formation of Sandwich Bluff on Vega Island of the northern Antarctic Peninsula was briefly reported as that of a cariami...

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Autores principales: West, Abagael R., Torres, Christopher R., Case, Judd A., Clarke, Julia A., O'Connor, Patrick M., Lamanna, Matthew C.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: PeerJ Inc. 2019
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6626523/
https://www.ncbi.nlm.nih.gov/pubmed/31333904
http://dx.doi.org/10.7717/peerj.7231
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author West, Abagael R.
Torres, Christopher R.
Case, Judd A.
Clarke, Julia A.
O'Connor, Patrick M.
Lamanna, Matthew C.
author_facet West, Abagael R.
Torres, Christopher R.
Case, Judd A.
Clarke, Julia A.
O'Connor, Patrick M.
Lamanna, Matthew C.
author_sort West, Abagael R.
collection PubMed
description In 2006, a partial avian femur (South Dakota School of Mines and Technology (SDSM) 78247) from the Upper Cretaceous (Maastrichtian) Sandwich Bluff Member of the López de Bertodano Formation of Sandwich Bluff on Vega Island of the northern Antarctic Peninsula was briefly reported as that of a cariamiform—a clade that includes extant and volant South American species and many extinct flightless and cursorial species. Although other authors have since rejected this taxonomic assignment, SDSM 78247 had never been the subject of a detailed description, hindering a definitive assessment of its affinities. Here we provide the first comprehensive description, illustration, and comparative study of this specimen. Comparison of characters that may be assessed in this femur with those of avian taxa scored in published character matrices refutes the inclusion of SDSM 78247 within Cariamiformes, instead supporting its assignment to a new, as-yet unnamed large-bodied species within the genus Vegavis, and therefore its referral to a clade of semiaquatic anseriforms. Important character states diagnostic of Vegavis + Polarornis include strong craniocaudal bowing of the femoral shaft, the presence of a distinct fossa just proximal to the fibular trochlea, and the broad and flat shape of the patellar sulcus. Referral to Vegavis is based on the presence of a distinctive proximocaudal fossa and distolateral scar. This genus was previously known only from Vegavis iaai, a smaller-bodied taxon from the same locality and stratigraphic unit. Our reassignment of SDSM 78247 to Vegavis sp. removes the record of cariamiform landbirds from the Antarctic Cretaceous.
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spelling pubmed-66265232019-07-22 An avian femur from the Late Cretaceous of Vega Island, Antarctic Peninsula: removing the record of cursorial landbirds from the Mesozoic of Antarctica West, Abagael R. Torres, Christopher R. Case, Judd A. Clarke, Julia A. O'Connor, Patrick M. Lamanna, Matthew C. PeerJ Biogeography In 2006, a partial avian femur (South Dakota School of Mines and Technology (SDSM) 78247) from the Upper Cretaceous (Maastrichtian) Sandwich Bluff Member of the López de Bertodano Formation of Sandwich Bluff on Vega Island of the northern Antarctic Peninsula was briefly reported as that of a cariamiform—a clade that includes extant and volant South American species and many extinct flightless and cursorial species. Although other authors have since rejected this taxonomic assignment, SDSM 78247 had never been the subject of a detailed description, hindering a definitive assessment of its affinities. Here we provide the first comprehensive description, illustration, and comparative study of this specimen. Comparison of characters that may be assessed in this femur with those of avian taxa scored in published character matrices refutes the inclusion of SDSM 78247 within Cariamiformes, instead supporting its assignment to a new, as-yet unnamed large-bodied species within the genus Vegavis, and therefore its referral to a clade of semiaquatic anseriforms. Important character states diagnostic of Vegavis + Polarornis include strong craniocaudal bowing of the femoral shaft, the presence of a distinct fossa just proximal to the fibular trochlea, and the broad and flat shape of the patellar sulcus. Referral to Vegavis is based on the presence of a distinctive proximocaudal fossa and distolateral scar. This genus was previously known only from Vegavis iaai, a smaller-bodied taxon from the same locality and stratigraphic unit. Our reassignment of SDSM 78247 to Vegavis sp. removes the record of cariamiform landbirds from the Antarctic Cretaceous. PeerJ Inc. 2019-07-10 /pmc/articles/PMC6626523/ /pubmed/31333904 http://dx.doi.org/10.7717/peerj.7231 Text en © 2019 West et al. http://creativecommons.org/licenses/by/4.0/ This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/) , which permits unrestricted use, distribution, reproduction and adaptation in any medium and for any purpose provided that it is properly attributed. For attribution, the original author(s), title, publication source (PeerJ) and either DOI or URL of the article must be cited.
spellingShingle Biogeography
West, Abagael R.
Torres, Christopher R.
Case, Judd A.
Clarke, Julia A.
O'Connor, Patrick M.
Lamanna, Matthew C.
An avian femur from the Late Cretaceous of Vega Island, Antarctic Peninsula: removing the record of cursorial landbirds from the Mesozoic of Antarctica
title An avian femur from the Late Cretaceous of Vega Island, Antarctic Peninsula: removing the record of cursorial landbirds from the Mesozoic of Antarctica
title_full An avian femur from the Late Cretaceous of Vega Island, Antarctic Peninsula: removing the record of cursorial landbirds from the Mesozoic of Antarctica
title_fullStr An avian femur from the Late Cretaceous of Vega Island, Antarctic Peninsula: removing the record of cursorial landbirds from the Mesozoic of Antarctica
title_full_unstemmed An avian femur from the Late Cretaceous of Vega Island, Antarctic Peninsula: removing the record of cursorial landbirds from the Mesozoic of Antarctica
title_short An avian femur from the Late Cretaceous of Vega Island, Antarctic Peninsula: removing the record of cursorial landbirds from the Mesozoic of Antarctica
title_sort avian femur from the late cretaceous of vega island, antarctic peninsula: removing the record of cursorial landbirds from the mesozoic of antarctica
topic Biogeography
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6626523/
https://www.ncbi.nlm.nih.gov/pubmed/31333904
http://dx.doi.org/10.7717/peerj.7231
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