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Vegavis; Temporal range: Maastrichtian; ~69.2–68.4 Ma PreꞒ Ꞓ O S D C P T J K Pg N ↓
	Fossils displayed in Japan
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Aves
Order:	†Vegaviiformes
Family:	†Vegaviidae
Genus:	†Vegavis; Clarke et al. 2005
Species:	†V. iaai
Binomial name
	†Vegavis iaai; Clarke et al. 2005

Vegavis is a genus of extinct bird that lived in Antarctica during the Maastrichtian stage of the Late Cretaceous. The type species is Vegavis iaai. Vegavis was initially considered to be a member of Anseriformes within Galloanserae,^[2] but this claim has not been supported by some recent studies.^[3]^[4]^[5]

Taxonomy

The genus name, Vegavis, is a combination of the name of Vega Island and "avis", the Latin word for bird, while the species name, "iaai", is after the acronym for Instituto Antartico Argentino (IAA), the Argentine scientific expedition to Antarctica.^[2] The holotype is held by the Museo de La Plata, Argentina.^[6] The specimen, cataloged as MLP 93-I-3-1, was found in 1993 from the López de Bertodano Formation at Cape Lamb on Vega Island, Antarctica, and was first thought to be an indeterminate presbyornithid.^[7] It was only described as a new species in 2005, because it consists of the very delicate remains of one bird embedded in a concretion, which had to be meticulously prepared for study. CT scans were utilized to gain a clearer picture of the bone structure without running danger of damaging or destroying the fossil.^[2]

A second specimen, MACN-PV 19.748 (formerly MLP 93-I-3-2), was found beside the holotype specimen.^[6] It was preserved in three dimensions, so CT scans were again utilized to visualize the intact syrinx of this specimen. The syrinx has an asymmetrical third segment, suggesting that Vegavis had two sources of sound in the neck and along with large soft-tissue resonating structures. This indicates that it was likely capable of honks as in ducks, geese, and other basal neognaths.^[8] In 2019, a potential specimen SDSM 78247 was referred to as Vegavis sp.^[9]

Classification

Vegavis has been previously thought to be a member of the stem-group Anseriformes within Galloanserae, indicating that representatives of some of the groups of modern birds lived in the Mesozoic.^[2]^[10] However, some paleontologists questioned its affinities to Galloanserae and even its classification as a neornithine bird.^[11] McLachlan et al. (2017) considered the family Vegaviidae to be stem group birds within Ornithurae.^[12] Mayr et al. (2018) claimed that comparison of the plesiomorphic traits of the pterygoid and the mandible does not seem to firmly establish anseriform or galloanserine affinities for Vegaviidae.^[3] Field et al. (2020) considered Vegavis to be either a sister taxon to the Neornithes outside the crown group birds, or as a taxon at the base of Neognathae with an unresolved position.^[4] While other researchers have recovered Vegavis as a neornithine, they did not consider it to be a member of Anseriformes or Galloanserae, since they cannot find any diagnostic traits of those clades.^[6]^[5] In contrast, Vegavis was recovered as a sister taxon of Anatidae or Anseriformes based on phylogenetic analyses in 2024.^[13]^[14]

Paleobiology

Vegavis was a bird with a high metabolism, which allowed it to live at high latitudes in Antarctica. It also shows a degree of osteosclerosis, a condition shared with Polarornis. This different degrees of osteosclerosis could be related to variations in diving behaviour.^[15]

References

^ Roberts, E. M.; O'Connor, P. M.; Clarke, J. A.; Slotznick, S. P.; Placzek, C. J.; Tobin, T. S.; Hannaford, C.; Orr, T.; Jinnah, Z. A.; Claeson, K. M.; Salisbury, S.; Kirschvink, J. L.; Pirrie, D.; Lamanna, M. C. (2022). "New age constraints support a K/Pg boundary interval on Vega Island, Antarctica: Implications for latest Cretaceous vertebrates and paleoenvironments". GSA Bulletin. 135 (3–4): 867–885. doi:10.1130/B36422.1. S2CID 250577048.
^ ^a ^b ^c ^d Clarke, J.A.; Tambussi, C.P.; Noriega, J.I.; Erickson, G.M.; Ketcham, R.A. (2005). "Definitive fossil evidence for the extant avian radiation in the Cretaceous" (PDF). Nature. 433 (7023): 305–308. Bibcode:2005Natur.433..305C. doi:10.1038/nature03150. PMID 15662422. S2CID 4354309. Supporting information
^ ^a ^b Mayr, G.; De Pietri, V.L.; Scofield, R.P.; Worthy, T.H. (2018). "On the taxonomic composition and phylogenetic affinities of the recently proposed clade Vegaviidae Agnolín et al., 2017 ‒ neornithine birds from the Upper Cretaceous of the Southern Hemisphere)". Cretaceous Research. 86: 178–185. doi:10.1016/j.cretres.2018.02.013. hdl:2328/37887. S2CID 134876425.
^ ^a ^b Field, Daniel J.; Benito, Juan; Chen, Albert; Jagt, John W. M.; Ksepka, Daniel T. (18 March 2020). "Late Cretaceous neornithine from Europe illuminates the origins of crown birds". Nature. 579 (7799): 397–401. Bibcode:2020Natur.579..397F. doi:10.1038/s41586-020-2096-0. ISSN 1476-4687. PMID 32188952. S2CID 212937591.
^ ^a ^b Álvarez-Herrera, G. P.; Rozadilla, S.; Agnolín, F. L.; Novas, F. E. (2024). "Jaw anatomy of Vegavis iaai (Clarke et al., 2005) from the Late Cretaceous Antarctica, and its phylogenetic implications". Geobios. 83: 11–20. doi:10.1016/j.geobios.2023.03.004. S2CID 259955013.
^ ^a ^b ^c Acosta Hospitaleche C, Worthy TH (2021). "New data on the Vegavis iaai holotype from the Maastrichtian of Antarctica". Cretaceous Research. 124. 104818. Bibcode:2021CrRes.12404818A. doi:10.1016/j.cretres.2021.104818. S2CID 233703816.
^ Noriega, J.I.; Tambussi, C.P. (1995). "A Late Cretaceous Presbyornithidae (Aves: Anseriformes) from Vega Island, Antarctic Peninsula: Paleobiogeographic implications". Ameghiniana. 32 (1): 57–61. ISSN 0002-7014.
^ Clarke, J.A.; Chatterjee, S.; Li, Z.; Riede, T.; Agnolin, F.; Goller, F.; Isasi, M.P.; Martinioni, D.R.; Mussel, F.J.; Novas, F.E. (2016). "Fossil evidence of the avian vocal organ from the Mesozoic". Nature. 538 (7626): 502–505. Bibcode:2016Natur.538..502C. doi:10.1038/nature19852. PMID 27732575. S2CID 4389926.
^ Abagael R. West; Christopher R. Torres; Judd A. Case; Julia A. Clarke; Patrick M. O'Connor; Matthew C. Lamanna (2019). "An avian femur from the Late Cretaceous of Vega Island, Antarctic Peninsula: removing the record of cursorial landbirds from the Mesozoic of Antarctica". PeerJ. 7: e7231. doi:10.7717/peerj.7231. PMC 6626523. PMID 31333904.
^ ^a ^b Agnolín, F.L.; Egli, F.B.; Chatterjee, S.; Marsà, J.A.G (2017). "Vegaviidae, a new clade of southern diving birds that survived the K/T boundary". The Science of Nature. 104 (87): 87. Bibcode:2017SciNa.104...87A. doi:10.1007/s00114-017-1508-y. PMID 28988276. S2CID 253640553.
^ Acosta Hospitaleche, Carolina; Irazoqui, Facundo; Bona, Paula; Paulina-Carabajal, Ariana (2024). "Review of the Cretaceous avian diversity of Antarctica: a changing scenario for the evolution of early Neornithine birds". Advances in Polar Science. 35 (1): 1–13. doi:10.12429/j.advps.2023.0025.
^ Sandy M. S. McLachlan; Gary W. Kaiser; Nicholas R. Longrich (2017). "Maaqwi cascadensis: A large, marine diving bird (Avialae: Ornithurae) from the Upper Cretaceous of British Columbia, Canada". PLOS ONE. 12 (12): e0189473. Bibcode:2017PLoSO..1289473M. doi:10.1371/journal.pone.0189473. PMC 5722380. PMID 29220405.
^ Musser, G.; Clarke, J. A. (2024). "A new Paleogene fossil and a new dataset for waterfowl (Aves: Anseriformes) clarify phylogeny, ecological evolution, and avian evolution at the K-Pg Boundary". PLOS ONE. 19 (7). e0278737. doi:10.1371/journal.pone.0278737. PMC 11288464. PMID 39078833.
^ Crane, A.; Benito, J.; Chen, A.; Musser, G.; Torres, C. R.; Clarke, J. A.; Lautenschlager, S.; Ksepka, D. T.; Field, D. J. "Taphonomic damage obfuscates interpretation of the retroarticular region of the Asteriornis mandible". Geobios. doi:10.1016/j.geobios.2024.03.003.
^ Garcia, Jordi Alexis; Agnolín, Federico L.; Novas, Fernando (2019). "Bone microstructure of Vegavis iaai (Aves, Anseriformes) from the Upper Cretaceous of Vega Island, Antarctic Peninsula". Historical Biology. 31 (2): 163–167. Bibcode:2019HBio...31..163M. doi:10.1080/08912963.2017.1348503. S2CID 133907659.