Vegavis is agenus of extinctbird that lived inAntarctica during theMaastrichtian stage of theLate Cretaceous. Thetype andonly species isVegavis iaai, representing one of the earliest knowncrown group birds. Initially described as member ofAnseriformes withinGalloanserae, the definitive taxonomic position ofVegavis was debated among paleontologists over two decades until the 2025 description of a nearly complete skull, discovered in 2011, supported its original classification.
Size (upper right) compared to contemporary birds,pterosaurs, and a human
The genus name,Vegavis, is a combination of the name ofVega Island and "avis", the Latin word for bird, while the species name, "iaai", is after theacronym for Instituto Antartico Argentino (IAA), the Argentine scientific expedition to Antarctica.[2] Theholotype is held by theMuseo de La Plata,Argentina.[3] The specimen, cataloged as MLP 93-I-3-1, was found in 1993 from theLópez de Bertodano Formation atCape Lamb onVega Island, Antarctica, and was first thought to be an indeterminatepresbyornithid.[4] It was only described as a new species in 2005, because it consists of the very delicate remains of one bird embedded in aconcretion, 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.[3] It was preserved in three dimensions, so CT scans were again utilized to visualize the intactsyrinx of this specimen. The syrinx has an asymmetrical third segment, suggesting thatVegavis 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 otherbasalneognaths.[5] Other potential specimens have also been reported, including a distal tarsometatarsus (AMNH FARB 30913) tentatively identified as cf.Vegavis,[6] an isolated femur (SDSM 78247) referred to asVegavis sp.,[7] and a synsacrum (MN 7832-V) referred to as cf.V. iaai.[8]
After 20 years since the formal naming ofVegavis, a nearly complete skull specimen (AMNH FARB 30899) discovered by Eric M. Roberts in 2011 from the López de Bertodano Formation was officially described in 2025. The morphology of this skull supports the placement ofVegavis within crown-groupAves, specifically as a member of theAnseriformes, and provides novel insight into its feeding ecology.[9]
Vegavis was initially described as a member of the crown groupAnseriformes withinGalloanserae, indicating that some representatives of the modern bird groups lived in theMesozoic.[2]
However, some paleontologists questioned its affinities toAnseriformes orGalloanserae,[10] with some classifying it as a stem-group bird withinOrnithurae,[11] a crown group bird outside Galloanserae,[3][12] a sister taxon of theNeornithes or at the base ofNeognathae with an unresolved position.[13] In contrast,Vegavis was recovered as a sister taxon ofAnatidae orAnseriformes withinGalloanserae based on phylogenetic analyses in 2024.[14][15] In a 2025 study which described a nearly complete skull ofVegavis, Torres et al. supported its placement within crown groupAnseriformes, sister toConflicto andAnas, based on their revised phylogenetic analyses.[9]
Agnolín et al. (2017) proposed the familyVegaviidae as stem-group Anseriformes containingVegavis,Polarornis and several other extinct avian genera,[16] but the monophyly of this clade was questioned by subsequent studies.[10][9] The fragmentaryPolarornis might possibly belong to this clade, but the reported specimens are poorly preserved to resolve its taxonomic affinities.[9] Worthy et al. (2017) also proposed the order "Vegaviiformes" to include Vegaviidae,[17] but this is a disused clade that has never been mentioned by other researchers except for the describers ofConflicto antarcticus.[18][19]
Vegavis was a bird with a high metabolism, which allowed it to live at high latitudes in Antarctica. It also shows a degree ofosteosclerosis, a condition shared withPolarornis. This different degrees of osteosclerosis could be related to variations in diving behaviour.[20]
^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.S2CID250577048.
^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.ISSN0002-7014.
^abcdTorres, Christopher R.; Clarke, Julia A.; Groenke, Joseph R.; Lamanna, Matthew C.; MacPhee, Ross D. E.; Musser, Grace M.; Roberts, Eric M.; O’Connor, Patrick M. (2025). "Cretaceous Antarctic bird skull elucidates early avian ecological diversity".Nature.638 (8049):146–151.doi:10.1038/s41586-024-08390-0.ISSN1476-4687.
^abMayr, 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.S2CID134876425.
^Álvarez-Herrera, G. P.; Rozadilla, S.; Agnolín, F. L.; Novas, F. E. (2024). "Jaw anatomy ofVegavis 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.S2CID259955013.
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