Vegavis

Vegavis
Temporal range: Maastrichtian
~68–66 Ma
↓
Scientific classification
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 during the Late Cretaceous (Maastrichtian stage) of Antarctica, some 68 to 66 mya. Among modern birds, Vegavis is most closely related to ducks and geese (Anatidae), but it is not considered to be a direct ancestor of them.[1]

Etymology

The genus name, Vegavis, is a combination of the name of Vega Island and "avis", the Latin word for bird. The species name, "iaai", is after the acronym for Instituto Antartico Argentino (IAA), the Argentine scientific expedition to Antarctica.

Description

The discovery of the type species, Vegavis iaai, demonstrates that the major groups of bird alive today had already diversified in the Cretaceous. This supports the longstanding phylogenetic inferences of paleornithologists. It has been hailed as the first definitive physical proof that representatives of some of the groups of modern birds lived in the Mesozoic.[1]

Antarctopelta oliveroi and a bird like Vegavis iaai

The holotype specimen of Vegavis is held by the Museo de La Plata, Argentina. The specimen, cataloged as MLP 93-I-3-1, was found in the López de Bertodano Formation at Cape Lamb on Vega Island, Antarctica, in 1993, but 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.[1]

A second specimen, MACN-PV 19.748, was found beside the holotype specimen. It was preserved in three dimensions; 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.[2] In 2017 a phylogenetic study Agnolín and colleagues have found Vegavis to be stem-anseriforms along with Polarornis, Neogaeornis and Australornis in the family Vegaviidae.[3]

References

  1. 1 2 3 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. doi:10.1038/nature03150. PMID 15662422. Supporting information
  2. ↑ 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. doi:10.1038/nature19852. PMID 27732575.
  3. ↑ 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). doi:10.1007/s00114-017-1508-y.
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