''Vegavis'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial n ...

of extinct

bird Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweig ...

that lived during the

Late Cretaceous The Late Cretaceous (100.5–66 Ma) is the younger of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''creta'', ...

(

Maastrichtian The Maastrichtian () is, in the ICS geologic timescale, the latest age (uppermost stage) of the Late Cretaceous Epoch or Upper Cretaceous Series, the Cretaceous Period or System, and of the Mesozoic Era or Erathem. It spanned the interv ...

stage) of

Antarctica Antarctica () is Earth's southernmost and least-populated continent. Situated almost entirely south of the Antarctic Circle and surrounded by the Southern Ocean, it contains the geographic South Pole. Antarctica is the fifth-largest co ...

, some 68 to 66

mya Mya may refer to: Brands and product names * Mya (program), an intelligent personal assistant created by Motorola * Mya (TV channel), an Italian Television channel * Midwest Young Artists, a comprehensive youth music program Codes * Burmese ...

. Among modern birds, most studies show that ''Vegavis'' is most closely related to

duck Duck is the common name for numerous species of waterfowl in the family Anatidae. Ducks are generally smaller and shorter-necked than swans and geese, which are members of the same family. Divided among several subfamilies, they are a fo ...

s and

geese A goose ( : geese) is a bird of any of several waterfowl species in the family Anatidae. This group comprises the genera ''Anser'' (the grey geese and white geese) and '' Branta'' (the black geese). Some other birds, mostly related to the she ...

(

Anatidae The Anatidae are the biological family of water birds that includes ducks, geese, and swans. The family has a cosmopolitan distribution, occurring on all the world's continents except Antarctica. These birds are adapted for swimming, floating ...

), but it is not considered to be a direct ancestor of them, Supporting information
/ref> although other studies question these results.

Taxonomy

The

holotype A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of seve ...

specimen of ''Vegavis'' is held by the Museo de La Plata,

Argentina Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an area of , making it the second-largest country in South America after Brazil, t ...

. The specimen, cataloged as MLP 93-I-3-1, was found in the López de Bertodano Formation at Cape Lamb on

Vega Island Vega Island is a small island to the northwest of James Ross Island, on the Antarctic Peninsula. It is separated from James Ross Island by Herbert Sound. The island was named by Otto Nordenskjold, leader of the Swedish Antarctic Expedition (190 ...

, 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 A concretion is a hard, compact mass of matter formed by the precipitation of mineral cement within the spaces between particles, and is found in sedimentary rock or soil. Concretions are often ovoid or spherical in shape, although irregular ...

, 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. The genus name, ''Vegavis'', is a combination of the name of

and "avis", the Latin word for bird. The species name, "iaai", is after the

acronym An acronym is a word or name formed from the initial components of a longer name or phrase. Acronyms are usually formed from the initial letters of words, as in '' NATO'' (''North Atlantic Treaty Organization''), but sometimes use syllables, a ...

for Instituto Antartico Argentino (IAA), the Argentine scientific expedition to Antarctica. 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 In classical Greek mythology, Syrinx (Greek Σύριγξ) was a nymph and a follower of Artemis, known for her chastity. Pursued by the amorous god Pan, she ran to a river's edge and asked for assistance from the river nymphs. In answer, s ...

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 Basal or basilar is a term meaning ''base'', ''bottom'', or ''minimum''. Science * Basal (anatomy), an anatomical term of location for features associated with the base of an organism or structure * Basal (medicine), a minimal level that is nec ...

neognaths Neognathae (; ) is a infraclass of birds, called neognaths, within the class Aves of the clade Archosauria. Neognathae includes the majority of living birds; the exceptions being the tinamous and the flightless ratites, which belong instead t ...

. 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.

Evolution

The discovery of the

type species In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specimen( ...

, ''Vegavis iaai'', demonstrates that the major groups of bird alive today had already diversified in the

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of ...

. 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 The Mesozoic Era ( ), also called the Age of Reptiles, the Age of Conifers, and colloquially as the Age of the Dinosaurs is the second-to-last era of Earth's geological history, lasting from about , comprising the Triassic, Jurassic and Creta ...

Paleobiology

''Vegavis'' was a bird with high metabolism, which allowed it to live at high latitudes in Antarctica. It also shows a degree of

osteosclerosis Osteosclerosis is a disorder that is characterized by abnormal hardening of bone and an elevation in bone density. It may predominantly affect the medullary portion and/or cortex of bone. Plain radiographs are a valuable tool for detecting and ...

, a condition shared with '' Polarornis''. This different degrees of osteosclerosis could be related to variations in diving behaviour.

References

External links

'Dinosaurs Mingled with Cousins of Ducks and Chickens', from Live Science

‘These Are the Dinosaurs That Didn't Die’, from National Geographic
{{Taxonbar, from=Q2319226 Prehistoric bird genera Cretaceous birds of Antarctica Fossils of Antarctica Fossil taxa described in 2005

Taxonomy

Evolution

Paleobiology

See also

References

External links