''Intiornis'' (meaning "

Inti INTI International University & Colleges are private university colleges located in Malaysia. The main campus was initially known as INTI University College until 31 May 2010 when the Higher Education Ministry announced its upgrade to universi ...

bird", the binominal naming means "Unexpected Sun bird") is an extinct

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 ...

avisaurid Avisauridae is a family of extinct enantiornithine dinosaurs from the Cretaceous period, distinguished by several features of their ankle bones. Depending on the definition used, Avisauridae is either a broad and widespread group of advanced ena ...

enantiornithean The Enantiornithes, also known as enantiornithines or enantiornitheans in literature, are a group of extinct avialans ("birds" in the broad sense), the most abundant and diverse group known from the Mesozoic era. Almost all retained teeth and cl ...

birds which existed in what is now North-West

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 ...

during the late

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 ...

period (

Campanian The Campanian is the fifth of six ages of the Late Cretaceous Epoch on the geologic timescale of the International Commission on Stratigraphy (ICS). In chronostratigraphy, it is the fifth of six stages in the Upper Cretaceous Series. Campani ...

age).

Description

The genus is known from a partial hind limb found in beds of the

Upper 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'', ...

Las Curtiembres Formation. Three primary toes on a limb of ''Intiornis'' are nearly the same length. It was named by Fernando Emilio Novas, Federico Lisandro Agnolín and Carlos Agustín Scanferla in

2010 File:2010 Events Collage New.png, From top left, clockwise: The 2010 Chile earthquake was one of the strongest recorded in history; The Eruption of Eyjafjallajökull in Iceland disrupts air travel in Europe; A scene from the opening ceremony of ...

, and the type species is ''Intiornis inexpectatus''. With the body length of around ''Intiornis'' was the size of a

sparrow Sparrow may refer to: Birds * Old World sparrows, family Passeridae * New World sparrows, family Passerellidae * two species in the Passerine family Estrildidae: ** Java sparrow ** Timor sparrow * Hedge sparrow, also known as the dunnock or hedg ...

, thus representing the smallest enantiornithes known from

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the souther ...

. Its closest relative was ''

Soroavisaurus ''Soroavisaurus'' is a genus of enantiornithean birds related to ''Avisaurus''. It lived during the Late Cretaceous of Argentina. The only known species, ''S. australis'', is known from fossils collected from the Lecho Formation (Maastrichtian ...

'' from the

Lecho Formation The Lecho Formation is a geological formation in the Salta Basin of the provinces Jujuy and Salta of northwestern Argentina. Its strata date back to the Early Maastrichtian, and is a unit of the Salta Group. The fine-grained bioturbated s ...

(

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 ...

age) of northwestern Argentina.

Phylogeny

The cladogram below is from Wang ''et al.'', 2022: Key to letters: ''b'' = ''

Boluochia ''Boluochia zhengi'' was an enantiornithine bird. It lived during the Early Cretaceous in the time span 121.6-110.6 mya ( late Aptian- early Albian) and is known from fossils found in the Jiufotang Formation of Liaoning province, People's Repub ...

''
''c'' = ''

Cathayornis ''Cathayornis'' is a genus of enantiornithean birds from the Jiufotang Formation of Liaoning, People's Republic of China. It is known definitively from only one species, ''Cathayornis yandica'', one of the first Enantiornithes found in China. Se ...

''
''e'' = ''

Enantiophoenix ''Enantiophoenix'' is a genus of enantiornithine The Enantiornithes, also known as enantiornithines or enantiornitheans in literature, are a group of extinct avialans ("birds" in the broad sense), the most abundant and diverse group known fro ...

''
''f'' = ''

Houornis ''Houornis'' is a genus of enantiornithean birds from the Jiufotang Formation of Liaoning, People's Republic of China. It is known from a single species, ''Houornis caudatus'', which had been once been classified as a species of ''Cathayornis'' ...

''
''h'' = ''

Longipteryx ''Longipteryx'' is a genus of prehistoric bird which lived during the Early Cretaceous (Aptian stage, 120.3 million years ago). It contains a single species, ''Longipteryx chaoyangensis''. Its remains have been recovered from the Jiufotang Forma ...

''
''i'' = ''

Parabohaiornis ''Parabohaiornis'' is an extinct genus of bohaiornithid enantiornithean dinosaur known from the Early Cretaceous of Liaoning Province, northeastern China. It contains a single species, ''Parabohaiornis martini''. Discovery ''Parabohaiornis'' w ...

''
''j'' = '' Pterygornis''
''l'' = ''

Vorona ''Vorona'' ( ; Malagasy for "bird", ''V. berivotrensis'', "from Berivotra") is a monotypic genus of prehistoric birds. It was described from fossils found in a Maevarano Formation quarry near the village of Berivotra, Mahajanga Province, Ma ...

''
''m'' = '' Yuanjiawaornis''
''n'' = ''

Yungavolucris ''Yungavolucris'' is a genus of enantiornithean birds. It contains the single species ''Yungavolucris brevipedalis'', which lived in the Late Cretaceous (Maastrichtian, c.70.6 – 66 mya). The fossil bones were found in the Lecho Formation at ' ...

Paleobiology

Long toes of equal length and large curved claws suggest adaptability for perching.

References

Avisaurids Campanian life Cretaceous birds of South America Late Cretaceous animals of South America Cretaceous Argentina Fossils of Argentina Fossil taxa described in 2010 {{paleo-bird-stub