''Proapteryx micromeros'' is an extinct

kiwi Kiwi most commonly refers to: * Kiwi (bird), a flightless bird native to New Zealand * Kiwi (nickname), a nickname for New Zealanders * Kiwifruit, an edible berry * Kiwi dollar or New Zealand dollar, a unit of currency Kiwi or KIWI may also ref ...

known from the 16–19 million-year-old early

Miocene The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recent" ...

sediments of the

St Bathans Fauna The St Bathans fauna is found in the lower Bannockburn Formation of the Manuherikia Group of Central Otago, in the South Island of New Zealand. It comprises a suite of fossilised prehistoric animals from the late Early Miocene (Altonian) period, w ...

Otago Otago (, ; mi, Ōtākou ) is a region of New Zealand located in the southern half of the South Island administered by the Otago Regional Council. It has an area of approximately , making it the country's second largest local government reg ...

New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 List of islands of New Zealand, smaller islands. It is the ...

Features

''P. micromeros'' is considerably smaller than modern kiwis, weighing around 234.1 – 377g (the smallest living kiwi, ''

Apteryx owenii The little spotted kiwi or little grey kiwi (''Apteryx owenii'') is a small flightless bird in the kiwi family Apterygidae. It is the smallest species of all five kiwis, at about , about the size of a bantam. It is endemic to New Zealand, and in ...

'', weighs at least 800 g), and its more gracile otic process may indicate a shorter bill. It bears distinctively slender hindlimbs, more comparable in terms of proportion to flying birds like the

banded rail The buff-banded rail (''Hypotaenidia philippensis'') is a distinctively coloured, highly dispersive, medium-sized rail of the rail family, Rallidae. This species comprises several subspecies found throughout much of Australasia and the south- ...

than to extant kiwis, and it is speculated to have been capable of powered flight, or to have evolved relatively recently from flying ancestors.

Importance

The fact that ''Proapteryx'' lacked specialisation for a terrestrial, flightless lifestyle supports the hypothesis that kiwi ancestors flew to New Zealand from Australia in the Miocene, well after

moa Moa are extinct giant flightless birds native to New Zealand. The term has also come to be used for chicken in many Polynesian cultures and is found in the names of many chicken recipes, such as Kale moa and Moa Samoa. Moa or MOA may also refe ...

s had developed their modern forms – moa remains are also known from Saint Bathans, already large and flightless.Worthy, T.H., Tennyson, A.J.D., Jones, C., McNamara, J.A. & Douglas B.J. (2007). "Miocene waterfowl and other birds from Central Otago, New Zealand". ''Journal of Systematic Palaeontology'', 5: 1–39. This supports genetic and morphological analyses indicating that the two clades arrived in New Zealand independently and are not particularly closely related, moas forming a clade with

tinamou Tinamous () form an order of birds called Tinamiformes (), comprising a single family called Tinamidae (), divided into two distinct subfamilies, containing 46 species found in Mexico, Central America, and South America. The word "tinamou" comes ...

s, and kiwis with Australian ratites, the

cassowary Cassowaries ( tpi, muruk, id, kasuari) are flightless birds of the genus ''Casuarius'' in the order Casuariiformes. They are classified as ratites (flightless birds without a keel on their sternum bones) and are native to the tropical ...

and

emu The emu () (''Dromaius novaehollandiae'') is the second-tallest living bird after its ratite relative the ostrich. It is endemic to Australia where it is the largest native bird and the only extant member of the genus '' Dromaius''. The ...

.Phillips, M.J., Gibb, G.C., Crimp, E.A. & Penny, D. (2010). "Tinamous and moa flock together: mitochondrial genome sequence analysis reveals independent losses of flight among ratites". ''Systematic Biology'', 59: 90–107. Kiwis have also been found by molecular studies to be the sister taxa of the

elephant bird Elephant birds are members of the extinct ratite family Aepyornithidae, made up of flightless birds that once lived on the island of Madagascar. They are thought to have become extinct around 1000-1200 CE, probably as a result of human activit ...

s of

Madagascar Madagascar (; mg, Madagasikara, ), officially the Republic of Madagascar ( mg, Repoblikan'i Madagasikara, links=no, ; french: République de Madagascar), is an island country in the Indian Ocean, approximately off the coast of East Africa ...

. ''Proapteryx'' establishes the existence of flying Australian

palaeognath Palaeognathae (; ) is a infraclass of birds, called paleognaths, within the class Aves of the clade Archosauria. It is one of the two extant infraclasses of birds, the other being Neognathae, both of which form Neornithes. Palaeognathae conta ...

s as recently as the early Miocene, indicating that the

Malagasy Malagasy may refer to: *Someone or something from Madagascar *Malagasy people *Malagasy language *Malagasy Republic *Related to the culture of Madagascar See also *Madagascar (disambiguation) Madagascar is an island country located off the east ...

ratites may have flown across the Indian Ocean around this time.

References

{{Taxonbar, from=Q16757705 Paleognathae Ratites Miocene birds Fossils of New Zealand Birds of the South Island Extinct birds of New Zealand Endemic fauna of New Zealand Fossil taxa described in 2013 Extinct monotypic bird genera Endemic birds of New Zealand