Ostriches are large
flightless birds of the
genus ''Struthio'' in the
order
Order, ORDER or Orders may refer to:
* Categorization, the process in which ideas and objects are recognized, differentiated, and understood
* Heterarchy, a system of organization wherein the elements have the potential to be ranked a number of ...
Struthioniformes
Struthioniformes is an order of birds with only a single extant family, Struthionidae, containing the ostriches. Several other extinct families are known, spanning across the Northern Hemisphere, from the Early Eocene to the early Pliocene, includ ...
, part of the infra-class
Palaeognathae
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 cont ...
, a diverse group of flightless birds also known as
ratite
A ratite () is any of a diverse group of flightless, large, long-necked, and long-legged birds of the infraclass Palaeognathae. Kiwi, the exception, are much smaller and shorter-legged and are the only nocturnal extant ratites.
The systematics o ...
s that includes the
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 em ...
s,
rheas, and
kiwis. There are two living species of ostrich: the
common ostrich
The common ostrich (''Struthio camelus''), or simply ostrich, is a species of flightless bird native to certain large areas of Africa and is the largest living bird species. It is one of two extant species of ostriches, the only living members ...
, native to large areas of
sub-Saharan Africa and the
Somali ostrich, native to the
Horn of Africa. The common ostrich was also historically native to the
Arabian Peninsula
The Arabian Peninsula, (; ar, شِبْهُ الْجَزِيرَةِ الْعَرَبِيَّة, , "Arabian Peninsula" or , , "Island of the Arabs") or Arabia, is a peninsula of Western Asia, situated northeast of Africa on the Arabian Plate. ...
, and ostriches were present across Asia as far east as Mongolia during the
Late Pleistocene and possibly into the
Holocene. They lay the largest eggs of any living land animal. With the ability to run at 70 km/h (43.5 mph), they are the fastest birds on land. They are farmed worldwide, particularly for their feathers as they are used as decoration and feather dusters. Their skin is also used for leather products. They are the heaviest living birds.
Taxonomic history
The genus ''Struthio'' was first described by
Carl Linnaeus in 1758. The genus was used by Linnaeus and other early taxonomists to include the
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 em ...
,
rhea, and
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 forest ...
, until they each were placed in their own genera.
[ The Somali ostrich (''Struthio molybdophanes'') has recently become recognized as a separate species by most authorities, while others are still reviewing the evidence.][Birdlife International (2012)]
Evolution
Struthionidae
Struthionidae (; ) is a family of flightless birds, containing the extant ostriches and their extinct relatives. The two extant species of ostrich are the common ostrich and Somali ostrich, both in the genus ''Struthio'', which also contains s ...
is a member of the Struthioniformes
Struthioniformes is an order of birds with only a single extant family, Struthionidae, containing the ostriches. Several other extinct families are known, spanning across the Northern Hemisphere, from the Early Eocene to the early Pliocene, includ ...
, a group of paleognath
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 ...
birds which first appeared during the Early Eocene, and includes a variety of flightless forms which were present across the Northern Hemisphere (Europe, Asia and North America) during the Eocene epoch. The closest relatives of Struthionidae within the Struthioniformes are the Ergilornithidae, known from the late Eocene to early Pliocene of Asia. It is therefore most likely that Struthionidae originated in Asia.
The earliest fossils of the genus ''Struthio'' are from the early Miocene ~21 million years ago of Namibia in Africa, so it is proposed that genus is of African origin. By the middle to late Miocene (5–13 mya) they had spread to and become widespread across Eurasia. While the relationship of the African fossil species is comparatively straightforward, many Asian species of ostrich have been described from fragmentary remains, and their interrelationships and how they relate to the African ostriches are confusing. In India, Mongolia and China, ostriches are known to have become extinct only around, or even after, the end of the last ice age; images of ostriches have been found prehistoric Chinese pottery and petroglyph
A petroglyph is an image created by removing part of a rock surface by incising, picking, carving, or abrading, as a form of rock art. Outside North America, scholars often use terms such as "carving", "engraving", or other description ...
s.[
File: Struthio camelus MHNT.ZOO.2010.11.1.1.jpg, ''Struthio camelus'' egg – MHNT
File:Ostrich & chicken egg comparison.jpg, Size comparison (with a chicken egg and a US dollar bill)
File:Ostrich with eggs.jpg, Ostrich with eggs
]
Distribution and habitat
Today, ostriches are only found natively in the wild in Africa
Africa is the world's second-largest and second-most populous continent, after Asia in both cases. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 6% of Earth's total surface area ...
, where they occur in a range of open arid and semi-arid habitats such as savanna
A savanna or savannah is a mixed woodland-grassland (i.e. grassy woodland) ecosystem characterised by the trees being sufficiently widely spaced so that the canopy does not close. The open canopy allows sufficient light to reach the ground to ...
s and the Sahel, both north and south of the equatorial forest zone. The Somali ostrich occurs in the Horn of Africa, having evolved isolated from the common ostrich by the geographic barrier of the East African Rift. In some areas, the common ostrich's Masai subspecies occurs alongside the Somali ostrich, but they are kept from interbreeding by behavioral and ecological differences. The Arabian ostrich
The Arabian ostrich (''Struthio camelus syriacus''), Syrian ostrich, or Middle Eastern ostrich is an extinct subspecies of the ostrich that lived on the Arabian Peninsula and in the Near East until the mid-20th century.
Distribution
Its range s ...
es in Asia Minor
Anatolia, tr, Anadolu Yarımadası), and the Anatolian plateau, also known as Asia Minor, is a large peninsula in Western Asia and the westernmost protrusion of the Asian continent. It constitutes the major part of modern-day Turkey. The re ...
and Arabia
The Arabian Peninsula, (; ar, شِبْهُ الْجَزِيرَةِ الْعَرَبِيَّة, , "Arabian Peninsula" or , , "Island of the Arabs") or Arabia, is a peninsula of Western Asia, situated northeast of Africa on the Arabian Plat ...
were hunted to extinction by the middle of the 20th century, and in Israel attempts to introduce North African ostrich
The North African ostrich, red-necked ostrich, or Barbary ostrich (''Struthio camelus camelus'') is the nominate subspecies of the common ostrich from West and North Africa. It is the largest subspecies, making it the largest living bird.
Evol ...
es to fill their ecological role have failed. Escaped common ostriches in Australia have established feral
A feral () animal or plant is one that lives in the wild but is descended from domesticated individuals. As with an introduced species, the introduction of feral animals or plants to non-native regions may disrupt ecosystems and has, in some ...
populations.
Species
In 2008, ''S. linxiaensis'' was transferred to the genus '' Orientornis.'' Three additional species, ''S. pannonicus'', ''S. dmanisensis'', and ''S. transcaucasicus'', were transferred to the genus '' Pachystruthio'' in 2019. Several additional fossil forms are ichnotaxa (that is, classified according to the organism's trace fossils such as footprints rather than its body) and their association with those described from distinctive bones is contentious and in need of revision pending more good material.
The species are:
*Prehistoric
** †'' Struthio barbarus'' Arambourg 1979
** †'' Struthio brachydactylus'' Burchak-Abramovich 1939 (Pliocene of Ukraine)
** †''Struthio chersonensis
Ostriches are large flightless birds of the genus ''Struthio'' in the order Struthioniformes, part of the infra-class Palaeognathae, a diverse group of flightless birds also known as ratites that includes the emus, rheas, and kiwis. There are ...
'' (Brandt 1873) Lambrecht 1921 (Pliocene of SE Europe to WC Asia) – oospecies
** †''Struthio coppensi
''Struthio coppensi'' is an extinct species of ostrich located near Elisabethfeld, Namibia. This ostrich is believed to have lived during the Miocene, about 20 mya, and is the oldest member of the ''Struthio'' genus
Genus ( plural genera ) i ...
'' Mourer-Chauviré et al. 1996 (Early Miocene of Elizabethfeld, Namibia)
** †'' Struthio daberasensis'' Pickford, Senut & Dauphin 1995 (Early – Middle Pliocene of Namibia) – oospecies
** †'' Struthio epoasticus'' Bonaparte 1856
** †''Struthio kakesiensis
''Struthio kakesiensis'' is an extinct oospecies of ratite bird known from eggshell fossils found in Laetoli, Tanzania. It was related to the modern day ''Struthio
Ostriches are large flightless birds of the genus ''Struthio'' in the order ...
'' Harrison & Msuya 2005 (Early Pliocene of Laetoli, Tanzania) – oospecies
** †'' Struthio karingarabensis'' Senut, Dauphin & Pickford 1998 (Late Miocene – Early Pliocene of SW and CE Africa) – oospecies
Egg fossils are the fossilized remains of eggs laid by ancient animals. As evidence of the physiological processes of an animal, egg fossils are considered a type of trace fossil. Under rare circumstances a fossil egg may preserve the remains of t ...
(?)
** †'' Struthio oldawayi'' Lowe 1933 (Late Pleistocene of Tanzania) – probably subspecies of ''S. camelus''
** †''Struthio orlovi
''Struthio orlovi'' is an extinct species of ratite bird from the Miocene of Moldavia
Moldavia ( ro, Moldova, or , literally "The Country of Moldavia"; in Romanian Cyrillic: or ; chu, Землѧ Молдавскаѧ; el, Ἡγεμον� ...
'' Kuročkin & Lungo 1970 (Late Miocene of Moldavia)
** †''Struthio wimani
''Struthio wimani'' is an extinct species of ratite bird from the Pliocene of China
China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's List of countries and dependencies by population, mo ...
'' Lowe 1931 (Early Pliocene of China and Mongolia)
* Late Pleistocene Holocene
** †'' Struthio anderssoni'' Lowe 1931, East Asian ostrich (Late Pleistocene of China to Mongolia)[J. G. Andersson, Essays on the cenozoic of northern China. ''Memoirs of the Geological Survey of China (Peking)'', Series A, No. 3 (1923), pp. 1–152, especially pp. 53–77: "On the occurrence of fossil remains of Struthionidae in China."; and J. G. Andersson, Research into the prehistory of the Chinese. Bulletin of the Museum of Far Eastern Antiquities 15 (1943), 1–300, plus 200 plates.] oospecies(?)
** †''Struthio asiaticus
The Asian or Asiatic ostrich (''Struthio asiaticus''), is an extinct species of ostrich that lived during the Neogene period on the Indian subcontinent. The early records that ranged from the Pliocene epoch in Africa to Pleistocene- Holocene epoc ...
'' Brodkorb 1863, Asian ostrich
The Asian or Asiatic ostrich (''Struthio asiaticus''), is an extinct species of ostrich that lived during the Neogene period on the Indian subcontinent. The early records that ranged from the Pliocene epoch in Africa to Pleistocene- Holocene epoc ...
(Early Pliocene – Early Holocene of Central Asia to China? and Morocco)
** '' Struthio camelus'', common ostrich
The common ostrich (''Struthio camelus''), or simply ostrich, is a species of flightless bird native to certain large areas of Africa and is the largest living bird species. It is one of two extant species of ostriches, the only living members ...
*** ''Struthio camelus camelus
The North African ostrich, red-necked ostrich, or Barbary ostrich (''Struthio camelus camelus'') is the nominate subspecies of the common ostrich from West and North Africa. It is the largest subspecies, making it the largest living bird.
Evol ...
'', North African ostrich
The North African ostrich, red-necked ostrich, or Barbary ostrich (''Struthio camelus camelus'') is the nominate subspecies of the common ostrich from West and North Africa. It is the largest subspecies, making it the largest living bird.
Evol ...
*** '' Struthio camelus massaicus'', Masai ostrich
The Masai ostrich (''Struthio camelus massaicus''), also known as the East African ostrich is a red-necked subspecies variety of the common ostrich and is endemic to East Africa. It is one of the largest birds in the world, second only to its sis ...
*** '' Struthio camelus australis'', South African ostrich
The South African ostrich (''Struthio camelus australis''), also known as the black-necked ostrich, Cape ostrich or southern ostrich is a subspecies of the common ostrich endemic to Southern Africa. It is widely farmed for its meat, eggs and feat ...
*** †'' Struthio camelus syriacus'', Arabian ostrich
The Arabian ostrich (''Struthio camelus syriacus''), Syrian ostrich, or Middle Eastern ostrich is an extinct subspecies of the ostrich that lived on the Arabian Peninsula and in the Near East until the mid-20th century.
Distribution
Its range s ...
** '' Struthio molybdophanes'', Somali ostrich
Citations
General references
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{{Authority control
Extant Miocene first appearances
Flightless birds
Miocene birds
Ratites
Taxa named by Carl Linnaeus