Struthio

Struthio Temporal range: Miocene-Holocene, 23–0 Ma PreЄ Є O S D C P T J K Pg N
Common ostrich (Struthio camelus), male and female
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Aves
Order:	Struthioniformes
Family:	Struthionidae
Genus:	Struthio Linnaeus, 1758
Type species
Struthio camelus Linnaeus, 1758
Species
†Struthio coppensi †Struthio linxiaensis †Struthio orlovi †Struthio wimani †Struthio brachydactylus †Struthio asiaticus Asian ostrich †Struthio dmanisensis †Struthio oldawayi Struthio molybdophanes Somali ostrich Struthio camelus Common ostrich

Struthio is a genus of bird in the order Struthioniformes.

Species

There are ten known species from this genus, of which eight are extinct. There are five more possible species of which trace fossils have been found. They are:

• †Struthio coppensi (Early Miocene of Elizabethfeld, Namibia)
• †Struthio linxiaensis (Liushu Late Miocene of Yangwapuzijifang, China)
• †Struthio orlovi (Late Miocene of Moldavia)
• †Struthio karingarabensis (Late Miocene - Early Pliocene of SW and CE Africa) - oospecies(?)
• †Struthio kakesiensis (Laetolil Early Pliocene of Laetoli, Tanzania) - oospecies
• †Struthio wimani (Early Pliocene of China and Mongolia)
• †Struthio daberasensis (Early - Middle Pliocene of Namibia) - oospecies
• †Struthio brachydactylus (Pliocene of Ukraine)
• †Struthio chersonensis (Pliocene of SE Europe to WC Asia) - oospecies
• †Struthio asiaticus, Asian ostrich (Early Pliocene - Late Pleistocene of Central Asia to China ?and Morocco)
• †Struthio dmanisensis, giant ostrich (Late Pliocene/Early Pleistocene of Dmanisi, Georgia)
• †Struthio oldawayi (Early Pleistocene of Tanzania) - probably subspecies of S. camelus
• †Struthio anderssoni - in N China/Mongolia oospecies(?)
• Struthio camelus, common ostrich
• Struthio molybdophanes, Somali ostrich

Fossil records and egg shell fragments show that the ancestors of this genus originated about 40-58 million years ago (mya) in the Asiatic steppes as small flightless birds. The earliest fossils from this genus are from the early Miocene (20-25mya), and are from Africa, so it is proposed that they originated there. Then by the middle to late Miocene (5-13mya) they had spread to Eurasia. By about 12 mya they had evolved into the larger size of which we are familiar. By this time they had spread to Mongolia and, later, South Africa.

Evolution

The genus Struthio used to include the Emu, Rhea, and also the Cassowary, until they each were placed in their own genera. The Somali ostrich, Struthio molybdophanes, has recently become recognized as a separate species by some authorities, while others are still reviewing the information.

References

• Gray, G.R. (1855)
• 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.
• Hou, L. et al. (2005)
• Davies, S.J.J.F. (2003)
• Gil, F. & Donsker D. (2012)
• Birdlife International (2012)