The ostriches are a family of flightless birds. The two extant species of ostrich are the common ostrich and Somali ostrich, both in the genus 'Struthio', which also contains several species known from Holocene fossils such as the Asian ostrich. The common ostrich is the more widespread of the two living species, and is the largest living bird species. Other ostriches are also among the largest bird species ever.

At 5 cm in diameter, the ostrich has the largest eye of any land animal. They are bigger than their brains but this does not make them stupid, however. It is not a case of an undersized brain but rather of oversized eyes.

More Info: www.reference.com