Ostriches are the largest living birds, weighing over 200lbs and standing up to nine feet tall. A single ostrich egg is over twenty times larger than a domestic chicken egg. In this skeleton, the greatly reduced wing bones of the ostrich are visible, along with its sternum (breastbone) which lacks the deep keel found in flying birds. Also visible is the unusual foot, which has only two toes (all other living birds have either three or four toes). Ostriches are today found only in Africa, but they once ranged into the Middle East and Asia.