Horse
The horse adapted to survive in areas of wide-open terrain with sparse vegetation, surviving in an ecosystem where other large grazing animals, especially ruminants, could not. Horses and other equids are odd-toed ungulates of the order Perissodactyla, a group of mammals that was dominant during the Tertiary period. In the past, this order contained 14 families, but only three—Equidae (the horse and related species), Tapiridae (the tapir), and Rhinocerotidae (the rhinoceroses)—have survived to the present day.
Accipitridae
Many well-known birds, such as hawks, eagles, kites, harriers and Old World vultures are included in this group. The osprey is usually placed in a separate family (Pandionidae), as is the secretary bird (Sagittariidae), and the New World vultures are also usually now regarded as a separate family or order. Karyotype data indicate the accipitrids analysed are indeed a distinct monophyletic group, but whether this group should be considered a family or one or several order(s) on their own is a question still to be resolved.