Bird of prey and may be raised to an order of their own, Cathartiiformes. The secretary bird and/or osprey are sometimes listed as subfamilies of Acciptridae: Sagittariinae and Pandioninae, respectively. Australia's letter-winged kite is a member of the family Accipitridae, although it is a nocturnal bird. The nocturnal birds of prey – the owls – are classified separately as members of two extant families of the order Strigiformes: Below is a simplified phylogeny of Telluraves which is the clade where the birds of prey belong to along with passerines and several near-passerine lineages. The orders in bold text are birds of prey orders;
The Origin of Birds the reptile." He also finds the eyes of birds and reptiles to be remarkably similar, especially the development of the lens, as well as the ear, which reveals a much wider gap between the Sauropsida and mammals than with birds. He describes the sexual organs of birds and reptiles to likewise be structurally similar, and finds that while most species of male bird have lost the penis to reduce weight, those that retain it bear remarkable similarities to extant reptiles. He writes that secondary sexual characteristics are also similar between birds and reptiles, with both groups frequently utilizing bright colors