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;
Evolution of birds debate. There is significant evidence that birds emerged within theropod dinosaurs, specifically, that birds are members of Maniraptora, a group of theropods which includes dromaeosaurs and oviraptorids, among others. As more non-avian theropods that are closely related to birds are discovered, the formerly clear distinction between non-birds and birds becomes less so. This was noted already in the 19th century, with Thomas Huxley writing: We have had to stretch the definition of the class of birds so as to include birds with teeth and birds with paw-like fore limbs and long tails. There is no evidence that "Compsognathus" possessed feathers;