This article lists living orders and families of birds. The links below should then lead to family accounts and hence to individual species. The passerines (perching birds) alone account for well over 5,000 species. In total there are about 10,000 species of birds described worldwide, though one estimate of the real number places it at almost twice that. Taxonomy is very fluid in the age of DNA analysis, so comments are made where appropriate, and all numbers are approximate. In particular see Sibley-Ahlquist taxonomy for a very different classification. Phylogeny Cladogram of modern bird relationships based on Jarvis, E.D. et al. (2014) with some clade names after Yuri, T. et al. (2013). Paleognathae The Paleognathae, or "old jaws", are one of the two superorders recognized within the taxonomic class Aves and consist of the ratites and tinamous. The ratites are mostly large and long-legged, flightless birds, lacking a keeled sternum. Traditionally, all the ratites were place in the order Struthioniformes. However, recent genetic analysis has found that the group is not monophyletic, as it is paraphyletic with respect to the tinamous, so the ostriches are classified as the only members of the order Struthioniformes and other rattites placed in other orders. Struthioniformes Africa; 2 species Struthionidae: ostrich Notopalaeognathae Rheiformes South America; 2 species †Opisthodactylidae Rheidae: rheas Casuariiformes Australasia; 4 species Casuariidae: cassowaries and emu Apterygiformes Australasia; 5 species Apterygidae: kiwis Aepyornithiformes Madagascar †Aepyornithidae: elephant birds Dinornithiformes New Zealand †Megalapteryidae: upland moas †Dinornithidae: great moas †Emeidae: lesser moas Tinamiformes South America; 45 species Tinamidae: tinamous Neognathae Nearly all living birds belong to the superorder Neognathae or "new jaws". With their keeled sternum (breastbone), unlike the ratites, they are known as carinatae. Galloanserae Galliformes Worldwide; 250 species †Sylviornithidae Megapodii Megapodidae: megapodes Craci Cracidae: chachalacas, curassows, and guans Phasiani Numidioidea Numididae: guineafowl Phasianoidea: pheasants and allies Odontophoridae: New World quail Phasianidae: pheasants and relatives Gastornithiformes †Gastornithidae †Dromornithidae: mihirungs Anseriformes Worldwide; 150 species Anhimidae: screamers Anseranatidae: magpie-goose Anatidae: ducks, geese, and swans Mirandornithes Podicipediformes Worldwide; 19 species Podicipedidae: grebes Phoenicopteriformes Worldwide; 6 species †Palaelodidae: swimming flamingos Phoenicopteridae: flamingos Columbimorphae Columbiformes Worldwide; 300 species Columbidae: pigeons and doves Pterocliformes Africa, Europe, Asia; 16 species Pteroclidae: sandgrouse Mesitornithiformes Madagascar; 3 species Mesitornithidae: mesites Cypselomorphae Caprimulgiformes Worldwide; 97 species Caprimulgidae: nightjars Steatornithiformes South America; 1 species Steatornithidae: oilbird Nyctibiiformes Americas; 7 species Nyctibiidae: potoos Podargiformes Asia and Australasia; 14 species Podargidae: frogmouths Aegotheliformes Australasia; 10 species Aegothelidae: