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.[1]
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.
Cladogram of modern bird relationships based on Jarvis, E.D. et al. (2014)[2] with some clade names after Yuri, T. et al. (2013).[3]
The Palaeognathae or "old jaws" is 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 ratites placed in other orders.[6][7]
Nearly all living birds belong to the subclass Neognathae or "new jaws". With their keeled sternum (breastbone), unlike the ratites, they are known as carinatae.