Taxonomy of birds

• Identification, description and designation of new species of birds, both living and fossil;
• Identification of causes and factors of speciation

The first attempt to systematize animals in the IV century BC. e. undertaken by the Greek scientist Aristotle - in his writings " On the Parts of Animals " and "On the Origin of Animals," he singled out all the birds he knew in the "higher" genus Ornithes ^{[1] [2]} . Despite the obvious imperfection of this system, until the second half of the 17th century, new attempts to classify the animal world were not made. In 1676, the manuscript Ornithologiae libri tres , written by the English biologist Francis Willoughby, was published and, after his death, was prepared and published by his friend and scientist John Ray ^{[3] [4]} . This is the first known work in which the authors attempted to classify birds on the basis of external, morphological characters. Later, in 1758, the Swedish naturalist Karl Linney actively used this work to create his own System of Nature , in which he introduced hierarchical categories and binomial nomenclature to designate species that have been used up to now ^[5] .

In the Linnaeus system, all animals were divided into six main categories - classes , one of which, along with mammals, amphibians, fish, worms and insects, was occupied by birds, or Aves (later categories of a higher order appeared). An alternative phylogenetic taxonomy considers the Aves group as a clade of theropod dinosaurs ^[6] . According to the theory of the origin of birds from ancient dinosaurs, Aves and her sister clade Crocodilia (crocodiles) are considered the only modern branches of the clan reptile Archosauria (archosaurs). All modern birds have a single ancestor, which some scientists consider Archaeopteryx ( Archaeopteryx lithographica ) - the animal that inhabited the Earth at the end of the Jurassic period 150-155 million years ago, which is considered the oldest known bird on the planet ^[7] . Other scientists believe that Archeopteryx was not the ancestor of modern (fan-tailed) birds. A number of well-known dinosaurologists and followers of the FiloCode system, such as Jacques Gauthier , Luis Chiappi and their followers, under the category Aves mean only modern birds, not including groups known only from fossil remains - archaeopteryx, enantiornis , confuciusornis , patagopteryx and some others. However, these scientists introduced a new category of Avialae , or birds in a broad sense, which unites the species living in our time and their fossil precursors ^[8] .

All modern groups of birds belong to the infraclass Neornithes , or fan-tailed birds, which in turn is divided into two categories - Paleognathae , or ratites (this usually includes flightless birds such as ostriches ), and Neognathae , new-born birds (including all other species ) Typically, these two categories have the rank of superorder , although Laivesi and Zusi consider them as cohorts ^[6] . Depending on the classification system, there are from 9800 ^[9] to 10 050 ^[10] modern bird species.

• Real birds

• Kartashev N. N. Systematics of birds: Textbook. allowance for students. high boots and ped. in-tov / Artist: V. M. Smirin , Yu. M. Smirin . - M .: Higher school , 1974. - 368 p. - 20,000 copies.