Vertebrate Zoology - V. M. Konstantinov 2011

Chordates
Terrestrial, or Tetrapod, Vertebrates — Vertebrates with Amniotic Membranes
Class Birds — Subclass Fan-tailed Birds, or True Birds

In this textbook, the Classification basis of the Class Aves follows the latest version of A. Wetmore's system (A. Wetmore, 1960), which was widely adopted and accepted worldwide in the 1990s, recognizing 28 to 30 orders of modern birds. However, since the late 20th century, systematics based on DNA similarity analysis has been rapidly developing. Since 1990, this "molecular" Classification of Birds, developed by Ch. Sibley and co-authors (Ch. Sibley et al., 1990), has gained widespread recognition. These two systems currently coexist in parallel, largely independent of one another.

According to current estimates, the actual number of modern species on the planet is approximately 10,000 (rather than 8,500 as recently believed), with 30 orders and 2,500 to 3,000 families and genera (E.A. Koblik, 2001).



Last update: 13/08/2026

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