What is the traditional classification system of birds?

Compared with bird DNA classification system, the traditional bird classification system is a widely used classification system.

This system is mainly based on the classification system of J. L. Peter, which integrates the research results of morphology, biogeography, ecology, behavior, embryology and paleontology, and has been widely used all over the world.

Taxonomically, birds belong to the ornithoptera of the animal kingdom-Chordata-Vertebrates. All the existing birds belong to the current suborder ornithopoda, with more than 9000 species in 3 orders.

Related introduction:

Traditionally, birds are divided into two subclasses: archaeopteryx and modern birds. All existing birds can be classified into three suborders of modern bird fauna: Archaeoptera, Wedgewing and Modern Archaeoptera. All the existing birds in China belong to modern archaeoptera. Archaeopteryx includes Archaeopteryx. Today, in addition to the three extant suborders, Archaeopteryx also includes the extinct Cladoptera.

Birds are not easy to form fossils, so the fossils of prehistoric birds are very rare and precious, which also makes people have many questions and debates about the origin and early evolution of birds. Although there are not many fossils left by birds, there are many existing species, and the class of birds is the latest and largest class of terrestrial vertebrates. There are nearly 9000 species of birds, almost twice as many as mammals. Although there are many kinds of birds, the differences between different birds are far less than those of mammals.

The difference between members of a mammal order (such as marsupials) may be greater than that between members of two completely different birds. The difference between blue whales, bats and platypus does not exist among birds. The existing birds can be divided into 27~30 orders, 160 families.