Zoology classifies animals with the same or similar characteristics into the same category according to their morphology, internal structure, embryonic development characteristics, physiological habits and geographical environment.
Mainly divided into two categories: chordates and invertebrates; According to aquatic or terrestrial animals, it can be divided into aquatic animals and terrestrial animals; According to whether there are feathers, it can be divided into feathered animals and featherless animals; According to whether there is a spine in the body, we can divide all animals into vertebrates and invertebrates.
Extended data
Some different classes have been upgraded to phyla, such as rotifer, abdominal hair, linear, nematode and other animals in the original prosthesis cavity, and some scholars have upgraded them to phyla.
In addition, some new taxa have been found, which are not suitable for the original phylum, but are newly established as a separate phylum, such as Ctenomedusae, which is because of the discovery of Ctenomedusae.
For the study of medicinal animals, pharmacology 1960 was divided into 10 in the early stage, and later Chinese medicine identification was adopted 1977. The animal kingdom is still divided into 10.
The characteristics are still: cell differentiation, the formation of germ layer, the presence or absence of body cavity, the division of body segments, the nature of bones, the characteristics of appendages, the occurrence and development of other organ systems, and the strata are divided with reference to geological data.
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