Naasature

The use of the Latin name of two words - the name of the genus, then the specific name - made it possible to separate the nomenclature from the taxonomy. In the original scheme of Carl Linnaeus, animals were assigned to one of three kingdoms, divided into classes Worms, Insects, Fishes, Reptiles (later Amphibians and Reptiles), Birds and Mammals. Since then, the last four classes have been merged into one phylum, the chordates, while the rest of the classes have been classified as invertebrates.

Panarthropoda
Main article: Panarthropoda
Panarthropoda (lat.) is a taxon of invertebrates from the protostomia group (Protostomia), uniting arthropods, tardigrades, onychophora, including the extinct group of xenusia.

The general features of the structure of Panarthropoda are subject to the laws of metameric symmetry: the body of the organism includes several similar elements - segments - located one after another along the axis of the body. One of the most noticeable manifestations of segmentation is the arrangement of paired limbs, which in all Panarthropoda were originally armed with hard claws. Metamerism is also characteristic of internal organs: muscles that set limbs in motion, excretory organs, and elements of the nervous system.Panarthropoda

Spiralia

Grape snail (Helix pomatia)
Main article: Spiral
Spiral (lat. Spiralia) is a huge group of invertebrates, including mollusks and annelids. The former include, in particular, snails, bivalves and squids, while the latter include earthworms and leeches. At the same time, annelids (due to the segmentation of their body) were considered closer to arthropods . The group was proposed in 1995 by Kenneth M. Halanych based on molecular studies. Molecular data, such as the evolution of small rRNA subunits, prove the monophyly of the types of this supertype.

animal groups
protostomes

Yellow-winged Throwing Dragonfly (Sympetrum flaveolum)
Main article: Protostomes
Protostomia (lat. Protostomia) is a taxon of multicellular animals from the Bilateria group. During the period of embryonic development, in place of their primary mouth (blastopore), a mouth is formed or, with a slit-like closure of the blastopore, a mouth and a**s. In this they differ from deuterostomes, in which an a**s is formed in place of the blastopore, and the oral opening appears later in another place.

The classification of the animal kingdom is not well-established and there are many variations. Sometimes protozoa are assigned to animals as a subkingdom on the basis that they are (mostly) heterotrophic actively moving organisms. But on the other hand, protozoa often have the characteristics of plants to no lesser extent and occupy, in a sense, an intermediate position between animals and plants. Therefore, protists are also isolated in a separate kingdom (or several kingdoms). In some classifications, the subkingdom Agnotozoa was distinguished, including placozoans, orthonectids, and dicyemides.