There are very few that are completely terrestrial, whales, crocodiles, larvae...I think you can understand

Hexapod: /pic/35/11527565828625047.jpg< /p>

The class Diplopoda includes 2 subclasses, 2 general orders and 7 orders:

The body length of the class Tetragnatha is only a few millimeters, the body wall is soft, does not contain calcium, and the whole body has various The shape of the bristles makes it commonly known as the hairy millipede. The whole body consists of a head and 11 to 13 body segments, with 13 to 17 pairs of legs. There are tufts of brushes at the end of the body. There is only 1 order of Eumata.

Labiognathia has a hard body wall containing calcium. Males have specialized reproductive limbs for walking legs. Bottom points:

① Metamale, the reproductive limbs are located at the end of the body and only play a supporting role when mating with the female. Including: Paramachophora and Phytophthora.

②Anterior male order, the reproductive limb is located on the 7th body segment. Including: Gyprima, Beliala, Gyma, and Hematochondria.

The class Chemipodia is divided into 2 subclasses and 4 orders: 1. Orthopedic subclass. It is divided into the order Centipede and the order Centipede. ② Modified subclass. It is divided into the order Litholopidae and the order Centipede.

The Comprehensive Class includes 3 families: Scolopendrellidae, which has 17 dorsal plates and is a small and slender species. Scuti-gerellidae has 15 dorsal plates and is a relatively stout species. Among them, the genus Hansi has been discovered in China. Geophilelli-dae has 21 to 24 dorsal plates. Only the genus Geophilel-la is included, and species of this genus have been found in northern China.