A spine of the animal, a sub-door for the chordate. Such animals generally symmetrical shape, the body divided into head, trunk and tail of three parts, the trunk has been the diaphragm into the chest and abdomen, have a better sense organs, exercise a high degree of differentiation of organs and nervous system. Including fish, amphibians, reptiles, birds and mammals and other top-five.
Translated by Google
No. 2
脊椎动物
Effective origin of vertebrates research in paleontology, modern zoological information should be as close as possible to the source of origin of vertebrates hours to explore important clues do two tasks: first, to attempt to identify the most ancient, the most primitive vertebrates, then it is to these vertebrate ancestor as a starting point, forward stepwise retrospective invertebrates Deuterostomia perfect ancestral sequences. China has saved 518 million years ago, many fine after mouth animal soft-bodied fossils of Chengjiang, just close to the "source". Provides a rare opportunity for Chinese scholars to uncover the mystery.
Translated by Google
概念
Reptiles:
Translated by Google
Encyclopedia
Vertebrate Highest animal kingdom and other taxa, consisting of a chordate subphylum - vertebrate subphylum. Symmetrical shape, usually separately, trunk and tail of three parts. Multi-trunk with paired appendages, aquatic animals chest, pelvic, terrestrial animals before, hindlimb. Vivo spinal vertebrae connected together by a number, and have developed skull. Invertebrates contrast, the backside of the central nervous system in the body, the heart in the ventral. Oviparous, ovoviviparous or viviparous. Separable round mouth Gang, Pisces, Amphibia, Reptilia, Aves and Mammalia six classes.
Fish