Vertebrates have mastered all habitats and are distributed throughout the globe. They lead an active lifestyle, sometimes making distant migrations. Many vertebrate species reach high numbers.
Vertebrates are distinguished by a higher level of development than cranials.
Their body is supported by the spine, which in adult animals replaces the notochord. The skull has developed to protect the brain.
Paired limbs are formed: in fish, paired fins, in terrestrial vertebrates, five-fingered limbs.
The skull and spine protect the brain and spinal cord, which is formed from the neural tube of the noncranial.
The brain consists of five sections: the anterior, middle, medulla oblongata, diencephalon and cerebellum. The formation of numerous conditioned reflexes and the complexity of behavior are associated with the forebrain.
Vertebrates have well-developed sense organs. They have eyes with a focusing lens – a crystalline lens, perfect organs of hearing (most of them have auditory ossicles and membranes that amplify sound waves), taste, smell and touch.
The circulatory system of vertebrates, like all chordates, is closed. Unlike noncranial vertebrates, a muscular heart appears in the circulatory system.
The organs of excretion are the kidneys.
Vertebrates are usually dioecious animals. Females have ovaries and males have testes. Females lay eggs or give birth to fully developed cubs. Many of them tend to instinctively care for their offspring.