Animals

Animals are multicellular organisms equipped with nervous systems and the ability to pursue or capture their food. We can be divided into six broad categories :

1, Invertebrates
The first animals to evolve, as far back as a billion years ago, invertebrates are characterized by their lack of backbones and internal skeletons, as well as their relatively simple anatomy and behavior, at least as compared to most vertebrates.

2, Fish 

The first true on earth, fish evolved from invertebrate ancestors about 500 million years ago, and have dominated the world's oceans, lakes, and rivers ever since.

3, Amphibians
When the first amphibians evolved from their tetrapod ancestors, 400 million years ago, they quickly became the dominant vertebrates on earth. Amphibians are characterized by lifestyles that they have to stay near bodies of water, both to maintain the moisture of their skin and to lay their eggs and today they are among the most endangered animals on earth.

4, Reptiles

Reptiles like amphibians, it make up a fairly small proportion of terrestrial animals but in the form of dinosaurs, they ruled the earth for over 150 million years. There are four basic types of reptiles: crocodiles and alligators, turtles and tortoises, snakes, and lizards.

5, Birds

Birds evolved from dinosaurs it's not once, but probably multiple times during the Mesozoic Era, and today they are by far the most prolific flying vertebrates. Birds are characterized by their coats of feathers, their warm-blooded metabolisms, their memorable songs (at least in certain species), and their ability to adapt to a wide range of habitats at ostriches of the Australian plains and the penguins of the Antarctic coastline.

6, Mammals

It's natural for people to consider mammals the pinnacle of evolution. after all, humans are mammals, and so were our ancestors. Mammals are characterized by their hair or fur (which all species possess during some stage of their life cycles). As with birds, They allows themselves to inhabit a wide range of habitats, ranging from deserts to oceans to arctic tundra.