Animal Kingdom

What is an Animal Kingdom?

Animal classification

What is an Animal Kingdom?

The Animal Kingdom includes eukaryotic multicellular organisms (organism whose cells contain complex structures enclosed within membranes) which exhibit heterotrophic nutrition (nutrition obtained by digesting organic compounds). They are commonly known as animals and differ characteristically from the other major groups of plants, in their capacity to be able to move.

There are many different types of animals in the world. They contribute to about a million living species that occur in all types of habitat and exhibit a great deal of variation in their form, size and life styles. Many are quite similar to each other, others are quite different. Animals can be classified based on their similarities.

Animal classification

Animals are classified into 2 main groups, as follows:

Invertebrates Animals without a Backbone or Spinal Column:	Vertebrates Animals with a Backbone or Spinal Column: (All these animals are in the phyla Chordata and the subphyla Vertebrata.)
Protozoa (phyla: protozoa)	Fish (group: Pisces)
Echinoderms such as starfish (phyla: Echinodermata)	Amphibians such as frogs (class: Amphibia)
Annelids such as earthworms (phyla: Annelida)	Reptiles such as crocodiles (class: Reptilia)
Mollusks such as octopus (phyla: Mollusca)	Birds (class: Aves)
Arthropods such as crabs, spiders and insects (phyla: Arthropoda)	Mammals (class: Mammalia)
Crustaceans such as crabs (subphyla: Crustacea)	Marsupials such as kangaroos (order: Marsupialia)
Arachnids such as spiders (subphyla: Chelicerata class: Arachnida)	Primates such as gorillas and chimpanzees (order: Primates)
Insects (subphyla: Uniramia class: Insecta)	Rodents such as mice (order: Rodentia)
	Cetaceans such as whales and dolphins ( order: Cetacea)
	Animals such as seals (order: Carnivora family: Phocidae)