Search results
Discover more placesNear Columbus, OH
Refine results for Animal & Pet Services
Over 1.5 million living animal species have been described, of which around 1.05 million are insects, over 85,000 are molluscs, and around 65,000 are vertebrates. It has been estimated there are as many as 7.77 million animal species on Earth. Animal body lengths range from 8.5 μm (0.00033 in) to 33.6 m (110 ft).
- Overview
- The animal kingdom
- GeneratedCaptionsTabForHeroSec
Animals are multicellular eukaryotes whose cells are bound together by collagen. Animals dominate human conceptions of life on Earth because of their size, diversity, abundance, and mobility. The presence of muscles and mobility is one of the primary characteristics of the animal kingdom.
What are the two major groups of animals?
The two major groups of animals are vertebrates and invertebrates. Vertebrates have backbones, and invertebrates do not.
When did animals first appear?
Animals first appeared in the Ediacaran Period, about 635 million to 541 million years ago, as soft-bodied forms that left traces of their bodies in shallow-water sediments.
What are the basic functional systems of animals?
Animals evolved from unicellular eukaryotes. The presence of a nuclear membrane in eukaryotes permits separation of the two phases of protein synthesis: transcription (copying) of deoxyribonucleic acid (DNA) in the nucleus and translation (decoding) of the message into protein in the cytoplasm. Compared to the structure of the bacterial cell, this ...
Learn about the kingdom Animalia, which includes all multicellular organisms with muscles and mobility. Explore the diversity, evolution, and behaviour of animals with Britannica's experts.
Explore the fascinating world of animals with National Geographic. Read stories, see photos, and learn facts about wildlife, conservation, and evolution.
Welcome to Animalia, an online animal encyclopedia where you can learn about all your favourite animals, and even some you may have never heard of.
Explore the diversity and wonder of animals with pictures, videos, facts, news, and more from National Geographic. Discover the Photo Ark project, the latest animal stories, and the best of National Geographic.
Learn about any animal using the search box or browse by letter. Discover the types, characteristics, habitats, and conservation status of thousands of animals from around the world.
There are many different types of animals. The common animals most people know are only about 3% of the animal kingdom. When biologists look at animals, they find things that certain animals have in common. They use this to group the animals in a biological classification.
