Animals are a major group of multicellular, eukaryotic organisms of the kingdom Animalia or Metazoa. Their body plan eventually becomes fixed as they develop, although some undergo a process of metamorphosis later on in their life. Most animals are motile, meaning they can move spontaneously and independently. Animals are also heterotrophs, meaning they must ingest other organisms for sustenance.
Most known animal phyla appeared in the fossil record as marine species during the Cambrian explosion, about 542 million years ago.
Cats (Felidae)Last Updated on 2009-03-21 at 17:54Felidae is the biological family of the cats; a member of this family is called a felid. Felids are the most strictly carnivorous of the sixteen mammal families in the order... More »