Animales

Animal
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"Animalia" redirects here. For other uses, see Animalia (disambiguation).
For other uses, see Animal (disambiguation).
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Animals
Temporal range: Ediacaran - Recent
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Scientific classification
Domain: Eukaryota
(unranked) Opisthokonta
(unranked) Holozoa
(unranked) Filozoa
Kingdom:Animalia
Linnaeus, 1758
Phyla

Subkingdom Parazoa
Porifera
Placozoa
Subkingdom Eumetazoa
Radiata (unranked)
Ctenophora
Cnidaria
Bilateria (unranked)
Orthonectida
Rhombozoa
Acoelomorpha
Chaetognatha
Superphylum Deuterostomia
ChordataHemichordata
Echinodermata
Xenoturbellida
Vetulicolia †
Protostomia (unranked)
Superphylum Ecdysozoa
Kinorhyncha
Loricifera
Priapulida
Nematoda
Nematomorpha
LobopodiaOnychophora
Tardigrada
Arthropoda
Superphylum Platyzoa
Platyhelminthes
Gastrotricha
Rotifera
Acanthocephala
Gnathostomulida
Micrognathozoa
Cycliophora
SuperphylumLophotrochozoa
Sipuncula
Hyolitha †
Nemertea
Phoronida
Bryozoa
Entoprocta
Brachiopoda
Mollusca
Annelida
Echiura

Animals are a major group of multicellular, eukaryotic organisms of the kingdomAnimalia 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. All animals are also heterotrophs, meaning they must ingest other organisms or their products for sustenance.

Most known animal phyla appeared in the fossil record asmarine species during the Cambrian explosion, about 542 million years ago.
Contents
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1 Etymology
2 Characteristics
2.1 Structure
2.2 Reproduction and development
2.3 Food and energy sourcing
3 Origin and fossil record
4 Groups of animals
4.1 Porifera, Radiata and basal Bilateria
4.2 Deuterostomes
4.3 Ecdysozoa4.4 Platyzoa
4.5 Lophotrochozoa
5 Model organisms
6 History of classification
7 See also
8 References
8.1 Bibliography
9 External links

Etymology

The word "animal" comes from the Latin word animalis, meaning "having breath".[1] In everyday colloquial usage, the word usually refers to non-human animals.[2] Sometimes, only closer relativesof humans such as mammals and other vertebrates are meant in colloquial use.[3] The biological definition of the word refers to all members of the kingdom Animalia, encompassing creatures as diverse as sponges, jellyfish, insects and humans.[4]
Characteristics

Animals have several characteristics that set them apart from other living things. Animals are eukaryotic and mostly multicellular,[5]which separates them from bacteria and most protists. They are heterotrophic,[6] generally digesting food in an internal chamber, which separates them from plants and algae.[7] They are also distinguished from plants, algae, and fungi by lacking rigid cell walls.[8] All animals are motile,[9] if only at certain life stages. In most animals, embryos pass through a blastula stage,[10] which is a...