Chordates (phylum Chordata) are animals which are either vertebrates or one of several closely related invertebrates. They are united by having, for at least some period of their life cycle, a notochord, a hollow dorsal nerve cord, pharyngeal slits, an endostyle, and a post-anal tail. The phylum Chordata consists of three subphyla: Urochordata, represented by tunicates; Cephalochordata, represented by lancelets; and Craniata, which includes Vertebrata. The Hemichordata have been presented as a fourth chordate subphylum, but they are now usually treated as a separate phylum. Urochordate larvae have both a notochord and a nerve cord which are lost in adulthood. Cephalochordates have a notochord and a nerve cord (but no brain or specialist sensory organs) and a very simple circulatory system. Craniates are the only sub-phylum whose members have skulls. In all craniates except for hagfish, the dorsal hollow nerve cord is surrounded with cartilaginous or bony vertebrae and the notochord is generally reduced; hence, hagfish are not regarded as vertebrates. The chordates and three sister phyla, the Hemichordata, the Echinodermata and the Xenoturbellida, make up the deuterostomes, one of the two superphyla that encompass all fairly complex animals.
All items (964)
- Coot
- Corkwing Wrasse
- Corn Bunting
- Corn Crake
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- Cory's Shearwater
- Cow
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- Crane
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- Crested Tit
- Crossbill
- Crucian Carp
- Cruxicheiros
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- Cuckoo Wrasse
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- Curlew
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- Edible Dormouse
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- Eel
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- Egyptian Goose
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- Eider
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- Eurasian Badger
- Eurasian Eagle Owl
- Eurasian Shag
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- European Hare
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- European Rabbit
- European Roller
- European Stingray
- European Storm-petrel
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- Exmoor Pony
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- Falcated Duck
- Fallow Deer
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- Feral Goat
- Feral Pigeon
- Ferruginous Duck
- Field Vole
- Fieldfare
- Fin Whale
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- Firecrest
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- Flounder
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- Forster's Tern
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- Frog Spawn
- Frogs
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- Fulmar
- Gadwall
- Gannet
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- Garfish
- Garganey
- Ghost Carp
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- Glossy Ibis
- Goldcrest
- Golden Eagle
- Golden Grey Mullet
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- Golden Pheasant
- Golden Plover
- Goldeneye
- Goldfinch
- Goldfish
- Goldsinny
- Goosander
- Goshawk
- Grass Carp
- Grass Snake
- Grasshopper Warbler
- Grayling
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- Great Cormorant
- Great Crested Grebe
- Great Crested Newt
- Great Grey Shrike
- Great Northern Diver
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- Great Shearwater
- Great Skua
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- Great Spotted Woodpecker
- Great Tit
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- Greater Flamingo
- Greater Horseshoe Bat
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- Greater Spotted Dogfish
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- Green Sandpiper
- Green Sea Turtle
- Green Woodpecker
- Green-winged Teal
- Greenfinch
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- Greenshank
- Grey Gurnard
- Grey Heron
- Grey Long-eared Bat
- Grey Partridge
- Grey Phalarope
- Grey Plover
- Grey Seal
- Grey Squirrel
- Grey Wagtail
- Grey-cheeked Thrush
- Greylag Goose
- Griffon Vulture
- Gudgeon
- Guillemot
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