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)
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- Adder
- Aesculapian Snake
- African Clawed Frog
- African Grey Parrot
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- Albacore
- Alcathoe Bat
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- Alpine Newt
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- Alpine Swift
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- American Bull Frog
- American Golden Plover
- American Mink
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- American Wigeon
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- Amur Ratsnake
- Anchovy
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- Angler Fish
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- Aquatic Warbler
- Arctic Char
- Arctic Redpoll
- Arctic Skua
- Arctic Tern
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- Avocet
- Baikal Teal
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- Balearic Shearwater
- Ballan Wrasse
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- Bank Vole
- Bar-headed Goose
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- Barbastelle
- Barbel
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- Barn Owl
- Barnacle Goose
- Barred Warbler
- Baryonyx
- Basking Shark
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- Bearded Tit
- Bechstein's Bat
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- Bee-eater
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- Bewick's Swan
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- Bitterling
- Bittern
- Black Duck
- Black Goby
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- Black Guillemot
- Black Kite
- Black Rat
- Black Redstart
- Black Sea Bream
- Black Swan
- Black Tern
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- Black-headed Gull
- Black-necked Grebe
- Black-tailed Godwit
- Black-throated Diver
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- Blackbird
- Blackcap
- Blackmouth Dogfish
- Blackpoll Warbler
- Bleak
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- Blonde Ray
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- Blue Marlin
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- Blue Tit
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- Blue-winged Teal
- Bluethroat
- Blunt Nose Six Gill Shark
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- Blyth's Reed Warbler
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- Booted Warbler
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- Brambling
- Brandt's Bat
- Brent Goose
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- Brill
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- Broadbill Swordfish
- Bronze Bream
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- Brown Long-eared Bat
- Brown Trout
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- Buff-breasted Sandpiper
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- Bullfinch
- Bullhead
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- Cackling Goose
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- Canada Goose
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- Canvasback
- Capercaillie
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- Carp Family
- Carrion Crow
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- Cattle Egret
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- Cetti's Warbler
- Chaffinch
- Chicken
- Chiffchaff
- Chinese Goose
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- Chinese Water Deer
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- Chough
- Chub
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- Cirl Bunting
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- Coal Tit
- Coalfish
- Cod
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- Collared Dove
- Collared Pratincole
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- Common Blenny
- Common Bottlenose Dolphin
- Common Buzzard
- Common Carp
- Common Cuckoo
- Common Dolphin
- Common Frog
- Common Garter Snake
- Common Goby
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- Common Minke Whale
- Moorhen
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- Common Pipistrelle
- Common Redpoll
- Common Sandpiper
- Common Scoter
- Common Seal
- Common Shrew
- Common Skate
- Common Tern
- Common Toad
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