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Hvirveldyr

Tilbage til: organisme, dyr, rygstrengsdyr.

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Hvirveldyr (Vertebrata) tilh�rer rygstrengsdyrene. Hvirveldyrene har udviklet et akseskelet af brusk, ben eller forbenet brusk kaldet en rygs�jle, der beskytter de tykke nervebaner der ligger i rygstrengen, chordaen.

De fleste hvirveldyr har udviklet to par lemmer samt en hjernekasse.

If�lge Tree of Life web projekt Vertebrata, Animals with backbones ser en delm�ngde af hvirveldyr hierarkiet s�dan ud (2003):

• Hvirveldyr Vertebrata
  • K�bel�se hvirveldyr Agnatha (slim�l, lampret...)
    • Rundmundede fisk Cyclostomata (Se evt. ogs� fisk)
  • K�beb�rende hvirveldyr Gnathostomata
    • Fisk med benpanser Placodermi udd�d
    • Bruskfisk Chondricthyes (Se evt. ogs� fisk)
      • Havmus (Holocephali) Holocephali (havmus, haj, r�dhaj, sildehaj, den hvide haj, s�mrokke, rokke, elrokke, (skade (rokke) raja batis)...)
        • Tv�rmunde Elasmobranchii
    • Benfisk Teleostomi
      • Acanthodii udd�d
      • Osteichthyes
        • Str�lefinnede fisk Actinopterygii (Se evt. ogs� fisk) (torsk, s�hest, hvilling, �l, s�heste...)
        • K�dfinnefisk Sarcopterygii (Se evt. ogs� fisk)
          • Kvastfinnefisk Crossopterygii Coelacanthimorpha
          • Lungefisk Dipnoi
            • Familie Lepidosirenidae Sydamerikanske lungefisk
            • Familie Protopteridae Afrikanske lungefisk
          • Tetrapoder (Krybdyr, Dinosaurer, Pattedyr, Fugle, Padder...)

Eksterne henvisninger

• Fishbase: Danske popul�rnavne (og med latinske)
• 2004-05-07, Sciencedaily: Surprising 'Ultra-conserved' Regions Discovered In Human Genome Citat: "..."As far as we can tell, most of these ultra-conserved elements showed up during the evolution of vertebrates, perhaps during the period when land animals emerged, or a bit earlier. But their early evolutionary history is still mysterious," Haussler said..."
• 2004-05-06, Sciencedaily: Scripps Scientists Look Deep Inside Sharks And Their High-performance Swimming System Citat: "..."Sharks and bony fishes have been separated for over 400 million years and yet we see one group of sharks and one group of bony fish that share a remarkable host of similarities in body form and function," said Donley..."
• BBCNews, 9 May, 2003, Animals 'are moral beings' Citat: "..."But the weight of scientific opinion is that it's certainly right to give the benefit of the doubt to all vertebrates."..."
• Markku Savela: Life (Omfattende).
• Fishbase search ( 27,315 Species, 76,410 Synonyms, 137,515 Common names, 34,720 Pictures, 29,525 References, 930 Collaborators, 6.2 million Hits/month) (3/2003).