Ordning Sammanfattning for Polypteriformes
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Huvudreferens |
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Ordning |
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Polypteriformes bichirs |
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Klass |
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Cladistii |
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Systerordning |
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Acipenseriformes 200 M years |
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Ref. |
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Äldsta kända fossil |
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middle Jurassic |
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Förekommer i |
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Marina |
Sötvatten |
Brackvatten |
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Kommentar |
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Rhombic ganoid scales; spiracular, opening large but canal lost; dorsal fin consisting of 5-18 finlets, each with a single spine to which is attached one or more soft rays; pectoral fin rays supported by numerous ossified radials which attach to a cartilaginous plate and two rods, thence to the scapula and coracoid; a pair of gular plates, no branchiostegals; maxilla firmly united to skull; intestine with spiral valve; lungs partially used in respiration; vertebrae with ossified centra and neural canal. Maximum length about 90 cm, most species less than 30 cm. |
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Klass Etymologi |
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Greek aktis = ray, thunderbolt, beam + Greek pterygion, diminutive of pteryx = wing, fin. Ref. 45335. |
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Ordning Etymologi |
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Greek, poly = a lot of + Greek, pteron = fin + Latin, forma = shape (Ref. 45335). |
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Familjer |
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( n = 1 ) - Polypteridae |
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