Order Summary for Polypteriformes
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Main Ref |
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Order |
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Polypteriformes bichirs |
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Class |
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Cladistii |
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Sister Order |
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Acipenseriformes 200 M years |
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Ref. |
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First Fossil Record |
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middle Jurassic |
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Occurs in |
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Marine |
Fresh |
Brackish |
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Remark |
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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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Class etymology |
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Greek aktis = ray, thunderbolt, beam + Greek pterygion, diminutive of pteryx = wing, fin. Ref. 45335. |
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Order etymology |
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Greek, poly = a lot of + Greek, pteron = fin + Latin, forma = shape (Ref. 45335). |
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Families |
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( n = 1 ) Polypteridae |