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Order Summary for Petromyzontiformes
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Main Ref |
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Order |
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Petromyzontiformes lampreys |
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Class |
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Petromyzonti |
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Sister Order |
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Chimaeriformes 455 M years |
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Ref. |
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First Fossil Record |
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late Ordovician |
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Occurs in |
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Marine |
Fresh |
Brackish |
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Remark |
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No bone; seven pairs of external lateral gill openings; eyes lateral (except in Mordacia; tail isocercal in adults, hypocercal in ammocoete larvae; body naked, eel-like; no paired fins. |
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Class etymology |
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Greek, Kephale = head + Greek, aspidos = shield + Greek morphe= shape. Ref. 45335. |
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Order etymology |
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Latin, petra = stone + Greek, myzo = to suckle + Latin, forma = shape (Ref. 45335). |
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Families |
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