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Les plus anciennes cryptospores sont connues dès le Llanvirn. Les assemblages de ces sporomorphes évolueront peu jusqu'au Llandovery, période au cours de laquelle la plupart des espèces de cryptospores seront remplacées. De manière très caractéristique, les formes entourées d'une membrane vont régresser nettement. Les spores trilètes apparaissent à l'Ashgill et c'est seulement au Wenlock qu'elles...
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