Cystoidea
| Cystoidea Temporal range: | |
|---|---|
| "Cystoidea" from Ernst Haeckel's Kunstformen der Natur, 1904 | |
| Scientific classification | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Echinodermata |
| Subphylum: | †Blastozoa |
| Informal group: | †Cystoidea von Buch 1846 |
| Subdivisions | |
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Cystoidea was defined as a class of extinct paleozoic blastozoan echinoderms established to encompass stalked taxa that were neither crinoids nor blastoids. It was shown to be polyphyletic in the late 1960s but continues to be used even in recent (as of 2022) literature to discuss both rhombiferans and diploporitans.