Definition of Echinocystoida
:an order of Silurian fossil echinoids having small irregular spheroidal or flattened tests
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Echinocystoida
plural noun
Echi·no·cys·toi·da
\
"+sə̇ˈstȯidə
\
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Origin and Etymology of echinocystoida
New Latin, irregular from Echinocystites, fossil genus of Echinodermata (from echin- + -cystis + -ites -ite) + -oida
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