plural noun

: an order of Silurian fossil echinoids having small irregular spheroidal or flattened tests

Word History


New Latin, irregular from Echinocystites, fossil genus of Echinodermata (from echin- + -cystis + -ites -ite) + -oida

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Dictionary Entries Near Echinocystoida

Cite this Entry

“Echinocystoida.” Dictionary, Merriam-Webster, Accessed 18 Apr. 2024.

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