Ammonoidea

plural noun

Am·​mo·​noi·​dea
ˌaməˈnȯidēə
: an order of extinct chiefly Mesozoic Tetrabranchia comprising cephalopods having an external chambered shell that is either straight or variously curved or coiled see ammonite entry 1
ammonoidean
¦amə¦nȯidēən
adjective or noun

Word History

Etymology

New Latin, irregular from Ammonites + -oidea

First Known Use

1884, in the meaning defined above

Time Traveler
The first known use of Ammonoidea was in 1884

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Dictionary Entries Near Ammonoidea

Cite this Entry

“Ammonoidea.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/Ammonoidea. Accessed 29 Mar. 2024.

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