proostracum

noun
pro·​os·​tra·​cum | \ prōˈästrə̇kəm \
plural proostraca\ -​kə \

Definition of proostracum

: the anterior horny or calcareous prolongation of the phragmocone of belemnites and related cephalopods

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History and Etymology for proostracum

New Latin, from pro- entry 1 + Greek ostrakon earthen vessel, potsherd, shell

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Cite this Entry

“Proostracum.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/proostracum. Accessed 25 Jul. 2021.

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