aptychus

noun ap·ty·chus \ˈaptə̇kəs\

Definition of aptychus

plural

aptychi

\-ˌkī\
  1. :  a shelly plate usually of two pieces found in ammonites and regarded as an operculum

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Origin and Etymology of aptychus

New Latin, from 2a- + Greek ptychē fold — more at ptych-


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to cast off or become cast off

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