ammonoids

Noun

ammonoid (plural ammonoids)

1. An extinct cephalopod of the subclass †Ammonoidea (including ammonites).
   • Although the extinct externally shelled cephalopods ammonoids have an extensive fossil record, their soft tissues are very poorly known and, like extinct and living nautiloids, they are largely presumed to not have possessed an ink sac.2017 August 9, Mark Carnall, “Why do cephalopods produce ink? And what's ink made of, anyway?”, in The Guardian

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