proostracum (English, noun)
expansion: proostracum (plural proostraca)
Senses:
topics: biology
history
human-sciences
natural-sciences
paleontology
sciences
glosses: The anterior prolongation of the guard of the phragmocone of belemnites and allied fossil cephalopods, whether horny or calcareous.
Forms:
form: proostraca
tags: plural