proostracum
/pru:st'rækəm/
📖 中文释义
- [医]前甲(箭石)
📘 English Definition(英文释义)
- n. The anterior prolongation of the guard of the
- phragmocone of belemnites and allied fossil cephalopods, whether horny
- or calcareous. See Illust. of Phragmocone.
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/pru:st'rækəm/