proostracum
Noun
Meaning
The anterior prolongation of the guard of the phragmocone of belemnites and allied fossil cephalopods, whether horny or calcareous. See Illust. of Phragmocone.
Source: Webster's dictionaryNoun
The anterior prolongation of the guard of the phragmocone of belemnites and allied fossil cephalopods, whether horny or calcareous. See Illust. of Phragmocone.
Source: Webster's dictionary