Proostracum

[pru:st'rækəm]

解释:

(n.) The anterior prolongation of the guard of the phragmocone of belemnites and allied fossil cephalopods, whether horny or calcareous. See Illust. of Phragmocone.

录入:普勒斯顿

解释:

n. the forward continuation of the guard or rostrum in the Belemnites.

录入:内德