| 释义 |
‖ pro-ostracum Palæont.|prəʊˈɒstrəkəm|
[mod.L., f. Gr. πρό, pro-2 + ὄστρακον potsherd, shell.]
The anterior prolongation, usually lamellar, of the guard or rostrum of a fossil cephalopod, as a belemnite.
1872Nicholson Palæont. xxvi. 297 The form of the ‘pro-ostracum’ varies greatly in different cases, and it affords important characters in the discrimination of specific and generic forms in the Belemnitidæ. 1877Huxley Anat. Inv. Anim. viii. 542 The pro-ostracum and the rostrum together represent the pen in the Teuthidae. 1889Nicholson & Lydekker Palæont. I. 876 A horny or more or less calcified plate, known as the pro-ostracum..corresponds with the ‘pen’ of the ordinary cuttlefishes, and from its extreme tenuity is never perfectly preserved.
Hence pro-ˈostracal a., of, pertaining to, or of the nature of a pro-ostracum.
1890in Cent. Dict. |