| 释义 |
cleithrum Zool.|ˈklaɪθrəm|
Pl. cleithra.
[mod.L. (C. Gegenbaur 1895, in Morphol. Jahrb. XXIII. 1), f. Gr. κλεῖθρον bar for closing a door.]
A dermal bone in the pectoral arch of some fishes and amphibia.
1896Zool. Rec. 1895 Pisces 15 The bone termed clavicula in Fishes is not homologous with that of higher Vertebrates... The two bones are now called clavicula and cleithrum. 1910Encycl. Brit. XIV. 262/2 The primitive pectoral girdle..becomes in the Teleostomes..replaced functionally by a secondary shoulder girdle formed of superficially placed membrane bones (supraclavicular and cleithrum or ‘clavicle’). 1910Parker & Haswell Textbk. Zool. (ed. 2) II. 302 There is also, on each side, a bone called the cleithrum, connected with the corresponding clavicle: there is..reason for thinking this to be homologous with the bone..called clavicle in Teleostomi. 1956A. S. Romer Osteol. Reptiles vii. 298 The cleithrum, however, is an element which tended toward rapid reduction, even in early reptiles. |