placoid

shagreen Untanned sharkskin retaining the placoid scales;

鲨鱼皮保留盾鳞的未鞣制鲨鱼皮；

denticle The tooth-like scale of elasmobranchs; placoid scale of cartilaginous fish; also called dermal denticle.

细鳞板鳃类的像牙齿一样鳞片;软骨鱼的盾鳞;也被称为表皮的细鳞。

dentine A hard mesodermal material in teeth and some scales (cosmoid, ganoid and placoid scales) produced by odontobasts.

齿组成牙齿或某些鳞片(硬鳞与盾鳞)中层的坚硬物。

enamel A shiny hard material covering the dentine of teeth and the surface of some scales (cosmoid and placoid scales).

有光泽的坚硬物包覆在牙齿及一些鳞片(圆鳞与盾鳞)表面。这是脊椎动物所产生最坚硬的物。

stomodeal denticles Special placoid scales lining the mouth and pharyngeal cavities of some Elasmobranchii, e.g. Heterodontus.

口道小齿在一些板鳃亚纲的嘴巴与咽洞里的特化盾鳞，例如虎鲨。