规模

的规模,在动物学中，动物皮肤的骨性或角质的外生物。鱼鳞的主要成分是骨头，随着鱼的生长，它们直接在皮肤膜上形成。鳞片的行数，以及种类，是鉴定一个物种的数字。鳞片的生长用环来标记，这有助于确定鱼的年龄。鲨鱼的鳍状鳞片有牙本质基底和牙髓腔，被认为与高等脊椎动物牙齿的进化形式相似。鱼鳞，发现于原始鱼类，如梭鱼和鲟鱼，是沉重的板状。其他鱼类要么有粗糙的鳞片(栉状鳞片)，边缘梳状，要么有光滑的鳞片(摆线鳞片)。大多数爬行动物的角质鳞片或鳞甲，在胚胎时期是表皮的外延。有些蜥蜴的鳞片被修饰成结节或颗粒。其他蜥蜴和蛇有重叠的鳞片，高度发达的蛇作为辅助移动。 The crocodile has both horny and bony scales. Among turtles and their relatives scales are usually found on the head, neck, limbs, and tail; in most of the group horny scales also form a pattern of flat plates overlying the bony dermal skeleton of the back and belly. Birds have horny scales on the feet and sometimes on the legs. Some mammals, e.g., the mouse and the rat, have scales on the tail; the pangolin and the armadillo have a body covering of large horny scales.

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