Shark teeth as edged weapons: serrated teeth of three species of selachians.
Shark teeth as edged weapons: serrated teeth of three species of selachians.
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作为利器的鲨鱼牙齿：三种鲨鱼的锯齿状牙齿。
DOI：
10.1016/j.zool.2016.05.007
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发表时间：
2017
期刊：
影响因子：
--
通讯作者：
Bemis,WilliamE
中科院分区：
文献类型：
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作者：
Moyer,JoshuaK;Bemis,WilliamE
在欧洲接触之前，南太平洋岛民使用锯齿状鲨鱼牙齿作为工具和武器的组成部分。他们这样做是因为锯齿状鲨鱼牙齿在切割软组织方面非常有效。为了更多地了解锯齿状鲨鱼牙齿的形式和功能，我们研究了三个物种的牙齿锯齿的形态和组织学：虎鲨（Galeocerdo cuvier）、蓝鲨（Prionace glauca）和白鲨（Carcharodon carcharias）。我们证明了锯齿有两种基本类型。主要锯齿由三层釉质组成，下面的牙本质填充锯齿的基部。研究的所有三个物种都有初级锯齿，尽管牙本质成分不同（老虎和蓝鲨的牙本质；白鲨的骨牙本质）。在虎鲨中发现了较小的次生锯齿，这些锯齿仅由釉质形成，没有来自底层牙本质的贡献。二级锯齿实际上是“锯齿中的锯齿”，允许牙齿以不同的尺寸进行切割。我们认为，虎鲨牙齿的尖端配有不同尺度的锯齿，与包括大型硬壳猎物（例如海龟）以及较小、较软的猎物（例如鱼类）的饮食有关。我们通过与人造切割工具（例如刀和锯）进行类比来讨论锯齿形式和功能的其他方面。
Prior to European contact, South Pacific islanders used serrated shark teeth as components of tools and weapons. They did this because serrated shark teeth are remarkably effective at slicing through soft tissues. To understand more about the forms and functions of serrated shark teeth, we examined the morphology and histology of tooth serrations in three species: the Tiger Shark (Galeocerdo cuvier), Blue Shark (Prionace glauca), and White Shark (Carcharodon carcharias). We show that there are two basic types of serrations. A primary serration consists of three layers of enameloid with underlying dentine filling the serration’s base. All three species studied have primary serrations, although the dentine component differs (orthodentine in Tiger and Blue Sharks; osteodentine in the White Shark). Smaller secondary serrations are found in the Tiger Shark, formed solely by enameloid with no contribution from underlying dentine. Secondary serrations are effectively “serrations within serrations” that allow teeth to cut at different scales. We propose that the cutting edges of Tiger Shark teeth, equipped with serrations at different scales, are linked to a diet that includes large, hard-shelled prey (e.g., sea turtles) as well as smaller, softer prey such as fishes. We discuss other aspects of serration form and function by making analogies to man-made cutting implements, such as knives and saws.