Often the first point of contact between predator and prey, mammalian canine teeth are essential for killing, dismembering and consuming prey. Yet despite their importance, few associations among shape, function and phylogeny are established. We undertook the first comprehensive analysis of canine tooth shape across predatory mammals (Carnivora, Didelphimorphia and Dasyuromorphia), integrating shape analysis with function of this fundamental feature. Shape was quantified using three-dimensional geometric morphometrics and cross-sectional sharpness. Canines vary in three main ways (sharpness, robustness and curvature) which vary with diet, killing behaviour and phylogeny. Slender, sharp canines are associated with carnivores such as felids that target the neck of their prey and primarily consume the ‘softer’ parts of a carcass. Robust, blunt canines are found in mustelids and dasyurids that typically consume ‘harder’ materials, such as bone, or bite into skulls. Differences in the killing behaviours of felids and canids probably result in more curved canines in the latter, which act as hooks to hold prey. We find functional specialization in the upper and lower canines of individuals and across the major mammalian clades. These patterns demonstrate how canine teeth are adapted to suit diverse diets and hunting styles, enabling mammals to become some of nature's most successful predators.

中文翻译：

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杀手的工具包：哺乳动物食肉动物犬齿的显着适应

哺乳动物犬齿通常是捕食者和猎物之间的第一个接触点，对于杀死、肢解和食用猎物至关重要。然而，尽管它们很重要，但几乎没有建立形状、功能和系统发育之间的关联。我们对掠食性哺乳动物（Carnivora、Didelphimorphia 和 Dasyuromorphia）的犬齿形状进行了首次综合分析，将形状分析与这一基本特征的功能相结合。使用三维几何形态计量学和横截面清晰度对形状进行量化。犬科动物以三种主要方式（锋利度、健壮性和弯曲度）变化，这些方式随饮食、杀戮行为和系统发育而变化。细长、锋利的犬科动物与食肉动物有关，例如猫科动物，它们以猎物的颈部为目标，主要消耗尸体的“较软”部分。强壮的，钝尖的犬齿存在于鼬科动物和达苏尔科动物中，它们通常消耗“较硬”的材料，例如骨头，或咬入头骨。猫科动物和犬科动物捕杀行为的差异可能导致后者的犬齿弯曲更多，充当钩住猎物的钩子。我们发现个体上犬齿和下犬齿以及主要哺乳动物进化枝的功能特化。这些模式展示了犬齿如何适应不同的饮食和狩猎方式，使哺乳动物成为自然界最成功的捕食者。我们发现个体上犬齿和下犬齿以及主要哺乳动物进化枝的功能特化。这些模式展示了犬齿如何适应不同的饮食和狩猎方式，使哺乳动物成为自然界最成功的捕食者。我们发现个体上犬齿和下犬齿以及主要哺乳动物进化枝的功能特化。这些模式展示了犬齿如何适应不同的饮食和狩猎方式，使哺乳动物成为自然界最成功的捕食者。