Biomechanical insights into the dentition of megatooth sharks (Lamniformes: Otodontidae).
Biomechanical insights into the dentition of megatooth sharks (Lamniformes: Otodontidae).
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巨齿鲨齿系的生物力学研究（Lamniformes：Otodontidae）。
DOI：
10.1038/s41598-020-80323-z
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发表时间：
2021-01-13
影响因子：
4.6
通讯作者：
Ferrón HG
中科院分区：
文献类型：
--
作者：
Ballell A;Ferrón HG
在已灭绝的耳齿鲨中，巨人症的进化与它们牙列的一系列剧烈变化是平行的，包括牙冠变宽，侧齿瓣的丧失，以及获得锯齿状的切削刃。这些特征通常被解释为关键的功能特征，使鱼类能够过渡到以海洋哺乳动物为基础的更有活力的饮食，最终导致了最近形式的巨大体型的进化（包括标志性的巨齿鲨）。为了验证这一假设，我们采用二维有限元分析方法评估了五种耳齿动物在不同载荷条件下的前、侧、后牙的生物力学。所有模型在穿刺和拉伸（即分别受到垂直和侧向力）下的应力分布模式非常相似。与预期相反，在最近的物种中，在两种加载情况下检测到更高的平均应力值。总之，这表明齿状突动物的牙齿形态与生物力学行为的关键方面之间几乎没有相关性，这使得在适应情景中构建齿状突的形态趋势变得困难。我们认为，这种模式很可能是由体型选择驱动的异时过程的非功能性副产品。
The evolution of gigantism in extinct otodontid sharks was paralleled by a series of drastic modifications in their dentition including widening of the crowns, loss of lateral cusplets, and acquisition of serrated cutting edges. These traits have generally been interpreted as key functional features that enabled the transition from piscivory to more energetic diets based on marine mammals, ultimately leading to the evolution of titanic body sizes in the most recent forms (including the emblematic Otodus megalodon). To investigate this hypothesis, we evaluate the biomechanics of the anterior, lateral, and posterior teeth of five otodontid species under different loading conditions by using two-dimensional finite element analysis. Stress distribution patterns are remarkably similar among all models under puncture and draw (i.e., when subjected to vertical and lateral forces, respectively). Contrary to expectation, higher average stress values are detected under both loading scenarios in more recent species. Altogether, this suggests little correlation between tooth morphology and key aspects of biomechanical behaviour in otodontids, making it difficult to frame the morphological trend of their dentitions within an adaptive scenario. We propose that this pattern most likely emerged as a non-functional by-product of heterochronic processes driven by selection towards larger body sizes.
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影响因子：
2.7
作者：
Boessenecker, Robert W.;Ehret, Dana J.;Boessenecker, Sarah J.
通讯作者：
Boessenecker, Sarah J.
影响因子：
3.7
作者：
Ferron, Humberto G.
通讯作者：
Ferron, Humberto G.
DOI：
10.1016/j.palaeo.2017.01.001
发表时间：
2017-03-01
影响因子：
3
作者：
Collareta, Alberto;Lambert, Olivier;Bianucci, Giovanni
通讯作者：
Bianucci, Giovanni
影响因子：
2
作者：
Dumont, E. R.;Grosse, I. R.;Slater, G. J.
通讯作者：
Slater, G. J.
影响因子：
2.6
作者：
Ehret, Dana J.;Macfadden, Bruce J.;Salas-Gismondi, Rodolfo
通讯作者：
Salas-Gismondi, Rodolfo