Evolution of the sabertooth mandible: A deadly ecomorphological specialization
Evolution of the sabertooth mandible: A deadly ecomorphological specialization
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剑齿虎下颌骨的进化：致命的生态形态专业化
DOI：
10.1016/j.palaeo.2018.01.034
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发表时间：
2018
期刊：
影响因子：
--
通讯作者：
P. Raia
中科院分区：
文献类型：
--
作者：
P. Piras;D. Silvestro;F. Carotenuto;S. Castiglione;A. Kotsakis;L. Maiorino;M. Melchionna;A. Mondanaro;G. Sansalone;C. Serio;V. A. Vero;P. Raia
剑齿猫拥有强大的武器。它们进化出许多高度衍生的形态特征，最显著的是一对极长的上犬齿，这使它们在猫科动物家族中独一无二。虽然剑齿虎的特征在食肉哺乳动物中进化了几次，但剑齿虎的分支大多在空间和时间上都是分离的，今天没有剑齿虎存活。我们研究了剑齿虎的下颌骨的表型和分类多样化的速度，相比灭绝和现存的圆锥齿猫计算的速度。我们发现剑齿虎分支中的下颌骨的形状和物理特性的进化速度明显高于猫科动物树的其他部分。此外，剑齿虎的物种形成率与锥齿猫相似，但灭绝率在统计学上更高。剑齿虎需要丰富的形态特化，以及它们倾向于将大型物种作为猎物，这可能是导致如此高灭绝率的原因，也是化石记录中剑齿虎分支出现的特殊分离模式的原因。
Saber-toothed cats were armed with formidable weapons. They evolved a number of highly derived morphological features, most notably a pair of extremely long upper canines, which makes them unique within the felid family. Although the sabertooth character evolved several times among carnivorous mammals, sabertooth clades mostly had disjunctive occurrences both in space and time, and no sabertooth is alive today. We studied the rates of phenotypic and taxonomic diversification in the mandible of sabertooths, as compared to the rates calculated for both extinct and extant conical toothed cats. We found that the mandible's shape and physical properties in sabertooth clades evolved at distinctly higher rates than the rest of the felid tree. In addition, sabertooths had similar speciation rate to conical toothed cats, but statistically higher extinction rate. The wealth of morphological specializations required to be a sabertooth, and their tendency to focus on large-sized species as prey, was likely responsible for such high extinction rate, and for the peculiar, disjunctive patterns of sabertooth clade occurrence in the fossil record.