Pérez-Barbería F Javier, Gordon Iain J
The Macaulay Land Use Research Institute, Craigiebuckler, Aberdeen, AB15 8QH, Scotland, UK e-mail:
Oecologia. 1999 Feb;118(2):157-165. doi: 10.1007/s004420050714.
The relationship between jaw and skull morphology and feeding type (grazer, mixed feeder, browser, frugivorous, omnivorous) was analysed in 94 species of extant ungulates. A total of 21 morphological traits of the jaw and skull (17 and 4, respectively) were analysed using analysis of covariance, with body mass as covariate. To take into account the phylogenetic effect, simulations were generated under the Brownian motion model of character evolution. Analysis of covariance was applied to these simulations and the simulated F-ratios were used to assess the signification of the F-ratios for the real values of the traits. The feeding types had a weak effect on ungulate cranial and jaw morphology in comparison with the phylogenetic effect, since, before phylogeny correction, the analysis of covariance showed statistically significant differences associated with feeding type in 15 out of the 21 traits analysed. After controlling for phylogeny, only 2 significant traits remained, the length of the coronoid process and the occipital height. Omnivorous species had shorter coronoid processes than grazers or mixed feeders, and the occipital height was greater in the omnivorous species than in the grazers, mixed feeders or browsers. The coronoid process is involved in the generation of bite force, being the effective moment arm of the temporalis muscle, and occipital height is positively related to the force exerted by the temporalis muscle. This result matches the hypothesis that species with a toughness diet should show higher bite force ("toughness" describes the resistance of a material to being mechanically broken down). When the omnivorous species were excluded from the analysis, no differences in jaw and skull morphology were detected between the rest of the feeding types.
对94种现存有蹄类动物的颌骨与颅骨形态和取食类型（食草动物、混合取食者、食叶动物、食果动物、杂食动物）之间的关系进行了分析。使用协方差分析，以体重作为协变量，对颌骨和颅骨的总共21个形态特征（分别为17个和4个）进行了分析。为了考虑系统发育效应，在性状进化的布朗运动模型下生成了模拟数据。对这些模拟数据应用协方差分析，并使用模拟的F比率来评估性状实际值的F比率的显著性。与系统发育效应相比，取食类型对有蹄类动物颅骨和颌骨形态的影响较弱，因为在进行系统发育校正之前，协方差分析显示，在所分析的21个性状中，有15个与取食类型存在统计学上的显著差异。在控制了系统发育之后，仅剩下2个显著性状，即冠状突长度和枕部高度。杂食动物的冠状突比食草动物或混合取食者的短，杂食动物的枕部高度比食草动物、混合取食者或食叶动物的大。冠状突参与咬合力的产生，是颞肌的有效力臂，枕部高度与颞肌施加的力呈正相关。这一结果与以下假设相符，即饮食坚韧的物种应表现出更高的咬合力（“坚韧”描述了一种材料抵抗机械分解的能力）。当从分析中排除杂食动物物种时，在其余取食类型之间未检测到颌骨和颅骨形态的差异。
