Data from: The impact of digging on craniodental morphology and integration

The relationship between the form and function of the skull has been the subject of a great deal of research, much of which has concentrated on the impact of feeding on skull shape. However, there are a number of other behaviours that can influence craniodental morphology. Previous work has shown that subterranean rodents that use their incisors to dig (chisel-tooth digging) have a constrained cranial shape which is probably driven by a necessity to create high bite forces at wide gapes. Chisel-tooth digging rodents also have an upper incisor root that is displaced further back into the cranium compared with other rodents. This study quantified cranial shape and upper incisors of a phylogenetically diverse sample of rodents to determine if chisel-tooth digging rodents differ in craniodental morphology. The study showed that the crania of chisel-tooth digging rodents shared a similar place in morphospace, but a strong phylogenetic signal within the sample meant that this grouping was non-significant. It was also found that the curvature of the upper incisor in chisel-tooth diggers was significantly larger than in other rodents. Interestingly, most subterranean rodents in the sample (both chisel-tooth and scratch diggers) had upper incisors that were better able to resist bending than those of terrestrial rodents, presumably due to their similar diets of tough plant materials. Finally, the incisor variables and cranial shape were not found to covary consistently in this sample, highlighting the complex relationship between a species’ evolutionary history and functional morphology.颅骨形态与功能之间的关联一直是诸多研究的核心议题，其中绝大多数研究聚焦于取食行为对颅骨形态的影响。然而，尚有诸多其他行为可对颅齿形态（craniodental morphology）产生影响。已有研究表明，以门齿掘土的凿齿掘土（chisel-tooth digging）啮齿类，其颅骨形态受到限制，这一限制可能源于其需要在大张口状态下产生高咬合力。与其他啮齿类相比，凿齿掘土啮齿类的上门齿牙根更向颅腔内后移。本研究对具有系统发育多样性的啮齿类样本的颅骨形态与上门齿特征进行了量化分析，以探究凿齿掘土啮齿类是否在颅齿形态上存在差异。研究结果显示，凿齿掘土啮齿类的颅骨在形态空间中占据相似的位置，但样本中较强的系统发育信号使得该类群的分组显著性检验未获支持。此外，研究还发现凿齿掘土啮齿类的上门齿曲率显著大于其他啮齿类。值得注意的是，样本中的绝大多数地下啮齿类（包括凿齿掘土与爪掘掘土两类），其上门齿抗弯曲能力均优于地表啮齿类，这一现象大概率与其均取食坚韧植物材料的食性相关。最后，本研究未发现样本中门齿特征与颅骨形态存在稳定的协变关系，这凸显了物种演化历史与功能形态之间的复杂关联。