Relationships between the complexity of the cranial sutures and the inferred ecology of dicynodont synapsids are explored. Simple complexity indices based on degree of sutural interdigitation were calculated for 70 anomodont species and indicate that the naso-frontal sutures of Cistecephalidae, a clade inferred to be dedicated fossors based on aspects of postcranial morphology, are substantially more complex than those of other dicynodonts. The elevated complexity of the naso-frontal suture in this clade is interpreted as being related to compressive forces sustained during burrowing, paralleling the condition in some other fossorial vertebrate groups (e.g., amphisbaenians). The most highly interdigitated sutures in the cistecephalid skull are those oriented transversely to its long axis, which would experience the greatest longitudinal stresses from contact with the substrate. Although it is uncertain to what degree cistecephalid burrowing was based on scratch vs. head-lift digging, it is argued that the head played an important role during locomotion in this group. Increased sutural complexity, rather than cranial fusion, as an adaptation to resisting compressive forces during burrowing may be related to indeterminate growth in dicynodonts.

中文翻译：

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穴居二齿兽类颅缝复杂度升高

探讨了颅缝的复杂性与二齿兽类突触纲推断生态学之间的关系。对 70 种无齿动物物种计算了基于缝线交叉程度的简单复杂性指数，表明 Cistecephalidae 的鼻额缝线是一种根据颅后形态推断为专用化石的进化枝，比其他二齿兽类的复杂得多。该进化枝中鼻额缝合线的复杂性被解释为与挖洞期间承受的压缩力有关，与其他一些化石脊椎动物群（例如，两栖动物）的情况相似。cistecephalid 颅骨中最高度交叉的缝合线是横向于其长轴定向的缝合线，与基材接触时会承受最大的纵向应力。尽管尚不确定在何种程度上基于划伤和抬起头挖掘，但有人认为头部在该组的运动过程中发挥了重要作用。增加的缝合复杂性，而不是颅骨融合，因为在挖洞期间对抵抗压缩力的适应可能与二齿兽类的不确定生长有关。