Durophagy arose in the Cambrian and greatly influenced the diversification of biomineralized defensive structures throughout the Phanerozoic. Spinose gnathobases on protopodites of Cambrian euarthropod limbs are considered key innovations for shell-crushing, yet few studies have demonstrated their effectiveness with biomechanical models. Here we present finite-element analysis models of two Cambrian trilobites with prominent gnathobases—Redlichia rex and Olenoides serratus—and compare these to the protopodites of the Cambrian euarthropod Sidneyia inexpectans and the modern American horseshoe crab, Limulus polyphemus. Results show that L. polyphemus, S. inexpectans and R. rex have broadly similar microstrain patterns, reflecting effective durophagous abilities. Conversely, low microstrain values across the O. serratus protopodite suggest that the elongate gnathobasic spines transferred minimal strain, implying that this species was less well-adapted to masticate hard prey. These results confirm that Cambrian euarthropods with transversely elongate protopodites bearing short, robust gnathobasic spines were likely durophages. Comparatively, taxa with shorter protopodites armed with long spines, such as O. serratus, were more likely restricted to a soft food diet. The prevalence of Cambrian gnathobase-bearing euarthropods and their various feeding specializations may have accelerated the development of complex trophic relationships within early animal ecosystems, especially the ‘arms race' between predators and biomineralized prey.

中文翻译：

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寒武纪真节肢动物肢体的生物力学分析揭示了它们在咀嚼和吞食方面的有效性

硬吞噬在寒武纪出现并极大地影响了整个显生宙生物矿化防御结构的多样化。寒武纪真节肢动物肢体原足上的棘齿基被认为是破壳的关键创新，但很少有研究证明它们在生物力学模型中的有效性。在这里，我们展示了两种具有显着颚基的寒武纪三叶虫——Redlichia rex 和 Olenoides serratus——的有限元分析模型，并将这些模型与寒武纪真节肢动物 Sidneyia inexpectans 和现代美洲鲎、鲎的原足动物进行了比较。结果表明，L. polyphemus、S. inexpectans 和 R. rex 具有广泛相似的微应变模式，反映了有效的吞食能力。相反，O 上的微应变值较低。serratus protopodite 表明细长的有颌棘转移了最小的应变，这意味着该物种不太适合咀嚼坚硬的猎物。这些结果证实寒武纪真节肢动物具有横向拉长的原足体，带有短而坚固的有颌棘，可能是硬质噬菌体。相比之下，具有长刺的较短原足类群，如 O. serratus，更可能仅限于软食。寒武纪有颚类的真节肢动物的流行及其各种摄食特化可能加速了早期动物生态系统中复杂营养关系的发展，尤其是捕食者和生物矿化猎物之间的“军备竞赛”。这意味着该物种不太适应咀嚼坚硬的猎物。这些结果证实寒武纪真节肢动物具有横向拉长的原足体，带有短而坚固的有颌棘，可能是硬质噬菌体。相比之下，具有长刺的较短原足类群，如 O. serratus，更可能仅限于软食。寒武纪有颚类的真节肢动物的流行及其各种摄食特化可能加速了早期动物生态系统中复杂营养关系的发展，尤其是捕食者和生物矿化猎物之间的“军备竞赛”。这意味着该物种不太适应咀嚼坚硬的猎物。这些结果证实寒武纪真节肢动物具有横向拉长的原足体，带有短而坚固的有颌棘，可能是硬质噬菌体。相比之下，具有长刺的较短原足类群，如 O. serratus，更可能仅限于软食。寒武纪有颚类的真节肢动物的流行及其各种摄食特化可能加速了早期动物生态系统中复杂营养关系的发展，尤其是捕食者和生物矿化猎物之间的“军备竞赛”。带有长刺的较短原足类群，如 O. serratus，更可能仅限于软食。寒武纪有颚类的真节肢动物的流行及其各种摄食特化可能加速了早期动物生态系统中复杂营养关系的发展，尤其是捕食者和生物矿化猎物之间的“军备竞赛”。带有长刺的较短原足类群，如 O. serratus，更可能仅限于软食。寒武纪有颚类的真节肢动物的流行及其各种摄食特化可能加速了早期动物生态系统中复杂营养关系的发展，尤其是捕食者和生物矿化猎物之间的“军备竞赛”。