| Abstract Scope |
Convergent evolution suggests that similar ecological pressures repeatedly favor comparable functional solutions, yet the underlying biomechanical mechanisms remain poorly understood. Parrotfishes independently evolved fused, beak-like dentition multiple times, but the mechanical advantages of this morphology have not been quantified. Here, we combine image-based finite element analysis with shockwave modeling to investigate stress redistribution during feeding. Across five species representing independent evolutionary origins of beaked and non-beaked dentitions, jaw opening is governed primarily by geometric scaling, with little influence from dentition morphology. Under stabilized biting, however, fused dentition reduces stress accumulation compared with discrete teeth, indicating improved load management. Shockwave simulations further show that smooth tooth profiles and stacked architectures regulate stress propagation by localizing stresses within the dentition and limiting transmission to the surrounding bone. These findings identify stress redistribution, rather than increased strength alone, as a key biomechanical principle underlying convergent evolution of parrotfish beaks. |