Miniaturization has evolved repeatedly in frogs in the moist leaf litter environments of rainforests worldwide. Miniaturized frogs are among the world’s smallest vertebrates and exhibit an array of enigmatic features. One area where miniaturization has predictable consequences is the vestibular system, which acts as a gyroscope, providing sensory information about movement and orientation. We investigated the vestibular system of pumpkin toadlets, Brachycephalus (Anura: Brachycephalidae), a clade of miniaturized frogs from Brazil. The semicircular canals of miniaturized frogs are the smallest recorded for adult vertebrates, resulting in low sensitivity to angular acceleration due to insufficient displacement of endolymph. This translates into a lack of postural control during jumping in Brachycephalus and represents a physical constraint resulting from Poiseuille’s law, which governs movement of fluids within tubes.

中文翻译：

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半规管大小限制了小型青蛙的前庭功能

在全球热带雨林潮湿的落叶环境中，青蛙的小型化反复进化。微型青蛙是世界上最小的脊椎动物之一，并表现出一系列神秘的特征。小型化具有可预测后果的一个领域是前庭系统，它充当陀螺仪，提供有关运动和方向的感官信息。我们研究了南瓜蟾蜍的前庭系统，短头目（Anura：Brachycephalidae），一种来自巴西的小型青蛙进化枝。小型青蛙的半规管是成年脊椎动物记录的最小的，由于内淋巴位移不足，导致对角加速度的敏感性低。这意味着在跳跃过程中缺乏姿势控制短头目并表示由泊肃叶定律产生的物理约束，该定律控制管内流体的运动。