Prikryl Tomás, Aerts Peter, Havelková Pavla, Herrel Anthony, Rocek Zbynek
Department of Paleobiology, Geological Institute, Academy of Sciences, Prague, Czech Republic.
J Anat. 2009 Jan;214(1):100-39. doi: 10.1111/j.1469-7580.2008.01006.x.
Comparative analysis of the anuran pelvic and thigh musculoskeletal system revealed that the thigh extensors, responsible for the initial phase of jump, the propulsive stroke in swimming and, if used asynchronously, also for walking, are least affected by the transformations observed between anurans and their temnospondyl ancestors (as reflected in contemporary caudates). The iliac shaft and urostyle, two of the most important anuran apomorphies, represent skeletal support for muscles that are mostly protractors of the femur or are important in attaining a crouching position, a necessary prerequisite for rapid escape. All of these muscles originate or insert on the iliac shaft. As the orientation of the pubis, ischium and ilium is the same in anurans, caudates and by inference also in their temnospondyl ancestors, it is probable that the pelvis was shifted from the sacral vertebra posteriorly along the reduced and stiffened tail (urostyle) by the elongation of the illiac shaft. Thus, the original vertical orientation of the ilium was maintained (which is also demonstrated by stable origins of the glutaeus maximus, iliofemoralis and iliofibularis on the tuber superius) and the shaft itself is a new structure. A review of functional analysis of anuran locomotion suggests some clear differences from that in caudates, suggesting that terrestrial jumping may have been a primary locomotor activity, from which other types of anuran locomotion are derived.
对无尾两栖动物骨盆和大腿肌肉骨骼系统的比较分析表明，负责跳跃初始阶段、游泳推进冲程的大腿伸肌，以及在异步使用时也负责行走的大腿伸肌，受无尾两栖动物与其离片锥目祖先之间所观察到的转变影响最小（当代有尾两栖动物也反映了这种转变）。髂骨和尾杆骨是无尾两栖动物最重要的两个衍生特征，它们为大多是股骨前拉肌的肌肉或在获得蹲伏姿势（快速逃脱的必要前提）中起重要作用的肌肉提供骨骼支撑。所有这些肌肉都起源于或附着在髂骨上。由于无尾两栖动物、有尾两栖动物以及由此推断其离片锥目祖先的耻骨、坐骨和髂骨方向相同，很可能是髂骨的延长使骨盆从骶椎沿着缩短且变硬的尾巴（尾杆骨）向后移动。因此，髂骨原来的垂直方向得以保持（臀大肌、髂股肌和髂腓肌在髂骨上的稳定起源也证明了这一点），而髂骨本身是一个新结构。对无尾两栖动物运动功能分析的综述表明，其与有尾两栖动物的运动功能存在一些明显差异，这表明陆地跳跃可能是一种主要的运动活动，其他类型的无尾两栖动物运动由此衍生而来。
