Data from: A novel, bounding gait in swimming turtles: implications for aquatic locomotor diversity

Turtles are an iconic lineage in studies of animal locomotion, typifying the use of slow, alternating footfalls during walking. Alternating movements of contralateral limbs are also typical during swimming gaits for most freshwater turtles. Here, we report a novel gait in turtles, in which the pleurodire (Emydura subglobosa) swims using a bounding gait that coordinates bilateral protraction of both forelimbs with bilateral retraction of both hindlimbs. Use of this bounding gait is correlated with increased limb excursion and decreased stride frequency, but not increased velocity when compared to standard swimming strokes. Bounding by <I>E. subglobosa </I> provides a second example of a non-mammalian lineage that can use bounding gaits, and may give insight into the evolution of aquatic flapping. Parallels in limb muscle fascicle properties between bounding turtles and crocodylids suggest a possible musculoskeletal mechanism underlying the use of bounding gaits in particular lineages.

龟类是动物运动学研究中的标志性类群，其行走行为以缓慢的交替步序为典型特征。对于多数淡水龟而言，游泳过程中的对侧肢体交替运动同样属于典型步态模式。
本研究报道了龟类的一种全新步态：侧颈龟亚目（Pleurodire）物种圆澳龟（Emydura subglobosa）在游泳时采用奔跃步态（bounding gait），该步态通过协调双侧前肢同时前伸与双侧后肢同时后伸来实现运动。
相较于常规游泳划水动作，该奔跃步态的使用与肢体位移幅度增大、步频降低呈相关关系，但并未提升游泳速度。
圆澳龟的奔跃步态是第二个可使用奔跃步态的非哺乳类类群实例，或可为水生肢体扑动的演化研究提供新的见解。
奔跃龟类与鳄科类群在肢体肌束特性上的相似性，暗示了特定类群采用奔跃步态背后可能存在的肌肉骨骼机制。