The largest extinct volant birds (Pelagornis sandersi and Argentavis magnificens) and pterosaurs (Pteranodon and Quetzalcoatlus) are thought to have used wind-dependent soaring flight, similar to modern large birds. There are two types of soaring: thermal soaring, used by condors and frigatebirds, which involves the use of updrafts to ascend and then glide horizontally over the land or the sea; and dynamic soaring, used by albatrosses, which involves the use of wind speed differences with height above the sea surface. Previous studies have suggested that Pelagornis sandersi used dynamic soaring, while Argenthavis magnificens, Pteranodon, and Quetzalcoatlus used thermal soaring. However, the performance and wind speed requirements of dynamic and thermal soaring for these species have not yet been quantified comprehensively. We quantified these values using aerodynamic models and compared them with that of extant birds. For dynamic soaring, we quantified maximum flight speeds and maximum upwind flight speeds. For thermal soaring, we quantified the animal′s sinking speed circling at a given radius and how far it could glide losing a given height. Our results confirmed those from previous studies that Pteranodon and Argentavis magnificens used thermal soaring. Conversely, the results for Pelagornis sandersi and Quetzalcoatlus were contrary to those from previous studies. Pelagornis sandersi used thermal soaring, and Quetzalcoatlus had a poor ability both in dynamic and thermal soaring. Our results demonstrate the need for comprehensive assessments of performance and required wind conditions when estimating soaring styles of extinct flying species.

中文翻译：

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灭绝的巨型鸟类和翼龙的飙升风格

与现代大型鸟类类似，据信灭绝的最大灭绝鸟类（Pelagornis sandersi和Argentavis magnificens）和翼龙（Pteranodon和Quetzalcoatlus）使用依赖风的高飞飞行。飙升有两种类型：秃鹰和护卫鸟使用的热力飙升，包括利用上升气流上升然后在陆地或海洋上水平滑行；以及 和信天翁使用的动态飙升，其中涉及使用风速差异与海平面以上的高度。先前的研究表明，Pelagornis sandersi使用动态腾飞，而阿根廷Argenthavis，Pteranodon和Quetzalcoatlus使用热腾飞。但是，这些物种动态和热腾腾的性能和风速要求尚未得到全面量化。我们使用空气动力学模型量化了这些值，并将其与现存鸟类的值进行了比较。对于动态飙升，我们量化了最大飞行速度和最大迎风飞行速度。对于热腾腾，我们量化了动物在给定半径处盘旋的下沉速度，以及在失去给定高度的情况下它可以滑行多远。我们的结果证实了先前研究的结果，即翼龙和Argentavis壮丽鱼使用了热腾飞。相反，Pelagornis sandersi和Quetzalcoatlus的结果与以前的研究结果相反。Pelagornis sandersi使用热腾腾，而Quetzalcoatlus在动态和热腾腾方面均表现较差。我们的结果表明，在估计灭绝的飞行物种的高飞样式时，需要对性能和所需的风况进行全面评估。