Gliding is a distinctive locomotion type that has been identified in only three mammal species from the Mesozoic era. Here we describe another Jurassic glider that belongs to the euharamiyidan mammals and shows hair details on its gliding membrane that are highly similar to those of extant gliding mammals. This species possesses a five-boned auditory apparatus consisting of the stapes, incus, malleus, ectotympanic and surangular, representing, to our knowledge, the earliest known definitive mammalian middle ear. The surangular has not been previously identified in any mammalian middle ear, and the morphology of each auditory bone differs from those of known mammals and their kin. We conclude that gliding locomotion was probably common in euharamiyidans, which lends support to idea that there was a major adaptive radiation of mammals in the mid-Jurassic period. The acquisition of the auditory bones in euharamiyidans was related to the formation of the dentary-squamosal jaw joint, which allows a posterior chewing movement, and must have evolved independently from the middle ear structures of monotremes and therian mammals.

中文翻译：

---

侏罗纪滑行euharamiyidan哺乳动物，有五个听觉骨头的耳朵。

滑行是一种独特的运动类型，仅在中生代的三种哺乳动物中就已发现。在这里，我们描述了另一个属于euharamiyidan哺乳动物的侏罗纪滑翔机，并在滑行膜上显示了与现存滑行哺乳动物高度相似的毛发细节。该种具有五键听觉装置，由mall骨，in，槌骨，鼓膜外和上颚组成，据我们所知，代表着最早的确定的哺乳动物中耳。先前在任何哺乳动物的中耳中都没有发现过该矩形，并且每个听觉骨的形态与已知哺乳动物及其亲属的形态不同。我们得出的结论是，滑行运动在euharamiyidans中可能很常见，这支持了侏罗纪中期哺乳动物主要的适应性辐射的观点。euharamiyidans的听觉骨骼的获取与牙齿-鳞状颌骨关节的形成有关，该关节允许后咀嚼运动，并且必须独立于单眼和哺乳动物的中耳结构而发展。