Evolution of the middle ear apparatus in talpid moles
Evolution of the middle ear apparatus in talpid moles
复制标题
痣中耳器的进化
作者：
M. Mason
用光镜和电镜观察了8种鼹鼠中耳的结构。Neurotrichus，Parascalops和Condylura有一个简单的中耳腔，有一个松散的外鼓室骨，一个“微型”形态的听小骨，它们保留了一个小的鼓膜张肌。这些特征是胎痣的祖先。另一方面，Talpa，Scalopus，Scapanus和Parascaptor物种在锤骨和外鼓室骨之间具有较松的关节，并且圆形骨突减少或缺失。这些物种缺乏鼓膜张肌，拥有完整的大疱，并且中耳腔的延伸使周围的颅底骨变圆。两个中耳腔在Talpa，Scapanus和Parascaptor物种中沟通。副捕鳄有一个肥大的锤骨，这是一个与Scaptochirus共有的特征，但在任何其他的talpid属中都没有发现。Talpidae成员之间中耳形态的差异与生活方式相关。中耳更接近祖先类型的物种在地面上花费更多的时间，在那里他们将暴露在高频声音中：他们的中耳似乎适合高频传输。具有衍生中耳形态的物种更专门地在地下。他们中耳的一些衍生特征可能会改善低频听力，而其他特征可能会减少骨传导噪声的传播。相比之下，Parascaptor不寻常的中耳装置，表现出惊人的相似之处，金鼹鼠，可能通过惯性骨传导增加地震敏感性。J. Morphol.© 2006 Wiley利斯公司
The middle ear structures of eight species of mole in the family Talpidae (Mammalia: Eulipotyphla) were studied under light and electron microscopy. Neurotrichus, Parascalops, and Condylura have a simple middle ear cavity with a loose ectotympanic bone, ossicles of a “microtype” morphology, and they retain a small tensor tympani muscle. These characteristics are ancestral for talpid moles. Talpa, Scalopus, Scapanus, and Parascaptor species, on the other hand, have a looser articulation between malleus and ectotympanic bone and a reduced or absent orbicular apophysis. These species lack a tensor tympani muscle, possess complete bullae, and extensions of the middle ear cavity pneumatize the surrounding basicranial bones. The two middle ear cavities communicate in Talpa, Scapanus, and Parascaptor species. Parascaptor has a hypertrophied malleus, a feature shared with Scaptochirus but not found in any other talpid genus. Differences in middle ear morphology within members of the Talpidae are correlated with lifestyle. The species with middle ears closer to the ancestral type spend more time above ground, where they will be exposed to high‐frequency sound: their middle ears appear suited for transmission of high frequencies. The species with derived middle ear morphologies are more exclusively subterranean. Some of the derived features of their middle ears potentially improve low‐frequency hearing, while others may reduce the transmission of bone‐conducted noise. By contrast, the unusual middle ear apparatus of Parascaptor, which exhibits striking similarities to that of golden moles, probably augments seismic sensitivity by inertial bone conduction. J. Morphol. © 2006 Wiley‐Liss, Inc.
影响因子：
2.4
作者：
Overstreet, EH;Ruggero, MA
通讯作者：
Ruggero, MA