Ontogenetic and Paleontologic Studies of the Mammalian Ear Region: Implications for the Higher-Level Phylogeny of Mammals

化石记录的证据表明，在从爬行动物到哺乳动物的进化过程中，头骨的耳朵区域发生了根本性的变化。许多这些变化涉及软组织结构（神经、动脉和静脉），如化石中的各种沟槽、管和孔所证明的那样。由于对现代哺乳动物耳区软组织结构的了解不足，我们在化石形式中解释这些骨骼特征的能力受到严重限制。收集现代哺乳动物的详细解剖数据，用于：(1)重建化石形式耳朵区域的软组织结构；(2)分析哺乳动物主要类群之间的进化关系。

Evidence from the fossil record reveals that the ear region of the skull changed radically during the evolutionary transition from reptiles to mammals. Many of these changes concerned soft- tissue structures (nerves, arteries, and veins), as evidenced by various grooves, canals, and foramina in the fossils. Our ability to interpret these bony features in fossil forms is severely limited by poor knowledge of soft-tissue structures in the ear region of modern mammals. Detailed anatomical data from modern mammals will be collected and used to: (1) reconstruct soft-tissue structures in the ear regions of fossil forms and (2) analyze the evolutionary relationships among the major groups of mammals.