Abstract: The structure of the mammalian heart is associated with heart rate. Small-bodied shrews exhibit exceptionally high heart rates, accompanied by highly specialized cardiac anatomy. However, it remains unclear whether similar traits are present in larger-sized shrew species. Additionally, while previous studies have identified convergent evolution in heart-related genes between shrews and moles, it is not yet known whether such convergence also occurs at the anatomical level. In this study, we employed micro-CT technology to perform three-dimensional reconstructions of the hearts from representative species in Eulipotyphla including shrews (Soricidae), shrew moles (Talpidae), and gymnures (Erinaceidae). Our results show that, regardless of body size, shrew species possess remarkably consistent cardiac structures, characterized by an elongated left ventricle, thickened ventricular walls, and densely packed myocardial trabeculae. The heart anatomy of moles closely resembles that of shrews, whereas gymnures display typical mammalian heart morphology. These findings reveal a generalized anatomical adaptation of the shrew heart to high heart rates and provide morphological evidence for similar adaptations in moles, offering new insights into the adaptive evolution of the mammalian cardiovascular system.

Key words: Eulipotyphla, Cardiac anatomy, High heart rate, Three-dimensional reconstruction, Shrew

摘要： 哺乳动物的心脏结构与心率密切相关。体型小、心率快的鼩鼱科物种，其心脏展现出高度特化的解剖结构，但目前尚不清楚体型较大的鼩鼱科物种是否也具有相似特征。此外，尽管在基因水平上已发现鼩鼱科与鼹科动物在心脏相关基因上存在趋同现象，但其心脏解剖结构是否也表现出趋同尚未明确。本研究利用micro-CT技术，对劳亚食虫目中鼩鼱科、鼹科和猬科代表性物种的心脏进行了三维重建分析。结果显示：无论体型大小，鼩鼱科物种的心脏解剖结构均高度一致，表现为细长的左心室、增厚的心室壁以及致密的心肌小梁结构；鼹科物种的心脏解剖结构与鼩鼱科相似，而猬科动物则表现出典型的哺乳动物心脏结构。本研究揭示了鼩鼱科心脏解剖结构对高心率的普遍适应性，并为鼹科动物在解剖学层面上对高心率的适应提供了证据，从而为理解哺乳动物心脏的适应性演化提供了新的视角。

关键词: 劳亚食虫目, 心脏解剖结构, 高心率, 三维重建, 鼩鼱