Lemmus and Myopus are two lemming species with distinct habitat requirements but which show very similar dental morphologies. They are thus extremely difficult to distinguish from one another in the fossil record on the basis of their dental remains, leading to poor understanding of the palaeobiogeographical evolution of Myopus as well as inaccurate palaeoenvrionmental reconstructions. Currently, the presence of Myopus in the fossil register from the Pleistocene is still debated and no firm occurrence of this lemming in western Europe has yet been confirmed for the Late Pleistocene. In this paper, we used geometric morphometrics on modern material to establish morphological differences between Lemmus and Myopus teeth (first lower and third upper molars). Morphological data were then used to build a robust linear discriminant model able to confidently classify isolated teeth of these two genera, and finally, linear discriminant models were used on fossil remains of Lemmus/Myopus from two Late Pleistocene archaeological/palaeontological sites (Grotte des Gorges and Gully Cave). This study demonstrates, for the first time, the presence of Myopus schisticolor in west European Late Pleistocene sites between the end of Marine Isotope Stage 3 and the beginning of the Holocene, during climatic events that favoured the development of taiga forest of birch and pine in these regions.

中文翻译：

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失踪的Myopus：用几何形态计量学填补了西欧晚更新世小型哺乳动物鉴定中的空白

mm鼠和近足猴是两个具有不同栖息地要求的旅鼠，但它们显示出非常相似的牙齿形态。因此，由于它们的牙齿残骸，它们在化石记录中很难彼此区分开，从而导致人们对Myopus的古生物地理演化以及不准确的古环境重建缺乏了解。目前，关于更新世的化石记录中存在着Myopus的争论仍在争论中，而在晚更新世的西欧，尚未证实这种旅鼠的确有发生。在本文中，我们对现代材料使用了几何形态计量学，以建立Lemmus和Myopus牙齿（第一下磨牙和第三上磨牙）之间的形态学差异。然后，使用形态学数据建立能够可靠地对这两个属的孤立牙齿进行分类的鲁棒线性判别模型，最后，将线性判别模型用于两个更新世晚期考古/古生物学遗址（Grotte des Gorges）的Lemmus / Myopus的化石残骸上。和Gully Cave）。这项研究首次证明，在有利于白桦和松树针叶林针叶林发展的气候事件期间，在海洋同位素第3阶段结束至全新世开始之间的西欧晚更新世遗址中存在鼠尾草（Myopus schisticolor）。这些地区。线性判别模型用于来自两个晚更新世考古/古生物学遗址（格罗特·德·乔治和古利洞）的莱姆斯/近视动物的化石残骸。这项研究首次证明，在有利于白桦和松树针叶林针叶林发展的气候事件期间，在海洋同位素第3阶段结束至全新世开始之间的西欧晚更新世遗址中存在鼠尾草（Myopus schisticolor）。这些地区。线性判别模型用于来自两个晚更新世考古/古生物学遗址（格罗特·德·乔治和古利洞）的莱姆斯/近视动物的化石残骸。这项研究首次证明，在有利于白桦和松树针叶林针叶林发展的气候事件期间，在海洋同位素第3阶段结束至全新世开始之间的西欧晚更新世遗址中存在鼠尾草（Myopus schisticolor）。这些地区。