Evolution and Morphological Variability of Cheek Teeth in the Kudaro Cave Bear (Ursus kudarensis, Carnivora, Ursidae)

Baryshnikov G. F.; Puzachenko A. Y.

摘要

The variability of cheek teeth over time was studied with the use of univariate and multivatiate statistical analyses for 1370 tooth specimens of the Kudaro cave bear (Ursus kudarensis) (Baryshnikov 1985) collected in the Kudaro 1 and Kudaro 3 caves in the Caucasus. The material examined included two chronosubspecies: U. k. praekudarensis (middle part of the Middle Pleistocene, nearly 350 000 years ago) and U. k. kudarensis (Late Pleistocene, nearly 120 000-40 000 years ago), as well as a sample of intermediate stratigraphic position referred to as a "transitional form" (the end of the Middle Pleistocene, nearly 250 000 years ago). Our study detected no single pathway of evolutionary change in the cheek teeth of U. kudarensis, instead showing specific modifications for the premolars, molars, and even individual teeth (e.g., m3) in the context of high individual variability. In size, the teeth of U. k. praekudarensis occupied an intermediate position between the more robust teeth of the "transitional form" and the smaller teeth of U. k. kudarensis. By the range of morphometric characters (size and crown proportions), the "transitional form" was more closely related to U. k. kudarensis than to U. k. praekudarensis. At the same time, the parameters of allometric variation of the "transitional form" either related it to U. k. praekudarensis or were of the original nature. The calculated rate of evolution of the metric characters was found to be dissimilar not only for different teeth but also for different measurements of the same tooth crown, and these modifications themselves were oppositely directed. A comparison with the main evolutionary trends in European cave bears revealed the unique, independent character of evolution of the cheek teeth in the Kudaro cave bear, which is expressed to different degrees for the upper and lower rows of teeth.

机译：通过使用单变量和多师统计分析来研究脸颊牙齿随着时间的变化，用于在高加索1和Kudaro 3洞穴中收集的Kudaro洞穴熊（Baryshnikov 1985）中的1370颗牙齿标本（Baryshnikov 1985）。所检查的材料包括两个计时器：U. K. Praekudarensis（中间人科目的中部，近350 000年前）和U. K. Kudarensis（晚熟，近120 000-40 000年前），以及称为“过渡形式”（中间级联的末端，近25万年前）的中间地层位置样本。我们的研究检测到U. Kudarensis的脸颊牙齿的进化变化的单一途径，而是在高个体变异性的背景下显示出对磨牙，臼齿，甚至个体牙齿（例如，M3）的特定修改。大小，U. K的牙齿。 Praekudarensis占据了“过渡形式”的更强大的牙齿和U.K的较小牙齿之间的中间位置。 Kudarensis。通过形态学的范围（大小和冠比例），“过渡形式”与U.K更密切相关。 Kudarensis比U. K. Praekudarensis。同时，“过渡形式”的各种变化的参数与U.K相关。 praekudarensis或原始性质。发现计算的度量字符的演化速率不仅具有不同的牙齿，而且对于不同齿冠的不同测量，并且这些修改本身对其相反。与欧洲洞穴熊的主要进化趋势的比较揭示了Kudaro洞穴熊在颊牙的脸颊牙齿的进化的独特独立性，这表达了牙齿上下行和下排的不同程度。

Evolution and Morphological Variability of Cheek Teeth in the Kudaro Cave Bear (Ursus kudarensis, Carnivora, Ursidae)

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