SIZE VARIABILITY OF THE TEETH IN LIVING MAMMALS AND THE DIAGNOSIS OF CLOSELY RELATED SYMPATRIC FOSSIL SPECIES
SIZE VARIABILITY OF THE TEETH IN LIVING MAMMALS AND THE DIAGNOSIS OF CLOSELY RELATED SYMPATRIC FOSSIL SPECIES
复制标题
活体哺乳动物牙齿大小的变异性及密切相关的同域化石种的诊断
DOI：
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发表时间：
1974
期刊：
影响因子：
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通讯作者：
P. Gingerich
中科院分区：
文献类型：
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作者：
P. Gingerich
同域的化石（或现存的）哺乳动物物种有一个相对较近的共同祖先，它们的牙列往往不能单凭形式来区分。在这种情况下，大小差异对诊断物种很重要。对19种现存哺乳动物大样本的下磨牙和前磨牙的长度和宽度的测量表明，M1通常是尺寸变化最小的，而P3、P4和M3是变化最大的。M1的低变异性可能与它是第一个形成和长出的恒牙，以及它在牙齿排中的中心位置有关。由于它的低变异性，M1是对非常密切相关的同域化石物种进行大小诊断的最佳依据。给出了两种灵长目化石Plesiadapis （Cernay）、Pelycodus （Avenay）和Protoadapis （Grauves）的诊断实例。区分密切相关的同域物种的能力对于从化石记录中重建任何类群的系统发育历史都是至关重要的。
The dentitions of sympatric fossil (or living) mammalian species which share a relatively recent common ancestor often cannot be distinguished by form alone. In such cases, size differences are important in diagnosing the species. Measurements of the length and width of the lower molars and premolars of large samples of 19 species of living mammals demonstrate that M1 is usually the least variable in size, and that P3, P4, and M3 are the most variable. The low variability of M1 is presumably related to the fact that it is the first permanent tooth to form and erupt, and to its central position in the tooth row. Because of its low variability, M1 is the best tooth on which to base size diagnoses of very closely related sympatric fossil species. Examples are given of the diagnosis of two species of the fossil primates Plesiadapis (at Cernay), Pelycodus (at Avenay), and Protoadapis (at Grauves). The ability to distinguish closely related sympatric species is fundamental to reconstructing the phylogenetic history of any group from the fossil record.