Suwa G, Wood B A, White T D
Department of Anthropology, Graduate School of Science, University of Tokyo, Japan.
Am J Phys Anthropol. 1994 Apr;93(4):407-26. doi: 10.1002/ajpa.1330930402.
Crown and cusp areas of mandibular molars were measured and analyzed on a sample of 249 specimens attributed to Australopithecus afarensis, A. africanus, A. (Paranthropus) robustus, A. (P.) boisei, and early Homo. In addition to intertaxon comparisons, we compared data that had been collected independently by two of the authors using methods that differ slightly in technique of measurement. Interobserver differences were evaluated by the t-test of paired comparisons, method error statistic, percent differences, and principal component analysis. Results suggest that between-technique error of measurement of overall crown area is small. Error estimates for individual cusp area measurements were of larger relative magnitude. However, these were not sufficient to detract from the conclusions derived from comparative analyses. Our results are in general agreement with previous assessments of early hominid dental size. Crown areas of A. africanus, however, exhibit a mosaic pattern, with M1 similar in size to that of A. afarensis and early Homo, and M2 and M3 similar in size to that of A. robustus. Intertaxon comparisons of relative cusp area were undertaken by univariate statistics and principal component analysis. These analyses revealed that while A. (P.) robustus and A. (P.) boisei both possess mandibular molars with cusp proportions significantly different from the 'non-robust' taxa, these differences are substantially greater in A. (P.) boisei.
在一个包含249个标本的样本上，对南方古猿阿法种、非洲南方古猿、粗壮傍人、鲍氏傍人和早期人类的下颌磨牙的牙冠和牙尖区域进行了测量和分析。除了分类单元间的比较，我们还比较了两位作者分别独立收集的数据，他们使用的测量技术略有不同。通过配对比较的t检验、方法误差统计、百分比差异和主成分分析来评估观察者间的差异。结果表明，牙冠总面积测量的技术间误差较小。单个牙尖面积测量的误差估计相对幅度较大。然而，这些并不足以削弱从比较分析得出的结论。我们的结果总体上与之前对早期人类牙齿大小的评估一致。然而，非洲南方古猿的牙冠面积呈现出一种镶嵌模式，M1的大小与阿法南方古猿和早期人类的相似，而M2和M3的大小与粗壮傍人的相似。通过单变量统计和主成分分析对牙尖面积的相对分类单元间进行比较。这些分析表明，虽然粗壮傍人和鲍氏傍人的下颌磨牙牙尖比例与“非粗壮”分类单元有显著差异，但鲍氏傍人的这些差异要大得多。
