Interdepartmental Doctoral Program in Anthropological Sciences, Stony Brook University, Stony Brook, NY, 11794-4364; Institute of Biotechnology, University of Helsinki, Helsinki, 00014, Finland.
Am J Phys Anthropol. 2014 Jan;153(1):29-44. doi: 10.1002/ajpa.22398. Epub 2013 Nov 7.
Dental topographic analysis is the quantitative assessment of shape of three-dimensional models of tooth crowns and component features. Molar topographic curvature, relief, and complexity correlate with aspects of feeding behavior in certain living primates, and have been employed to investigate dietary ecology in extant and extinct primate species. This study investigates whether dental topography correlates with diet among a diverse sample of living platyrrhines, and compares platyrrhine topography with that of prosimians. We sampled 111 lower second molars of 11 platyrrhine genera and 121 of 20 prosimian genera. For each tooth we calculated Dirichlet normal energy (DNE), relief index (RFI), and orientation patch count (OPCR), quantifying surface curvature, relief, and complexity respectively. Shearing ratios and quotients were also measured. Statistical analyses partitioned effects of diet and taxon on topography in platyrrhines alone and relative to prosimians. Discriminant function analyses assessed predictive diet models. Results indicate that platyrrhine dental topography correlates to dietary preference, and platyrrhine-only predictive models yield high rates of accuracy. The same is true for prosimians. Topographic variance is broadly similar among platyrrhines and prosimians. One exception is that platyrrhines display higher average relief and lower relief variance, possibly related to lower relative molar size and functional links between relief and tooth longevity distinct from curvature or complexity. Explicitly incorporating phylogenetic distance matrices into statistical analyses of the combined platyrrhine-prosimian sample results in loss of significance of dietary effects for OPCR and SQ, while greatly increasing dietary significance of RFI.
牙冠三维模型的拓扑分析是对形状的定量评估，其包括牙尖和组成特征。在某些现生灵长类动物中，磨牙的拓扑曲率、起伏和复杂度与摄食行为的某些方面相关，并且已被用于研究现生和已灭绝灵长类动物的饮食生态学。本研究调查了在多样化的现存阔鼻猴类样本中，牙冠拓扑结构是否与饮食相关，并比较了阔鼻猴类和原猴类的牙冠拓扑结构。我们对 11 个阔鼻猴类属的 111 颗下第二臼齿和 20 个原猴类属的 121 颗下第二臼齿进行了取样。对于每颗牙齿，我们计算了 Dirichlet 正态能量（DNE）、起伏指数（RFI）和定向斑块计数（OPCR），分别量化表面曲率、起伏和复杂度。我们还测量了剪切比和商。统计分析将饮食和分类群对阔鼻猴类牙冠拓扑结构的影响进行了分区，并与原猴类进行了比较。判别函数分析评估了预测饮食的模型。结果表明，阔鼻猴类的牙冠拓扑结构与饮食偏好相关，且仅针对阔鼻猴类的预测模型具有较高的准确性。原猴类也是如此。阔鼻猴类和原猴类的牙冠拓扑结构差异很大。一个例外是，阔鼻猴类的平均起伏度较高，起伏度方差较低，这可能与相对较小的磨牙尺寸以及与曲率或复杂度不同的与起伏度和牙齿寿命有关的功能联系有关。在对包含阔鼻猴类-原猴类混合样本的系统发育距离矩阵进行的统计分析中明确纳入这些矩阵，会导致 OPCR 和 SQ 的饮食影响失去显著性，而 RFI 的饮食显著性则大大增加。
