Institut Català de Paleontologia Miquel Crusafont (ICP-CERCA), Universitat Autònoma de Barcelona, Edifici ICTA-ICP, c/ Columnes s/n, 08193 Cerdanyola del Vallès, Barcelona, Spain.
Univ. Bordeaux, CNRS, MCC, PACEA, UMR 5199, F-33600 Pessac, France.
J Hum Evol. 2024 Oct;195:103581. doi: 10.1016/j.jhevol.2024.103581. Epub 2024 Sep 7.
The phylogenetic relationships of the small-bodied catarrhine Pliobates cataloniae (∼11.6 Ma, NE Iberian Peninsula) have been controversial since its original description. However, the recent report of additional dentognathic remains has supported its crouzeliid pliopithecoid status. Based on the available hypodigm, the molar enamel-dentine junction (EDJ) shape of P. cataloniae is compared with that of other pliopithecoids from the same basin as well as both extinct and extant hominoids to further evaluate its pliopithecoid affinities. We also quantitatively compare the EDJ shape among these taxa by means of landmark-based three-dimensional geometric morphometrics using principal component analysis (PCA), canonical variate analysis, and between-group PCA. Permutation tests are performed to test whether Pliobates variation exceeds that of extant hominoid genera. Results indicate that Pliobates is similar in molar EDJ shape to other pliopithecoids, particularly crouzeliids. The variation displayed by Pliobates upper molars is less marked at the EDJ level than at the outer enamel surface, probably owing to differential enamel wear and intraspecific differences in enamel thickness. Multivariate analyses of EDJ shape show that all pliopithecoids (including Pliobates) cluster together in the PCAs, canonical variate analyses, and between-group PCAs and occupy a different portion of the morphospaces from extinct and extant hominoids. Posterior and typicality probabilities strongly support the classification of Pliobates as a pliopithecoid, wheras permutation tests fail to reject the single-genus hypothesis for the P. cataloniae hypodigm. We conclude that P. cataloniae is a crouzeliid pliopithecoid, as recently supported by cladistic analyses of craniodental characters, and that previous cladistic results that supported a stem hominoid status are attributable to postcranial convergences with crown hominoids. Our results further highlight the potential of three-dimensional geometric morphometrics analyses of the EDJ shape for better informing fossil primate alpha-taxonomy by means of quantitatively testing hypotheses about tooth shape variation.
小型猫形类化石 Pliobates cataloniae（约 11.6 Ma，伊比利亚半岛东北部）自最初描述以来，其系统发育关系一直存在争议。然而，最近有关额外的牙齿化石的报道支持了其属于攀猴型类的地位。基于现有的标本，我们将 P. cataloniae 的臼齿釉牙骨质界（EDJ）形状与来自同一盆地的其他攀猴型类以及已灭绝和现生的人科进行了比较，以进一步评估其攀猴型类的亲缘关系。我们还通过基于地标三维几何形态测量学的主成分分析（PCA）、典型变量分析和组间 PCA 对这些分类单元的 EDJ 形状进行了定量比较。我们通过置换检验来检验 Pliobates 的变异是否超过现生人科属的变异。结果表明，Pliobates 的臼齿 EDJ 形状与其他攀猴型类相似，尤其是 crouzeliids。与外釉面相比，Pliobates 上臼齿的 EDJ 水平的变异不太明显，这可能是由于釉质磨损和种内釉质厚度的差异所致。EDJ 形状的多变量分析表明，所有的攀猴型类（包括 Pliobates）在 PCA、典型变量分析和组间 PCA 中聚在一起，并且在形态空间中占据了与已灭绝和现生人科不同的部分。后验概率和典型性概率强烈支持将 Pliobates 归类为攀猴型类，而置换检验未能否定 P. cataloniae 标本的单属假说。我们得出结论，P. cataloniae 是 crouzeliid 攀猴型类，正如最近基于颅面特征的分支分析所支持的那样，而先前支持原始人科地位的分支分析结果归因于与人科冠部的后肢趋同。我们的结果进一步强调了通过定量检验有关牙齿形状变异的假设，利用 EDJ 形状的三维几何形态测量分析来更好地为化石灵长类的α分类学提供信息的潜力。
