Le Cabec Adeline, Dean M Christopher, Begun David R
Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, D-04103, Leipzig, Germany; Beamline ID19, Structure of Materials, ESRF - The European Synchrotron, 71, avenue des Martyrs, CS 40220, F-38043, Grenoble, Cédex 9, France.
Department of Cell and Developmental Biology, University College London, Gower Street, London, WC1E 6BT, UK.
J Hum Evol. 2017 Jul;108:161-175. doi: 10.1016/j.jhevol.2017.03.007. Epub 2017 May 23.
The chronology of dental development and life history of primitive catarrhines provides a crucial comparative framework for understanding the evolution of hominoids and Old World monkeys. Among the extinct groups of catarrhines are the pliopithecoids, with no known descendants. Anapithecus hernyaki is a medium-size stem catarrhine known from Austria, Hungary and Germany around 10 Ma, and represents a terminal lineage of a clade predating the divergence of hominoids and cercopithecoids, probably more than 30 Ma. In a previous study, Anapithecus was characterized as having fast dental development. Here, we used non-destructive propagation phase contrast synchrotron micro-tomography to image several dental microstructural features in the mixed mandibular dentition of RUD 9, the holotype of A. hernyaki. We estimate its age at death to be 1.9 years and describe the pattern, sequence and timing of tooth mineralization. Our results do not support any simplistic correlation between body mass and striae periodicity, since RUD 9 has a 3-day periodicity, which was previously thought unlikely based on body mass estimates in Anapithecus. We demonstrate that the teeth in RUD 9 grew even faster and initiated even earlier in development than suggested previously. Permanent first molars and the canine initiated 49 and 38 days prenatally, respectively. These results contribute to a better understanding of dental development in Anapithecus and may provide a window into the dental development of the last common ancestor of hominoids and cercopithecoids.
原始狭鼻猴类的牙齿发育年表和生活史为理解类人猿和旧世界猴的进化提供了一个至关重要的比较框架。在已灭绝的狭鼻猴类群体中，有猿猴超科，它们没有已知的后代。赫氏阿纳皮猴是一种中等体型的狭鼻猴类祖先，在约1000万年前生活在奥地利、匈牙利和德国，代表了一个在类人猿和猕猴科动物分化之前的进化支系的末端分支，可能超过3000万年前。在之前的一项研究中，阿纳皮猴被描述为具有快速的牙齿发育。在这里，我们使用非破坏性传播相位对比同步加速器显微断层扫描技术对赫氏阿纳皮猴的模式标本RUD 9的混合下颌牙列中的几个牙齿微观结构特征进行成像。我们估计它的死亡年龄为1.9岁，并描述了牙齿矿化的模式、顺序和时间。我们的结果不支持体重与生长线周期之间存在任何简单的相关性，因为RUD 9的生长线周期为3天，而根据对阿纳皮猴体重的估计，之前认为这是不太可能的。我们证明，RUD 9中的牙齿生长速度甚至比之前认为的还要快，并且在发育中开始的时间更早。恒第一磨牙和犬齿分别在产前49天和38天开始发育。这些结果有助于更好地理解阿纳皮猴的牙齿发育，并可能为了解类人猿和猕猴科动物的最后共同祖先的牙齿发育提供一个窗口。
