Beynon A D, Dean M C, Leakey M G, Reid D J, Walker A
Department of Oral Biology, Dental School, University of Newcastle upon Tyne, U.K.
J Hum Evol. 1998 Aug;35(2):163-209. doi: 10.1006/jhev.1998.0230.
Eighteen histological sections were prepared from eleven teeth attributed to Proconsul heseloni and two molar teeth attributed to Proconsul nyanzae. Measurements of spacings and counts of daily incremental markings in both enamel and dentine were possible in the majority of these tooth sections. Measurements of the spacings and angles to the enamel dentine junction (EDJ) of regular striae of Retzius and of equivalent markings in dentine were also made. In addition to these measurements, counts of perikymata were made on replicas of all other Proconsul teeth housed in the National Museum of Kenya, Nairobi, that preserved good perikymata on any aspect of their tooth surface. The sequence of crown formation in Proconsul and the crown formation times of the enamel and dentine were estimated from these data. In addition, the rates of root extension were estimated using the formula derived for this purpose by Shellis (Archs. oral Biol. 29, 697-705, 1984) and estimates of the total period of root formation subsequently made for premolar and molar teeth based on measurements of root length. A composite chart of dental development for P. heseloni is presented which suggests M3 root completion was between six and seven years of age. In general Proconsul molar teeth have high stria angles to the EDJ, a high ratio of enamel formed with respect of dentine formed at the same time, median values of rates of enamel formation close to the EDJ in excess of 4 microns per day and the occasional presence of "S-shaped" striae in the lateral enamel. There is no evidence to suggest that Proconsul from Rusinga Island, Kenya, had relatively thin enamel on molar or premolar teeth. When all of these data are considered in a comparative context, Proconsul emerges overall as hominoid-like in its enamel and dentine microstructure and as most similar to Pongo but with some features shared with Pan and Homo. Similar data for other Miocene primates will have considerable bearing on how these data are interpreted. These new data on dental microanatomy and on dental development in Proconsul make a further contribution to our understanding of the total morphological picture of this early Miocene primate.
从11颗属于赫氏原康修尔猿（Proconsul heseloni）的牙齿和2颗属于尼安萨原康修尔猿（Proconsul nyanzae）的磨牙制备了18个组织切片。在这些牙齿切片中的大多数中，可以测量釉质和牙本质中的间距并计算每日增量标记。还测量了芮氏线（Retzius striae）的间距以及与釉质牙本质界（EDJ）的角度，以及牙本质中相应标记的间距和角度。除了这些测量之外，还对内罗毕肯尼亚国家博物馆收藏的所有其他原康修尔猿牙齿的复制品进行了釉小皮计数，这些牙齿在其牙齿表面的任何部位都保留了良好的釉小皮。根据这些数据估计了原康修尔猿的牙冠形成顺序以及釉质和牙本质的牙冠形成时间。此外，使用Shellis为此目的推导的公式（《口腔生物学文献》29卷，697 - 705页，1984年）估计牙根延伸速率，并随后根据牙根长度测量对前磨牙和磨牙的牙根形成总周期进行估计。给出了一张赫氏原康修尔猿牙齿发育的综合图表，表明M3牙根完成时间在6至7岁之间。一般来说，原康修尔猿的磨牙与釉质牙本质界的条纹角度较高，同时形成的釉质与牙本质的比例较高，靠近釉质牙本质界的釉质形成速率中值超过每天4微米，并且在外侧釉质中偶尔会出现“S形”条纹。没有证据表明来自肯尼亚鲁辛加岛的原康修尔猿的磨牙或前磨牙的釉质相对较薄。当在比较的背景下考虑所有这些数据时，原康修尔猿在其釉质和牙本质微观结构方面总体上呈现出类人猿的特征，并且与猩猩最为相似，但也具有一些与黑猩猩和人类共有的特征。其他中新世灵长类动物的类似数据将对这些数据的解释有很大影响。这些关于原康修尔猿牙齿微观解剖和牙齿发育的新数据为我们对这种早中新世灵长类动物的整体形态图景的理解做出了进一步贡献。
