Falk Dean, Clarke Ron
Department of Anthropology, Florida State University, Tallahassee, FL 32306-7772, USA.
Am J Phys Anthropol. 2007 Dec;134(4):529-34. doi: 10.1002/ajpa.20697.
Earlier reconstructions of the Taung endocast, from the juvenile type specimen for Australopithecus africanus, were achieved without benefit of the advanced computer technology that is available today and before morphological differences were identified that distinguish endocasts of Paranthropus from those of A. africanus. Here, we reconstruct and measure a relatively complete virtual endocast of Taung and provide a new cranial capacity estimate of 382 cm(3) and a projected adult capacity of 406 cm(3), which are smaller than previous estimates. Linear measurements and ratios were also obtained from an endocast of Sts 5 and five Paranthropus endocasts and compared with those of Taung. A number of previously unrecognized foramina, processes, and canals are identified in the bony material that adheres to the base of the Taung endocast. The newly reconstructed virtual endocast of Taung displays a number of shape features that sort it more closely with gracile than robust australopithecines, including squared-off frontal lobes in dorsal view, and the shape of the tips of its temporal poles. The Taung endocast also shares some features with Paranthropus endocasts, while other characteristics such as small temporal lobes may be due to its juvenile status. Just how much of Taung's unique morphology is due to its juvenile status may eventually be clarified by comparing its endocast with those from other juvenile australopithecines such as the 3.3-million-year-old juvenile from Dikika, Ethiopia.
早期对汤恩幼儿头骨化石内模的重建,是根据南方古猿非洲种的幼年类型标本完成的,当时还没有如今可用的先进计算机技术,而且在区分傍人属和非洲种的内模形态差异被识别出来之前。在此,我们重建并测量了一个相对完整的汤恩幼儿头骨化石虚拟内模,得出其新的脑容量估计值为382立方厘米,预计成年后的脑容量为406立方厘米,这比之前的估计值要小。还从斯泰克方丹5号标本的内模和五个傍人属的内模上获取了线性测量数据和比例,并与汤恩幼儿头骨化石内模的数据进行了比较。在附着于汤恩幼儿头骨化石内模底部的骨质材料中发现了一些以前未被识别的孔、突起和管道。新重建的汤恩幼儿头骨化石虚拟内模显示出一些形状特征,这些特征使其与纤细型南方古猿而非粗壮型南方古猿的关系更为密切,包括在背视图中呈方形的额叶,以及颞极尖端的形状。汤恩幼儿头骨化石内模也与傍人属的内模有一些共同特征,而其他特征,如颞叶较小,可能是由于其幼年状态。通过将汤恩幼儿头骨化石内模与其他幼年南方古猿的内模,如来自埃塞俄比亚迪基卡的330万年前的幼年个体的内模进行比较,或许最终可以弄清楚汤恩幼儿头骨化石独特形态中有多少是由于其幼年状态造成的。