Examination of Dental Maturation in South African Australopithecines by Computed Tomography

Drs。Conroy和Vannier是将计算机断层扫描（CT）技术应用于古生物材料的先驱。在以前的国家科学基金会的支持下，他们已经证明了部分埋在沉积基质中的化石标本可以被分析。通过CT，粘连的材料实际上可以被剥离以显示下面的骨骼。此外，还可以检查骨骼的内部结构。这些结果使古生物学家和古人类学家能够解决新的问题。在这个项目中，Conroy博士和Vannier博士将继续他们对原始人类（人类）颅骨化石的研究。他们将前往南非，在那里发现了许多重要的标本，现在安置在那里并进行CT研究。结果以计算机形式存储，然后将在华盛顿大学进行分析。为了提供基线数据，还将研究现代标本的样本。该小组将特别关注牙齿和牙齿萌牙的阶段。通过这种方式，他们将试图确定个体死亡的年龄，并重建出牙的模式。这项研究之所以重要，有几个原因。首先，人类学家无法就非洲化石记录中有多少种不同的早期人类达成一致。通过比较许多化石的发育速度，这些分类可能会变得更加清楚。其次，人类学家争论不同的原始人在何种程度上更像人类或更像类人猿。在这项工作之前，证据仅限于视觉检查，注意到牙齿从下颌骨或上颌骨突出。由于CT技术允许人们检查未出牙的发育阶段，它提供了一个更灵敏的测量方法。最后，这项研究将为人类基本生物学特征的发展提供额外的见解。

Drs. Conroy and Vannier are pioneers in the application of computed tomographic (CT) techniques to paleontological materials. With previous NSF support, they have demonstrated that fossilized specimens still partially embedded in sedimentary matrix may be analyzed. With CT, the adhering material can, in effect, be stripped away to reveal the underlying bone. Also it is possible to examine the internal structure of the bone. These results have permitted paleontologists and paleoanthropologists to address new questions. In this project Dr. Conroy and Vannier will continue their study of fossil hominid (human) cranial remains. They will travel to South Africa, where many important specimens were found and are now housed and conduct CT studies. The results, stored in computerized form, will then be analyzed at Washington University. To provide baseline data, a sample of modern specimens will also be studied. In particular, the team will focus on the teeth and stages of dental eruption. In this way they will attempt to determine the age at which individuals died and to reconstruct the patterns of dental eruption. This research is important for several reasons. First, anthropologists cannot agree on how many different kinds of early humans are represented in the African fossil record. Through comparison of developmental rates in a number of fossils, these groupings may become more clear. Secondly, anthropologists argue about the extent to which different hominid species were, in their developmental rates, more human or more pongid (great ape) like. Until this work, the evidence has been limited to visual inspection which noted the teeth protruding from the mandible or maxilla. Because the CT technique allows one to examine the developmental stages of unerupted teeth, it offers a much more sensitive measure. Finally, this research will provide additional insight into the development of basic human biological characteristics.