Microstructural and Developmental Anatomy of the Dentition of Ardipithecus Ramidus

化石记录仍然是解释导致现代人类进化的解剖学适应的时间和顺序的唯一指南。从1992年开始，在埃塞俄比亚的阿法尔地区发现了最早的化石，也许是人类血统的第一个物种。这个新物种被命名为地猿，生活在440万年前东非裂谷北部的热带森林里。到1997年野外季节结束时，发现了几十具化石遗骸，其中包括许多牙齿。初步分析表明，南方古猿的牙齿通过独特的大体和微观结构解剖结构与所有其他已知的原始人区分开来。在很大程度上，由于我们对牙齿组织的生长和发育有了更好的了解，我们现在可以从这些牙齿和面部遗骸中，以一定的保真度重建牙齿、面部和躯体生长的时间、性质和持续时间。此外，牙齿大小和形状的大体变化也有助于了解它们的功能。这项研究将探索地猿分支种、其他早期原始人、现存猿类和现代人类的牙齿解剖结构，使用各种方法来阐明我们最早的祖先的适应、生长和进化。

The fossil record is still the only guide to the timing and sequence of anatomical adaptations that resulted in modern humans. Beginning in 1992, fossils representing the earliest known, and perhaps first, species of our lineage were recovered from the Afar region of Ethiopia. This new species, named Ardipithecus ramidus, lived 4.4 million years ago in the tropical forests of the northern East African Rift. By the end of the 1997 field season, fossilized remains representing dozens of individuals were found including many teeth. Preliminary analyses of A. ramidus teeth distinguish it from all other known hominids by demonstrating unique gross and microstructural dental anatomy. Due in large part to our better understanding of the growth and development of dental tissues, we can now reconstruct with some fidelity the timing, nature, and duration of dental, facial, and somatic growth from these dental and facial remains. In addition, gross changes in the size and shape of the teeth also provide insight into their function. This study will explore the dental anatomy in Ardipithecus ramidus, other early hominids, extant apes, and modern humans using a variety of approaches to shed light on the adaptations, growth, and evolution of our earliest ancestor.