Microstructural and Developmental Anatomy of the Dentition of Ardipithecus Ramidus

化石记录仍然是导致现代人类的解剖学适应的时间和顺序的唯一指南。 从1992年开始，代表已知最早的化石，也许是第一个，我们血统的物种在埃塞俄比亚阿法尔地区被发现。 这个新物种名为Ardipithecus ramidus，生活在440万年前的东非大裂谷北方的热带森林中。到1997年野外季节结束时，发现了代表数十人的化石，包括许多牙齿。 对A. ramidus牙齿从所有其他已知的原始人区分它展示了独特的宏观和微观结构的牙齿解剖。 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，牙齿的大小和形状的总体变化也提供了对其功能的了解。 这项研究将探索牙齿解剖在Ardipithecus ramidus，其他早期原始人，现存的猿，和现代人类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.