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.
