Reading between lines : what can enamel tell us about human evolution

There has been much debate concerning the development of hominins over the years. The age at death of the first australopith ever discovered, the Taung child, was estimated to be around 6 years using modern human standards because the lower first molar was erupting. However, if we use chimpanzees as reference, the age at death is around 3 years. This fact denotes the incapacity of approaching age at deaths using any extant species as reference. Fortunately, the precise knowledge of the enamel histology allows to break this vicious circle and directly calculate enamel formation times and age at deaths. New sophisticated techniques are helping us to broaden our knowledge and comprehension of how our ancestors were biologically enlarging and modifying the pattern of their ontogenetic trajectories by the study of dental development. The hominins of the Atapuerca archaeo-palaeontological sites (Spain) are particularly relevant in this debate because they fill a 1 million year gap where the dental development is barely known.