Évolution du chondrocrâne et de la face des grands anthropoïdes miocènes jusqu'à Homo sapiens, continuités et discontinuités

The chondocranium forms the base of the embryonic mammal cranium, with three cartilaginous nucleuses, the basi-ethmoid, the basi-sphenoid and the basi-occipital, all in a same alignment. They are differently aligned at birth, with a verticalization of the facial pole towards the occipital pole. The origin of this verticalization is the rotation of the basi-sphenoid, consequence of the rolling up of the underlying neural tube. The hominids and their descendants present a more important rotation than the living and fossil apes and, for the first time, is permanent from child to adult. Their apparition is inscribed in a process perceivable when one considers time at a large scale: continuous but presenting discontinuous effects.