Mandibles of Neandertals and modern humans

Many of the differences between Neandertals and modern humans can be found in the face and jaw. Neandertals had relatively tall faces, and substantial prognathism of the midface. To describe more fully: Neandertal faces were tall from the chin to the browridge, and they extended far forward relative to the ears.

These aspects of facial anatomy are reflected in the Neandertal mandible. The part of the mandible that includes the alveoli for the roots of the teeth is called the corpus. The corpus tends to be thicker and stronger in Neandertals than in most living people. It also tends to be taller, with a greater distance between the inferior border of the mandible and the teeth.

At the front of the mandible is the mandibular symphysis. In modern humans, there tends to be a projecting triangle of bone, which we call the chin, but in technical terms is known as the mental eminence. Few Neandertal fossils have a chin. Most, like earlier hominins, have a slightly receding mandibular symphysis.

The part of the mandible that stretches upward from the corpus to connect to the temporal bones is called the mandibular ramus. The shape of the Neandertal tooth rows is basically the same as in the human jaw. But the mandibular ramus is relatively more posterior, so that there is a gap between the third molar and the anterior border of the ramus. This gap is called a retromolar space, and it reflects the strong midfacial prognathism of the Neandertal skull.

What to do: This station has several Neandertal partial mandibles, from the site of Krapina, Croatia. There is one early modern human mandible from Skhul, in present-day Israel. These are comparable in age (Krapina is 120,000 years old, Skhul is around 100,000 years old). Compare these to the recent human mandibles at the station and consider how these Neandertals fit relative to human variation.