Flashcards in Neandertal Anatomy Deck (11)
Neanderthals possess features that are not present in either modern humans or archaic Homo sapiens- such as Homo heridelbergensis.
Vault and cranium
The vault of the neandertal is low and long, its size and shape are quite different from that of Homo erectus. The maximum cranial breadth of the Neandertals is in the middle of the cranium whereas in H. sapians it's higher up up- closer to the mastoid process (behind the ears) and in H. erectus is the lowest.
Their cranium is larger than that of H. erectus or H. sapians.
In humans the occipital bone, at the back of the head where the muscles of the neck attach, is flat where as in neandertals it's smaller and bulges out like a bun. The mastoid process - bone behind the ear is smaller but the ridge of bone next to it, the juxtamastoid eminance is larger than the mastoid process.
Neandertals have a mid facial prognathism- The middle of the face around the nose projects anteriorly while the cheeks are placed far posteriorly. The face as the whole is rather tall, possibly due to the anterior position of the mid face and upper dentition. Neandertals have no development of a chin.
The semicircular canals of the inner ear anatomy assist in maintaining balance, but there are some anatomical differences. H. erectus and modern humans have the same structure, but Neandertals have a different structure.
The upper incisors of neandertals were more curved than those of modern humans and the build up of ridges of enamel give the tooth a shovel- shaped appearance. This shape is associated with greater resistance to wear. The lower forth premolar have extra sub cusps that modern humans lack. The molars had expanded pulp cavities and fused roots, called taurodontism. These teeth can sustain more wear because they maintainan a broader base for wear after the enamel has worn away.
Why do neandertals have large noses?
A popular idea is that the large noses warm the cold air before it reaches the brain and respiratory system. Although modern humans that live in cold environments have long narrow noses, that restrict cold airflow to the brain whereas board noses are more associated with tropically adapted peoples and facilitate heat dissipation.
Why do neandertals have facial prognathism?
Some suggest that the mid facial prognathism and the large nose that goes along with it, dissipate heavy bite loads on the anterior dentition. However, in other animals or hominids that have heavy bite loads the face is typically retracted, not prognthic. The facial muscles forces of Neandertals do not differ much form that of modern humans. As of now there is no explanation for the facial morphology of neandertals.
Postcranial skeleton of Neandertals
On average neandertals were shorter than modern humans, the chest was barrel shaped and the limbs- in particular the forearm and shin were short. These characteristics are consistent with a body trying to conserve heat in cold climates. The long bones are major joints are more robust than those of modern humans, these indicate a physically demanding lifestyle. The neandertal skeleton shows evidence of having very large and powerful muscles.
Differences of the pubic bone between modern humans and neandetals
The pubic bone forms the front part of the pelvis, the upper anterior part of the pubis- the superior pubic ramus- was longer and more gracile this is in direct opposition to the pattern established by the rest of the skeleton, this lengthened pelvis does not mean neandertals have a larger pelvic outlet. This suggests that larger pubic size is not related to either increased birth efficiency or increased gestation time. The broader pelvis may've been the neandertal way of increasing surface area to volume ratio to aid in heat retention.