The closest living relatives of humans, the great apes and especially gorillas or chimpanzees, have a very pronounced supraorbital ridge, which has also been called a frontal torus, [4] while in modern humans and orangutans, it is relatively reduced.

2017年4月20日 · The supraorbital torus (or brow ridge) is a very distinctive morphological trait in most of our hominin ancestors. What purpose does this feature serve? A few hypotheses around this topic are: Dissipation of heavy chewing forces, produced by the jaw muscles and transmitted around the nose and the eye sockets.

browridge, bony ridge over the eye sockets (orbits). Browridges are massive in gorillas and chimpanzees and are also well developed in extinct hominids. They are more prominent in males than in females. Browridges may have served as buttresses against the stress exerted by jaw muscles or as protection for the eyes.

Orangutans possess a supraorbital rim (a thin, non-projecting ridge across the orbits) rather than a torus, which may be a function of the airorynchy (backwards rotation of the face towards the neurocranium) that characterizes these apes.

It has been well established that primates with more retracted faces have smaller, shorter browridges with steeper frontal squamae, reflecting the supraorbital region's role to integrate spatially the upper face and the neurocranium (see ref. 14); linear measurements of facial retraction explain ≈80% of browridge length and frontal angle ...

The extant species of Pan, like other extant apes, are distinguished by their pronounced supraorbital tori and long projecting lower faces that house relatively larger anterior teeth (i.e. incisors and canines) than posterior teeth (i.e. premolars and molars).

2018年4月9日 · We propose that conversion of the large browridges of our immediate ancestors to a more vertical frontal bone in modern humans allowed highly mobile eyebrows to display subtle affiliative emotions.

2015年10月19日 · The supraorbital torus is found only in some genera of the primate order. Because no muscles of consequence attach directly to it, it has been considered nonfunctional. However, invitro strain-gauge experiments demonstrate that when the anterior teeth are loaded, the supraorbital region acts as a bent beam, pulled downward on each end by ...

The bridge model of the supraorbital torus, as presented by Shea and others such as Moss and Young (1960), is an inter-esting one because it is partially explanatory (see my article and also Russell 1983). In the bridge model, the supraorbital torus fills in any spatial gap which may occur between the orbital

The structural significance of the hominid supraorbital torus and its morphological variation have always been a controversial topic in physical anthropology. Understanding the function of browridge variation in living and fossil human populations is relevant to …