The simian shelf is a bony thickening on the front of the ape mandible. Its function is to reinforce the jaw, though it also has the effect of considerably reducing the movement of the tongue by restricting the area available for muscles.
Humans are the only primates to have protruding chins, though some fossils of early humans show evidence of a simian shelf.
Famous quotes containing the words simian and/or shelf:
“Time points the simian camera in the head
Upon confusion to be seen and seen.”
—Philip Larkin (1922–1986)
“Give him the darkest inch your shelf allows,
Hide him in lonely garrets, if you will,—
But his hard, human pulse is throbbing still
With the sure strength that fearless truth endows.”
—Edwin Arlington Robinson (1869–1935)