The ape skull pronounced ridges on the surface of the skull. what are they for?

Question

. .pls help me.

Answer 1

There are probably two ridges which caught your attention on the ape skull.  The one which runs front to back, along the top of the skull is the sagittal crest, and serves as an attachment for the mastoid muscle which moves the jaw to chew.  The crest near the back of the skull, running side to side along the top is the nuchal crest, which allows the muscles of the neck to hold the head up.

Humans don't have much need for powerful chewing so we don't have a sagittal crest.  Our heads are also balanced on top of our heads rather than projecting forward, which limits the need for a nuchal crest.

Answer 2

The previous answers are correct.  The ridges are where the jaw muscles attach to the skull.  

Answer 3

that's something I'd have to chew on for a while....

Answer 4

most pronounced ridges on bones are for muscle attachments. where are the ridges that you refer to at?