There are four types of pelvic shapes. They are the gynecoid pelvis, android pelvis, anthropoid pelvis and the platypelloid pelvis.

This pelvis shape is described as "flat." The opening in the middle is not an open circle (gynecoid shape, most common) but more like a compressed oval shape. Woman with this type of pelvis are not able to easily have a vaginal birth. Less than 3% of all women have this pelvis shape.

No fish do not have a pelvis. Most fish do have bones, just not a pelvis.

density of the bones . shape of the cavity ,