Pelvis

The pelvis (pl. pelvises or pelves) is the bony structure located at the base of the spine (properly known as the caudal end). It is part of the appendicular skeleton. Each os coxae (hipbone) consists of three bones: the illium, ischium, and the pubis. The illium is the largest and upper most part, the ischium is the posterior-inferior (back-lower) part, and the pubis is the anterior (front) part of the hipbone. The two hipbones are joined anteriorly  at the symphysis pubis and posteriorly to the sacrum. The pelvis incorporates the socket portion of the hip joint for each leg (in bipeds) or hind leg (in quadrupeds). It forms the lower limb (or hind-limb) girdle of the skeleton.

Gender differences
There are four main types of pelvis
 * Infrapubic angle is greater than 90˚ in females and less than 90˚ in males
 * Pelvic inletin males is more heart-shaped, while in females it is more round or oval
 * Greater sciatic notch narrower in males
 * Acetabulum in males faces more laterally, while it faces more anteriorly in females
 * Sacrum more triangular in females
 * Gynaecoid
 * Normal female p elvis
 * Round with enlarged transverse diameter
 * Android
 * Normal male pelvis
 * Heart shaped
 * Anthropoid
 * Long anterior to posterior diameter
 * Platypelloid
 * Long transverse diameter