Sacrum a lateral surface. The base of the sacrum, which is broad and expanded, is directed upward and forward. On either side of the base is a large projection known as an ala of sacrum and these alae (wings) articulate with the sacroiliac joints. The alae support the psoas major muscles and the lumbosacral trunk which connects the lumbar plexus with the sacral plexus. In the articulated pelvis the alae are continuous with the iliac fossa. Each ala is slightly concave from side to side, and convex from the back and gives attachment to a few of the fibers of the
Ver sacrum of Indo-Iranian human and warrior gods with animal forms: among the Iranian god of victory "V(e)r(e)thragna" 's incarnations, seven are of animal form, including the bull, horse, boar and hawk, each of which is associated at one time or another with a "ver sacrum" and Roman army insignia. On the "recto" of coins from Campania appears a human character bearing over his head that of a boar, and on the "verso" the word "ROMA". German scholar C. Koch interprets this character as god Quirinus, since he identifies the boar, "aper", as the animal symbol of the god. Dumézil remarks that