Sacrum bodies are seen to be united at their circumferences by bone, wide intervals being left centrally, which, in the fresh state, are filled by the intervertebral discs. The dorsal surface of the sacrum is convex and narrower than the pelvic surface. In the middle line is the median sacral crest, surmounted by three or four tubercles—the rudimentary spinous processes of the upper three or four sacral vertebrae. On either side of the median sacral crest is a shallow sacral groove, which gives origin to the multifidus muscle. The floor of the groove is formed by the united laminae 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