Sacrum lumbar vertebra, and its lower part with the coccyx (tailbone) via the sacral and coccygeal cornua. The sacrum has three different surfaces which are shaped to accommodate surrounding pelvic structures. Overall it is concave (curved upon itself). The base of the sacrum, the broadest and uppermost part, is tilted forward as the sacral promontory internally. The central part is curved outward toward the posterior, allowing greater room for the pelvic cavity. In all other quadrupedal vertebrates, the pelvic vertebrae undergo a similar developmental process to form a sacrum in the adult, even while the bony tail (caudal) vertebrae remain unfused.
Traditional Chinese medicines derived from the human body infectious disease is really not pertinent "because bone would be ineffective in the treatment of any infectious process." Prescription 52.28.1 (tr. Luo 2003: 4180-4181) "Tianlingaisan" "Powder of human Skull Top", which is said to be "good for killing worms in a consumptive disease", mentions seeing a "chuanshi". First, take "one piece of human skull top two fingers wide, simmer the drug with Tanxiang/sandalwood, then stir-fry with Su/butter. Then chant incantations." Fifteen herbal ingredients are added with the skull bone into a decoction, which will cause the patient to defecate "worms of strange shapes". Cooper & Sivin (tr. 1973: 250) translate