In the months before birth, these vertebrae grow together into one bone that forms the base of the spine and the center of the pelvis. Description from cedars-sinai.edu. I searched for this on bing.com/images
Sacrum - the holy bone
3d rendered illustration of the female sacrum bone (Misc)
I like this picture so much. Because I think horses are beautiful animals.
Finnhorse:country of origin - Finland | average height ca. 155 cm (under 147 cm for pony type) | colours - predominantly chestnut, bay/brown, black, rarely dilutes (dun, cream, silver), grey, pinto patterns (sabino, splash white)