This skull has a fully ossified neck, every vertebra fused into one continuous column of bone. While dramatic, this kind of fusion can happen for a few different reasons. Some possible conditions that may cause this are: ankylosing spondylitis, an inflammatory condition that causes the ligaments and joints of the spine to slowly turn to bone, creating what’s sometimes called a “bamboo spine.” Diffuse idiopathic skeletal hyperostosis (DISH), a condition where flowing sheets of new bone form along