bone element replacement element replacement bone This class was introduced to be consistent with the ZFA hierarchy. The corresponding TAO term was obsoleted, and never introduced into VSAO. Note that VSAO does have replacement element. TAO:0001637 replacement bones Bone that forms as a replacement of another structural tissue.[TAO] ZFA:0001628 UBERON:0012075 Bone that forms as a replacement of another structural tissue. AAO:0010768