rib floating rib http://upload.wikimedia.org/wikipedia/commons/f/f7/Skeleton_woman_back.png free rib costae fluctuantes FMA:7595 We synonymize 'free rib' with 'floating rib' - this case it referes to caudal ribs, but you can have free ribs (i.e. non-attached ventrally) in other places . Should we just synonymize this with 'floating rib'? see Primate Anatomy: An Introduction by Friderun Ankel-Simons pg. 275 costae fluitantes EMAPA:37494 UBERON:0002239 vertebral rib costa fluitante MA:0001399 A rib that is not connected to sternum or sternal cartilage. uberon OpenCyc:Mx4rvaPCWZwpEbGdrcN5Y29ycA