Great looking Bone Bead Gator. Are the vetebrae drilled as well? I have found a few of those on sites here that were polished and drilled and used as Beads.
If you mean the vertebrea.. these are shark..they are not bone they are a hard cartilage they grow in layers of rings and have a shape that is naturaly thinner in the middle so when ground down they get that groove effect. some belive them to be earspools "plugs" others beads.this website has them under bone and shell orniments listed as earspools. www.aboriginalantiquies.com
These are unaltered. Those natural notches in them go pretty deep so they had to start out with a pretty large one to work it down until it was smooth and still have a decent size left. I find alot of shell beads and drilled shark vertebrea that are not taken down like the ones above. I have found only five of those..I personally think they were earspools. The holes on that type show no sign of ever being strung through the holes.
I was talking about the ears pool groove on the outer portion. When you said ears pool, that answered it. I was thinking they were shell. Instead shark bone. Like a larger version of the round bone in a can of salmon. Cool!!