Well, musick, according to M-W Collegiate, the word came from: Etymology: Middle English dozeine, from Middle French dozaine, from doze twelve, from Latin duodecim, from duo two + decem ten
How we came to measure out things that way, I don't know. I also don't know how something could have "an almost missing" claw . Could you 'splain, please? Hey--I just realized where the "duodecim"al system came from!