The divorce of The Black Keys' Dan Auerbach and his wife cost $5 million and Bob Dylan's hair.

TMZ obtained the court documents that revealed the odd item back in August.  But, at the time, we did not know what that actually meant.

As it turns out, "Bob Dylan's Hair" is not actually Bob Dylan's hair.  Auerbach tells TMZ, "It wasn't a lock of Bob Dylan's hair.  You know that famous old poster of Bob Dylan that's multiple colors, psychedelic, with the big afro?  We just labeled that 'Bob Dylan's hair.'"

See the a copy of the poster here

Auerbach added that he received a text from Bob Dylan's son saying, "If you really need a lock of his hair, I can probably get it for you."