I scan all my state quarters for my wife. She collects the new releases as she encounters them. She brought this 2006D Nevada state quarter home and I snagged it for a Coin People post.

It has a die break that runs along the base of the bust at the high point and extends out in front of the bust. The most distinct section of the break makes it appear like a spiked bust. It is possible that it is a gouge produced by cleaning a clogged die with the cleaning tool gouging the recessed portion of the die extending out into the field. Absent an examination with a microscope, it looks like a break with the magnification available to me.

I found a second example of this or a similar die break in change today (maybe the batch made its way to my part of the California coast). The second example has circulated for a while, so most of the break along the edge of the bust is worn off. There is a significant break (wider than pictured above designer initials). The spike coming off the bust curves at the end.

I sent one like that to Trantor_3 a few weeks back, but it was a P not a D.