I'm thinking "die gouge". A clash mark that deep should show some other design elements...I would think.
Looks to be the result of a clashed die. This is opposite E PLURIBUS UNUM and it is not uncommon to find traces of the motto in front of the Native American's face almost in the form of a mask.
The motto would be under his chin. However, it could be a die clash with the raised bone half way up the back leg. That would be the right size and placement.
I'm not an error guy but it seems to me the characteristics of such would manifest on a coin Design devices incused. Fields raised.
Hi, As i read, seem to be "two feathers variety (FS...)". It is an interesting coin in good condition. Thank you! CDNum.