Coywolf perhaps? Never seen a coyote that dark, and I've shot a bunch in IL, mostly while hunting pheasants.
Actually had a setter point one once; thought it was a rooster stuck in some heavy brush beaten down by a snow drift. Out popped a fair size dog. I shot with my 20g just behind its noggin'. Shot never even left the shot cup. Damend thing did a somersault and was deader than a stone.
My nephew may be the luckiest kid ever. Last year, second day rifle season a black one came out and he killed it. 3 minutes later another black one came out and he killed it. 5 minutes later and us still celebrating, an 8pt walks out and he killed it lol. One of the best hunts of my life.