Bones with Vulture Shading

I was so happy with how well this turned out it inspired to create my Deviant Art account.
I got lucky how well this one turned out. Please don't let this first deviantion set the bar too high...

This was a project for class to practice continuous tone shading. Done on Strathmore paper with graphite pencils and a kneaded eraser. The object in the foreground was a small animal skull with a pair or two pronged antlers. Behind it is a wood cut sculpture of a vulture. Both were part of a larger still life set up for the class to draw. The exercise was to shade the objects and leave no sketch lines when finished.

I didn't spend enough time on the forehead of the skull because that's when I had to leave for my next class. And I see some other lines I would like to erase now that the image is so large, but in reality this picture is only 4"x5".