|I think this is improved on the original image, in my opinion.
Being darker, and filled with more shadow, lends itself well to the subject matter.
I still feel the skull on the orginal image is overexposed. By comparing your original to its workshop, the alteration in brightness is very visible.
I have played with the brightness and contrast of your original post, as suggested. I think I lost some details, but when I compare the two I think it improves on the darkness of the image. The shape of the skull is easier to distinguish in a darkened image. By that I mean the curves and details in the skulls design.
Do not worry too much about details in the surrounding grass and stones, though. It is the skull which is the subject of the image. Best to focus on getting the image right to show off the skull.