My first thought was "WOW!" My second was -- how did he do this? It's too organic for computer, so I read the comments until I found that you used colored pencils. I find that they are an excellent way to get the tiny details in and get them right. You got them right. From what I've seen your rendition is as accurate as anything out there since this guy is still open to interpretation. It's better than most I've seen by the professional paleo-artists. Nice job!