What is the best setup to take skulls / bones pictures?

I need to take pictures of bones (about 40cm) for my study in anthropology but I have too much shadows under the bones, what is for you the best way to take this kind of pictures?

I have a DSLR Canon EOS 70D, Sigma f1.4 30mm and a Canon f4-5.6 55 – 250

I haven’t any lightbox, and only a Cobra flash.
Is 200€ budget enough to buy some kind of light stuff?

Thanks