Are there prehistoric/ancient symbols that I could use for tattoo purposes?

I am planning for a new tattoo and want one that means something to me. I would like a symbol for mother or woman...along those lines. However, I am an anthropology major and would really like to find some type of ancient symbol to use..that way incorporating my educational interests. I have been looking for some type of myan or incan design...or even something in my area of interest (prehistory) would be great. I'm a female in my late 20s....looking to put the tattoo between my shoulder blades. Any help guys???