Exclusion of my name as co author
We don't know the specific situation of the paper or your thesis, but as a general rule, you should be an author if (i) you participated in the intellectual development of the research in question, and (ii) you participated in the work that needed to be done.

So, if the paper is about determining the isotopic structure and age analysis of a bone that you collected and for which you had previously done archaeological analyses (i.e., the paper and your study look at different things), then you probably do not deserve to be an author because you only provided a bone, but did not participate in the research as reported on in the paper.

On the other hand, if the paper does not only do some isotope analysis, but also describes the archaeological setting as an important part of the paper (i.e., your work; rather than just quote your previous work to provide a setting for the paper), then you should be an author on the paper.

In the end, we cannot tell you whether or not you should have been an author because we don't know what exactly the paper contains, and how that relates to your work.