Abstract: Four dinosaur fossils from three counties of Chuxiong area were tested with synchrotron x-ray fluorescence microprobe. The tests provide images of nine metal elements（Ca, Mn, Fe, Cu, Ta, Zn, Rb, Sr and Y） within each microarea of 2 mm×2 mm on the fossil sections. Particularly, the images of Ta and Rb were obtained for the first time for dinosaur fossils. The results show that metal elements are heterogeneously distributed at least in the test areas. In detail, the distribution of Cu is similar with that of Ta. However, Ca is enveloped by Y at some area of dinosaur fossils, The work demonstrats that synchrotron light source x-ray fluorescence microprobe is powerful and valuable for studing dinosaur fossils in geology and paleontology.

Key words: dinosaur fossils, mapping metal elements, SR-XRF, dinosaur fossils, mapping metal elements