Researchers led by Roy A. Wogelius at the University of Manchester have detected traces of copper and zinc in a preserved fossil of Confuciusornis sanctus using several synchrotron-based X-ray spectroscopies. Researchers concluded that the copper and zinc were formerly part of a dark organometallic pigment found in the bird's quills. The team mapped the distribution of dark eumelanin pigment in the ancient bird's plumage using the data. Scientists have been able to detect specific pigment chemicals from an ancient animal's soft tissue on a fossil for the first time. The new technique complements another recently developed strategy to infer color from the shapes of pigments left on fossils. Wogelius is developing the technique to study older fossils and is also trying to figure out what other information can be garnered from leftover metals in fossils. He also wants to use X-ray spectroscopy on fossils to understand the chemistry of extremely slow reactions.