It is 520 million years old and it may be the ancestor of all vertebrates on Earth. Say hello to yunnanozoans!
Yunna-what? As reported by Qingyi Tian (Nanjing University, China) and colleagues in the journal Science, certain fossils from the Cambrian period have structures suggesting they may be the ancestors of all vertebrates on Earth. First discovered in the 1990s in China’s Yunnan province, the place of this fishlike fossil within the tree of life was long debated. Tian’s team points specifically to pharyngeal arches within the mouth and head of fossils, which were examined using sophisticated techniques: x-ray micro-tomography, scanning electron microscopy and energy dispersive spectrometry element mapping. The pharyngeal arches would later evolve into jaws and braincases.