Xu ChenXu CHEN, the former chairman of the International Sub-commission on Ordovician Stratigraphy (ISOS) and the chairman of the International Graptolite Working Group, and Academician of the Chinese Academy of Sciences. For his outstanding and profound wok on graptolite and Early Palaeozoic stratigraphy, he won the Charles University Gold Medal of Czech Republic in 1999, Lee Sikuang Geologist Award in 1999, and the National Award of Natural Sciences of China in 2008, among his most important awards. His paper on end-Ordovician mass extinction was awarded The Annual Best Paper of Journal of Paleontology in 2005 Read More Read Less