Chinese paleobotanical researchers have found plant fossils from 15 million years ago at an altitude of 5,800 meters on Mt. Qomolangma during a scientific expedition to the Qinghai-Tibet Plateau. According to the Chinese Academy of Sciences researchers, these fossils were once alpine oak leaves and tubers of equisetum, which is a plant similar to ferns. These plants cannot grow at such high altitudes and their discovery helps understand the history of land shifts and the evolution of plant diversity around Qomolangma, the highest peak in the world.