There were many different schools of Buddhism travelling on the Silk Road. The Dharmaguptakas and the Sarvastivadins were two of the major Nikaya schools. These were both eventually displaced by the Mahayana, also known as "Great Vehicle". This movement of Buddhism first gained influence in the Khotan region. The Mahayana, which was more of a "pan-Buddhist movement" than a school of Buddhism, appears to have begun in northwestern India or Central Asia. It formed during the 1st century BCE and was small at first, and the origins of this "Greater Vehicle" are not fully clear. Some Mahayana scripts were found in northern Pakistan, but the main texts are still believed to have been composed in Central Asia along the Silk Road. These different schools and movements of Buddhism were a result of the diverse and complex influences and beliefs on the Silk Road. With the rise of Mahayana Buddhism, the initial direction of Buddhist development changed. This form of Buddhism highlighted, as stated by Xinru Liu, "the elusiveness of physical reality, including material wealth." It also stressed getting rid of material desire to a certain point; this was often difficult for followers to understand.