Most traditions of Buddhism claim that their practices go all the way back to the Buddha himself. When, in fact, many practices have evolved over the centuries to become what they are today. Most have come about because of syncretic mixing with indigenous cultural practices.
Tibetan Buddhism is heir to the shamanic traditions of Tibet, the Tantric movement in medieval India, and late Indian Buddhist scholasticism.
Zen and Chan Buddhism came about after mixing with Daoist and Confucian thought.
Theravada Buddhism, which claims orthodoxy, is actually heavily influenced by a 5th century monk named Buddhaghosa. And the modern Vipassana movement actually derives from a lay-Buddhist meditation movement that began in the last few centuries.
Still, all Buddhist traditions follow a common framework of teachings that can be traced to the historical Buddha (or, at the very least, the early Buddhist schools). That framework is the Four Noble Truths and the Eightfold Path, often subdivided into the three practices of Sila (ethics), Samadhi (meditative training), and Panna (insight or wisdom).