The Sthavira nikāya (Sanskrit "Sect of the Elders"; Chinese: 上座部; pinyin: Shàngzuò Bù; Vietnamese: Trưởng lão bộ) was one of the early Buddhist schools.
[4] The Tibetan historian Buton Rinchen Drub (1290–1364) wrote that the Mahāsāṃghikas used Prakrit, the Sarvāstivādins used Sanskrit, the Sthaviras used Paiśācī, and the Saṃmitīya used Apabhraṃśa.
[8] Starting with the Dīpavaṃsa chronicle in the 4th century, the Theravādins of the Mahāvihāra in Sri Lanka attempted to identify themselves with the original Sthavira sect.
[10] The Dīpavaṃsa chronicle lauds the Theravāda as a "great banyan" and dismissively portrays the other early Buddhist schools as thorns (kaṇṭaka).
[9] Dīpavaṃsa, 4.90–91 says: According to the Mahāvaṃsa, a Theravādin source, after the Second Council was closed those taking the side of junior monks did not accept the verdict but held an assembly of their own attended by ten thousand calling it a Mahasangiti (Great Convocation) from which the school derived its name Mahāsāṃghika.