Ushnisha

It is thought that the interpretation of the ushnisha as a supernatural cranial protuberance happened at a later date, as the representation of the topknot became more symbolic and its original meaning was lost.

The Sri Lankan Tamrashatiya school, which would later give rise to Theravada, portrayed him as bald and having an ushnisha extending into the sky, beyond the possibility of measurement.

[2] The Gandharan school of Buddhism, sometimes portrayed Śākyamuni sporting a cluster of long wavy hair or curls as a topknot concealing the ushnisha.

[3] The Mahāvastu (1.259f) and the Divyāvadāna, as well as the Theravadin Milindapañha, describe some marks of the cakravartin, an idealised world-ruler, as consisting of an uṣṇīṣa or turban, a parasol, a "horn jewel" or vajra, a whisk and sandals.

[4] The art of early Mahayana Buddhism in Mathura presents bodhisattvas in a form called uṣṇīṣin "wearing a turban/hair binding", along with mudras that represent the nonviolent rule of a cakracartin.

[4] A bull figurine excavated from Lakhan-jo-Daro from the Bronze Age Indus Valley Civilization has a similar ushnisha-like knob above its head.

When the light that issues forth from a Buddha’s mouth returns to his uṣṇīṣa, it is a sign that he will give a prophecy of the eventual Buddhahood of someone in the audience.