Ilango Adigal refers to the sage of the Pothiyil Hills, but never even mentions the name of Bharatha-Muni, even though his 'Arangetru-k-Kathai' leads us to suppose that he must have been familiar with the subject-matter of Bharata's Natya Sastra. And he makes Madhavi dance some of the minor dramatic forms coming under the category of 'Nritya,' without using either that word or 'Natya,' but introducing instead the ambiguous term 'Nataka.' Even among the eleven 'Adals' rendered by his danseuse heroine Madhavi, many are foreign to the 'Natyasastra.' While Bharata's treatise refers but casually to the existence of eighteen minor dramatic forms, (uparupakas), Ilango Adigal's eleven adals seen to have been actual living folk dances of his time.
('The dance forms of the early Tamils' by V Ramasubramaniam (Aundy).

Srihastamukhtavali by Subankara deals with hastas and mudras and is believed to have been written in Sanskrit with Assamese rendering around 16th century. The Sattra tradition refers to this as well as Natya Sastra, Abhinaya Darpana and Sangita Ratnakara. Subankara has also authored Sangitadamodara, which contains chapters on music.

Nanga was a common name given to danseuses those days in Kerala. Ar was added to give respect, so it became Nangar+Ar = Nangayar which is how the respected temple dancers were called then. Later on, the name changed to Nangiar.
(Nirmala Panikar, "Nangiar Koothu-a dance theater of the Nangiars of Kerala", Nartanam Vol Ii #3, July - Sept 2002, p 46)

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