Atunāntakya (Atunantakya) is mentioned in Brahmāṇḍapurāṇa (Brahmandapurana) as a sage belonging to the Caraka (Charaka) branch of Kṛṣṇa-Yajurveda (Krishna-Yajurveda; Black-Yajurveda). 

Brahmāṇḍapurāṇa (Maharṣi)(1.33.15)