From X/Twitter
gunagarbhah:What is the earliest textual/iconographic depiction of dakShiNAmUrti/antecedents of this form of shiva?
blog_supplement:the term devasya dakShiNamurteH is very old and seen in the sutra texts of the pAshupata-s. This is generally taken to mean the southern side of the li~Nga or image: i.g aghora. choLa images of classical dakShiNAmUrti appear much later
gunagarbhah:The appearance of the mantras of classical dakShiNAmurti:-When do they first appear? (And yes,the earlier references I found seemed more like references to aghora).
blog_supplement:not so simple: he appears earliest TMK as a narrator in the unmattabhairava-tantra, a tradition later continued into shrIkula i.e. dakShinAmUrti-saMhitA. That implies that he existed earlier than unmattabhairava as a deity who was worshipped. Various saiddhAntika texts explicitly mention his installation like kAmika and kAlottara. However, I think the most primitive form of the mantra is that from lakShmaNa-deshikendra’s shAradA-tilaka. This I think is drawn from “para”-netra-like source which might be at least as old as the netra or some old bhUta texts…the 36 syllabled one beginning with OM hrIM… and ending with rudrAya shambhave hrIM OM.
padmavajra 