ᴹ√TARAK root. “horn (of animals)”
The earliest manifestation of this root was unglossed ᴱ√TARA⁽²⁾ in the Qenya Lexicon of the 1910s with derivatives like ᴱQ. taru “horn” and ᴱQ. tarukko “bull” (QL/89). It was originally given as ᴱ√TAŘA “chevaux de frise [fortifications of wooden spikes]”, but that sense and associated derivatives (“hedge” words) were transferred to ᴱ√TAÐA; see that entry for details. As for ᴱ√TARA² “*horn”, it also had derivatives in the contemporaneous Gnomish Lexicon such as G. târ “a horn” and G. tarog “ox” (GL/69).
The root ᴹ√TARAK “horn (of animals)” appeared in The Etymologies of the 1930s with derivatives ᴹQ. tarka/N. tarag of the same meaning, but the Noldorin word was also used of mountains, as seen in the name N. Taragaer “Ruddihorn” (Ety/TARÁK). The latter was an early precursor to the name S. Caradhras “Redhorn” in Lord of the Rings drafts of the 1940s; Taragaer was eventually abandoned (RS/419, 433).
Neo-Eldarin: I would ignore this root for purposes of Neo-Eldarin, and stick with derivatives of √RAS.
References ✧ Ety/TARÁK; PE19/58
ᴱ√TARA² root. “*horn”
Reference ✧ QL/89 ✧ “‽”