Depends on the size of the tusk. Before doing the pic, did some googling. Some mammoth tusks were relatively small (akin to elephant tusks), while others looked like they could have been over 10' long. Also depends on what form the Thoti-Eannorean language took. Many early languages were pictographic or symbolic in nature (i.e., cuneiform, hieroglyphs, etc.), and not necessarily phonetic. You could pack a lot of meaning into very few symbols.