... The dates assigned to their epoch vary from the beginning of the seventh to the middle of the sixth century B.C.; but it is the more reasonable to place them, with Brunn, at the close of this period, without supposing that there were two masters by the name of Theodoros, a father and a son.  The innovation probably began with the solid casting of smaller works, but whether Rhoicos and Theodoros were limited to this is at least doubtful. (Reber)