Parker suggests Kleitarchos' use of three late sources, Timaios (see other threads for that argument) Berossos and Hieronymos. Taking the Berossos argument first I agree that Diodorus II 10 is largely Kleitarchos interjected into a surrounding matrix of Ktesias but the big mistake is to assume that the facts therein stem from Berossos; Kleitarchos actuall tells us on whom his assertions are based...'those who later crossed to Asia with Alexander' now, Berossos does not belong to this group. All other argumentation is of the order we love but is bad practice, towhit trying to compare two non-extant authors. I must confess that it was only on re-reading the paper this morning that the solution struck me and it is a familial trait to 'correct' Ktesias, Plutarch's 'Life of Artaxerxes' frequently puts information from Dinon against that of Ktesias (Plutarch prefers Ktesias). Berossos can be dropped too, then.
The argument for his use of Hieronymos is equally weak, depending on the facts that Megasthenes is reported to have given the width of the Ganges as 100 stadia, Hieronymos as 30 and Kleitarchos as 32 it is then supposed that Hieronymos has corrected Megasthenes and Kleitarchos tweaked Hieronymos; it is just as likely that Kleitarchos, who does seem to have used Megasthenes, corrected him and that Hieronymos then gave a round number; again it is possible that the number reported for Megasthenes is corrupt, numbers being quite liable to corruption ( this is certainly so in Curtius but I am not sure about Strabo so this is a weak option).
Once these authors are out of the equation an early third century date is very possible.Parker himself doubts a date later than the mid third is likely. Also the papyrus is in chronological order and Kleitarchos follows immediately on Chares (and before Hieronymos) I have still to work out the whole list, but soon, nephew and booze allowing

No argument is going to be conclusive but what abot those pesky Thessalians?
