It just so happens that recently I came across very similar arrowheads in the official publication of Nemrud Dag, Donald H. Sanders ed., Nemrud Daği. The Hierothesion of Antiochus I of Commagene (Winona Lake: Eisenbrauns, 1996), 2 volumes. Here is a photograph of the different types found:
http://antiquemilitaryhistory.com/images/arrowheads.jpgBecause of the chronology of the site at Nemrud Dağ, these can be dated to the Hellenistic period, but only one example was stratified and can be identified as late Hellenistic (n. 612 above). Apparently, similar arrowheads have been found at Arsameia-on-the-Nymphaios, also Hellenistic in date, and published in Friedrich Karl Dörner, Theresa Goell, Arsameia am Nymphaios, vol. 2. Das Hierothesion des Königs Mithradates I. Kallinikos von Kommagene nach den Ausgrabungen von 1963 bis 1967 (Berlin: Gebr. Mann, 1963), 275-81. Enough arrowheads were found at Nemrud Dağ that the excavators state that the full development of this type can be traced. The earliest form is n. 612, and this later changed into n. 614, similar example of which has been found at Kusura. The latest form is shown in nn. 615-7, which is paralleled by an example from Khorsabad. The excavators suggest that this may have been a particularly Commagenian style of arrowhead. Hope this helps!
