This type exists in four different denominations:
http://numismatics.org/sco/results?q=fulltext%3Aradiate+AND+fulltext%3Abird+AND+authority_facet%3A%22Antiochos+IV.%22+AND+material_facet%3A%22Bronze%22+AND+mint_facet%3A%22Seleuceia+ad+Tigrim%22
With around 9 g yours seems to be a dichalcon: http://numismatics.org/sco/id/sc.1.1509
As you see there are some coins minted on a very similar flan as your coin.
Regards
Altamura
Yes, this group of Antiochos IV bronzes have been studied and written about extensively by Edward
Newell,
Schlosser, Hoover, and others. Unusual among
Seleukid bronzes, this small group of Antiochos IV (from 'Seleukia on Tigris') have obvious explicit value marks right there for everyone to see: A/X (one
chalkous), B/X (two), DELTA/X (four), and some believe there's a 'half' chalkon with no mark. Mark
symbols are behind the
portrait. All three sizes have the same high-relief
portrait style with long parallel crown radiations. The
reverse of all sizes is the seated figure with a little bird at its feet.
They define a
weight standard with (mean)
weights in almost perfect proportion to the marked values - about 4, 8, and 16 grams (for A, B, and D
types). At first glance Antiochos IV might have
had a bronze coinage scheme with 4 grams = one
chalkous but it doesn't
work for other groups of Antiochos IV bronzes.
The coin here has the B/X symbol so its
weight of 9gm is right. If someone finds others that look similar and weigh ~ 4gm then they're likely to have the A/X symbol instead. The scarcest one is the D/X and they're often pretty worn but you can
still tell which value by their
weight. They're all
scarce in really
sharp condition.
PtolemAE