Ostur Spain - AE18 Circa 150-100 BC
3.79g
Obv: Acorn "[OS]TVR"
Rev: Two palm fronds
Burgos 1550v
As this coin is smaller than Burgos 1550 (21mm) and the weight is lower (vs. 7.5g or so), this seams to be an unpublished reduced denomination (1/2 the denomination?)