One punch-mark symbol (square divided into segments) / Blank, 7mmx5mm, 0.36 grams. Unknown Malwa mint (Vidisha?). Gupta/Hardaker 618 var (series VIII); MACW -; Pieper -.
The small copper punchmarks (of an average 2-mashaka weight) were probably derived from Gupta/Hardaker's Series VIII #618, with the crisscross punch from type 618 inspiring this type. They are They are found mostly in the Malwa region, the seat of the Sunga Kingdom, thus they are usually attributed to the Sungas. Considering that these must have been second generation derivations, they probably date to the later part of the Sunga rule.
The quality of post-Mauryan coins quickly deteriorated, and the latest bronze punchmarks were tiny and showed very crude small punchmarks. They likely date to the period of the late Sunga Empire. These coins are very poorly known - this type is not listed either in Mitchiner, Gupta/Hardaker or Mitchiner. These tiny coins are known mostly from a recent find.
The Shunga Empire was an ancient Indian dynasty from Magadha that controlled areas of the most of the northern Indian subcontinent from around 185 to 73 BCE. The dynasty was established by Pushyamitra, after taking the throne of the Maurya Empire.