This coin is from the "CA" series, generally thought to have been struck in Canusium(modern-day Canosa, Italy), circa 209-208 B.C.. Both the mintmark, CA, and and find evidence support Canusium as the mint but neither offer much historical context around the issue, but luckily the Romans left one very interesting clue for future numismatists. As far as I have seen, the triens denomination of the series always come overstruck on bronzes of Acarnania and Oeniadae, though few overstrikes are known to me within any of the other denominations so why would a series struck in Southeast Italy have so many known overstrikes on undertypes from far away across the Adriatic?
The answer is that Marcus Valerius Laevinus had earlier driven the Macedonians from this region and this issue from Canusium represents booty captured during this fighting and brought back with the fleet when M. Valerius landed in Southern Italy circa 210-209 B.C.. The trientes were simply overstruck likely because many of the captured coins were close enough to the necessary weight and the rest of the denominations were probably mostly struck on flans whose bronze came from melting down and recasting of the captured booty. Since this issue contains no precious metal coinage, I think it likely that if any precious metal was captured it was either sent back to Rome or used by one of the other Roman field mints operating in Apulia.
Roman Republic Æ Sextans(16mm, 4.29g, 10h), anonymous("CA" series), 209-208 B.C., Canusium mint. Head of Mercury right; above, ••; to left, CA downwards / Prow right; above, ROMA; below, ••; to right, CA. Crawford 100/5; Russo RBW -; Sydenham 309f.