In hopes of identifying this coin found years ago I emailed Kevin Barry,a dealer in ancient coins and sent him a pic of my find.I explained that I had found this coin on a beach near the town of Trinidad and thought it was Roman.I told him that Spanish explorers had sailed through this area back in the 1700's and had possibly landed at Trinidad.(not sure of this)
This is what he had to say..." Your coin is definitely Roman.The denomination is generically known as AE3/4.I cant tell the emperor, but judging by the style it would have been some time in the 300-400 AD range. Fragmentary historical evidence has shown that some Spanish ship captains carried Roman coins . Particularly from the era of your coin or later.The reasoning has been that the coins are from post-Christian conversion emperors and were carried as a sign of their own faith."
So,I cant prove how or when this coin was ever lost, but it sure is an interesting theory.It will remain a mystery forever.