Turtles in Carnuntum - The journey of a coin from Greece to roman Carnuntum

Near the Danube, 30 miles east of Vienna / Austria, there is a historically significant site: Carnuntum, a former roman military camp which housed two legions. At the end of the second century AD, Carnuntum was the headquarters of Northern Pannonia (Pannonia Superior). It was mainly to protect the Roman Empire from the Germanic 'Marcomani' invaders. Marcus Aurelius spent his final twelve years (168 - 180 AD) in Carnuntum, where he died at the age of 59.

6 BC	The first military camp is established.
35 - 40	The legio XV Apollinaris builds a camp.
117 - 138	Hadrian bestows Carnuntum the freedom of the city.
171 - 173	Headquarters of M. Aurel for fighting against the Germans.
9. April 193	Septimius Severus is proclaimed as the new emperor. Carnuntum gets the colonial status (Colonia Septimia Aurelia Antoniniana Carnuntum).
11. Nov 308	Diocletian convokes a imperial conference in Carnuntum.
400 +	The romans depart and leave.

A friend and metal detectorist in Carnuntum recently found a rather oval piece of silver. He was not sure what it was, some suggested that it is only a piece of silver lost by a jeweler, others said it is a silver stater from Aigina.

The island-state of Aigina, situated between Attica and the coastline of Argolis (Peloponnesus), was probably the first place in European Greece to mint coins. From Aigina the knowledge and practice of minting coins quickly spread

to other areas of Greece, like Athens, Corinth, Euboia and other important cities.

Look at the picture on the right for an example of a coin of Aigina. Obverse: smooth-shelled turtle Reverse: Incuse square,divided irregulary Minted: 485 - 480 BC In general these coins were minted from 550 - 480 BC. Now it is proof that it is a silver stater of Aigina found in Carnuntum.
This is the coin found in Carnuntum. The very interesting fact is that it was found on a field among mostly 3rd and 4th century AD coins. Even in the worst case (i.e. the coin came to Carnuntum when the first military camp was established in 6 BC) there are 500 years between the mint and the time when it was lost/buried/hidden in the soil in Carnuntum.
This leads us to 3 theories why this coin came to Carnuntum centuries later. Decide yourself in which you will believe. 1. The coin was found by a roman in greece and was brought to Carnuntum in the 3rd or 4th century. 2. The coin was part of an ancient heritage or the coin was simply passed along the generations as an example of the first coins ever or as an unusual coin.	3. The coin was part of an ancient coin collection created by a trader, who collected unusual coins which passed his shop. A similar situation happened in Caesarea Maritima / Israel, where a hoard of unusual coins was found in a 4th century AD warehouse. A Ptolemaic bronze of the 3rd century BC to an AE 1 of Julian II. was found. None of them typical of 4th century circulating coinage of the region in Israel. It certainly looked like someone was setting aside any unusual coins that came his way.
These are the most probable theories for me. Decide which theory you like to believe in. In any case the coin came to Carnuntum at least 500 years after it was minted (around the birth of Jesus), most probable 600 to 850 years later (100 - 350 AD) and maximum 900 years later when the romans left Carnuntum (400 AD).