In the context of the Kurgan hypothesis, Graeco-Aryan is also known as "Late Proto-Indo-European" or "Late Indo-European" to suggest that Graeco-Aryan forms a dialect group, which corresponds to the latest stage of linguistic unity in the Indo-European homeland in the early part of the 3rd millennium BC.
By 2500 BC, Proto-Greek and Proto-Indo-Iranian had separated and moved respectively westward and eastward from the Pontic Steppe.
That would have occurred after early stages of Proto-Greek and Proto-Indo-Iranian had developed into separate dialects but before they ceased to be in geographic contact.
[citation needed] Evidence for the existence of a Graeco-Aryan subclade was given by Wolfram Euler's 1979 examination on shared features in Greek and Sanskrit nominal inflection.
[2] Graeco-Aryan is invoked in particular in studies of comparative mythology such as Martin Litchfield West (1999)[3] and Calvert Watkins (2001).