It was long considered conspecific with the European edible dormouse (G. glis) until a 2021 phylogenetic study supported it being a distinct species.

[1] It is thought to have diverged from G. glis during a fragmentation of the ancestral Glis population (likely triggered by the Messinian salinity crisis) during the late Miocene, about 5.74 million years ago.

[2][3] Significant genetic divergence also occurs within this species; populations from eastern Iran and western Iran display a deep divergence of about 1.19 million years ago.

[2] It is restricted to the Caspian Hyrcanian mixed forests ecoregion, which served as a likely refugium for it during the original range fragmentation of Glis.

It ranges from southernmost Azerbaijan to throughout most of Iran's Caspian Sea coast, and into Turkmenistan.