Galerix kostakii is a fossil erinaceid mammal from the early Miocene of Greece. It is known from the site of Karydia, assigned to the biostratigraphical zone MN 4; similar fossils have been found at an approximately contemporary Czech site and a slightly younger Greek site. With characters like the presence of a hypocone (fourth cusp) on the upper third premolar, the presence of a connection between the protocone and metaconule cusps on the second upper molar in only a few specimens, this species is intermediate between the slightly older Galerix symeonidisi and the slightly younger Parasorex pristinus. It may form part of the lineage leading from the genus Galerix to the younger genus Parasorex.