 The age of the subfamily seems to be relatively old, originating during the Early Oligocene Glacial Maximum, estimated 48.6-35.4 million years ago They early diversified into genera about 32.5 million years ago.The extant genera show narrow distributions in distant geographic regions, which may have resulted from speciation by isolation and following extinction events.The areals of "Aphanisma" in California and "Oreobliton" in North-Africa are interpreted als remnants from a Beringian ancestor, the disjunction circa 15.4-9.2 million years ago.