Salkhit skullcap from Mongolia shows archaic supraorbital morphology. Lacks chronometric date but possibly Middle to Late Pleistocene. Shares archaic traits with Zhoukoudian Locality 1 Homo erectus sample. Those traits persist in later northeast Asian hominins. Salkhit differs from Middle Pleistocene fossils with broader frontal bone. Salkhit has thinner supraorbital region than Middle Pleistocene samples. Modernization trend matches later hominins via encephalization and gracilization. Archaic features regionally predominant across Pleistocene northeast Asia. Not diagnostic of archaic species like Homo erectus. Supports archaic ancestry in later Asian hominins. Rules out strict replacement by modern Homo sapiens. Aligns with mosaic evolution regionally. Extends hominin presence north in Asia. Clusters with archaic Homo sapiens over pure moderns in prior analyses. Woolly rhinoceros nearby unreliable for 800 ka dating. Nihewan sites nearby indicate early northern Asian hominin activity.