van Rietschoten who sent it to paleontologist Eugène Dubois who subsequently found the second skull in September 1890.

Dubbed Wajak Man, and formerly classified by Dubois as a separate species (Homo wadjakensis) and Pramujiono as a subspecies of Homo erectus in a self-published paper,[1] the skulls are now recognized as an early anatomically modern human fossil.

[2][3] Their morphological characteristics have been described as showing affinity to both proto-Australoid (intermediate between Solo Man and contemporary Australo-Melanesians) and to Mongoloid populations, specifically Chinese people, sharing specific Mongoloid traits such as flat face.

Anthropologists such as Bulbeck and Turner concluded, based on these and other findings, that "southern Mongoloids" are indigenous to Southeast Asia, with the proto-Mongoloid population to have originated in the Sunda region or Mainland Southeast Asia, while their distant relatives, the Australo-Melanesians originated in the Sahul region with at least 50,000 years of divergence.

[4] Anthropologist Paul Storm argues that "the most likely interpretation is to consider the Wajak skulls as Mesolithic robust representatives of the present inhabitants of Java", Javanese people.