Prior to the arrival of the modern Aborigines in Australia, an even more archaic group lived in the subcontinent.
The Kow Swamp skull from 22,000 YBP in Australia represents some of these people. This is one of the most archaic skulls ever found during the modern Homo sapiens era. Although Kow Swamp is called Homo Sapiens, the skull has prominent Homo Erectus features. It is probably a mix between more modern Sapiens types and more archaic and Erectus-like pre-Sapiens types. It is now known that pre-Sapiens archaic hominids survived in the form of Denisova Man from 39,000 YBP in southern Russia, Sulu Man from Indonesia 25,000 YBP, the Red Deer Cave people from central China, Flores Man from Flores Island in Indonesia, and Neandertals from the Russian subarctic, all from 12,000 YBP.
Based on probably true accounts of local people, Flores Man appears to have survived into the late 1800’s, when their habits of stealing human children and eating them finally enraged the local humans so much that they set fire to the main cave where the Flores People lived.
The Neandertals and Red Deer Cave people are assumed to have died out 12,000 YBP when their last traces were found.
Denisova Man is kn own only from the single cave in southern Russia 39,000 YBP, but his genes are also present in Papuans and Melanesians. These Australoid groups appeared in the region ~40,000 YBP. So Denisova Man was also present in Oceania around the same time that he was living in Russia.
Sulu Man is thought to be actually a very late surviving Erectus.
Flores Man is also Erectus, a very primitive type going all the way back to the earliest Habilis era of Erectus around the time of the split between Australopithecus.
Denisova Man is a new type resembling Neandertal and best seen as very early archaic Sapiens.
Red Deer Cave people are probably best seen as very late surviving Heidelbergensis types. Heidelbergensis is an archaic Sapiens type that is known from southern Europe, mostly Spain, from 500,000 YBP. They are best seen as Erectus-Sapiens transitionals.
Neandertals of course are archaic Sapiens similar to Denisovans.