The following image shows two skulls - the one on the left is known as Pintubi-1. The one on the right is a modern Caucasian.
The skull features of the Australisoid race are very characteristic. With a squared jaw, very pronounced brow and unique dental features, this race is possibly the easiest to distinguish. This Specimen was found in New South Wales, Australia in the early 1900's and is believed to have been a member of the Bindaboo Tribe. - 
The Aboriginal skull in the pictures fits the typical description for "Australoids" since they have the largest browridges. If you're interested in what other races' skulls look like, here's the 3 basic groups. The Caucasoid/white skull is just the most commonly portrayed one, which is why other groups' skulls sometimes look "primitive" to people. - 
Given the apparent large morphological differences, is it true that this skull is representative of the Aboriginal people?