Males have a dense tuft of hairs on the front of their long jaws.
The described male has a dark reddish-brown head and thorax; these are tan brown in the described female. Both have an abdomen mottled greyish brown and beige.
Austrarchaea aleenae is a tiny spider with a markedly elevated front body. It has two pairs of small horns on its head and three pairs of humps on the abdomen. Its male holotype was 3.10 millimetres long, with a carapace height of 2.63 millimetres.
When the spider was described as a new species in 2011, specimens collected more than 30 years earlier also contributed. The female chosen for the detailed description had been collected in February–March 1977. The paper also included males, females and juveniles collected in 1975. Some old labels retained the locality name Bulburin State Forest.
The male holotype, in contrast, was collected on 25 October 2010 by sifting elevated leaf litter. Alongside morphological comparisons, the study analysed DNA and reported genetic characters from three individuals that helped compare this species with others. Long-preserved specimens and recently collected material were brought together to document the species.
An extinction-risk assessment has not been added yet.
The authors considered the distribution potentially restricted in 2011, but reported that the species was abundant in Bulburin National Park and did not then regard it as a conservation concern. Maintaining forest and leaf-litter settings at documented sites and checking present-day occurrence would help update the evidence for conservation decisions.