Both males and females are small spiders.
The described male and female have an abdomen mottled greyish brown and beige, with three pairs of humps on its back.
In the described female Austrarchaea judyae, the rear head profile has two high points with a slight depression between them. In the male, the highest point lies near the rear margin. Males have a short brush of accessory hairs on the front of the basal cheliceral segment; the described female lacks this brush.
The 2011 study also genotyped six specimens. It identified three COI/COII nucleotide states that distinguished this species from the other south-eastern Queensland taxa examined. The authors did not describe these as unique across every mid-eastern Australian taxon in the study. Identification therefore combined morphology with genetic evidence whose comparison scope was explicitly regional.
An extinction-risk assessment has not been added yet.
In Conondale National Park, habitat of this spider, invasive plants are a management concern. The 2013 management statement amended in 2024 describes lantana suppressing native rainforest regeneration along Booloumba Creek. It calls for continued monitoring and control of invasive vines and early detection of new weed occurrences. These are regional rainforest-management commitments.