The male has two pairs of humps on the back of the abdomen.
The head and thorax are dark reddish brown, and the legs have darker rings.
The male used to describe Austrarchaea wallacei measured 3.28 mm long, with the femur of its first leg alone measuring 3.01 mm. Its carapace was 1.17 mm long and 2.49 mm high, giving it a tall profile alongside elongated legs.
When described as a new species in 2012, the available material was one male. Its collecting label records a sampling period from 6 December 1990 to 17 January 1991 at Mount Misery, Queensland. This specimen, collected by the Queensland Museum and collaborators, became the name-bearing type of a newly recognised species.
The name wallacei honours Doug Wallace’s enthusiasm for arachnology and support for the people studying spiders. The original paper highlights his contributions to Australian, particularly Queensland, arachnology and his work founding and fostering the Rockhampton Arachnological Society. The name connects a small preserved animal with the people who helped build knowledge of spiders.
An extinction-risk assessment has not been added yet.
The 2012 description was based on one male, and the authors lacked information to assess its conservation status. In a May 2020 statement, the Queensland government explained that the whole Monkhouse Timber Reserve, which contains the collecting locality, was included in the Wet Tropics World Heritage Area. Surveys at the original locality and in surrounding rainforest would add information on occurrence and habitat needed for species-specific conservation decisions.