The male has an almost spherical abdomen in side view.
The abdomen has very low vestiges of humps rather than projecting dorsal tubercles.
Male Zephyrarchaea marki has a reddish-brown dorsal abdominal plate. Joined at the front to ventral sclerites, it extends over nearly the anterior two-thirds of the abdomen. The name-bearing male measures 2.77 millimetres in total length, while the femur of its first leg alone is 2 millimetres long.
Juvenile specimens also preserve clues to this tiny spider’s identity. Three juveniles were collected at Thistle Cove, Western Australia, in July 2009; two adult males and another juvenile followed in June 2010. The 2012 description uses DNA data corresponding to three of those juveniles and reports nine diagnostic nucleotide differences in two mitochondrial genes, distinguishing marki from the other sampled taxa. Alongside adult morphology, genetic information from young specimens contributed to characterising this species.
An extinction-risk assessment has not been added yet.
In the 2012 description, marki was known from Thistle Cove in Cape Le Grand National Park. The authors identified fire, dieback disease affecting Banksia vegetation, and climate change as potential threats to that population. Dense coastal thicket and its accumulated leaf litter were reported as the spider’s specific setting.
The Western Australian South Coast regional conservation plan of December 2025 proposes biennial post-fire habitat surveys for this species and four other assassin spiders to assess whether they return after fire.