Female: based on the presence of single dorsal shield (Fig. 1), ovipore covered by paired latigynal shields and unpaired mesogynal shield (Fig. 2) and the absence of ambulacra (including claws and pulvillus) on tarsi I (Fig. 2), it belongs to the infraorder Antennophorina, suborder Trigynaspida.
Female: Additional character states separate this genus from other genera in Antennophorina: 4-5 pairs of setae on latigynal shields (Fig. 2), mesogynal shield truncated anteriorly (Fig. 2), dorsal shield and ventral opisthosoma hypertrichous (Figs. 1,2), anal shield on large ventral plate (Fig. 2).
Female: Placement of this genus in a family is unsettled. Celaenosthanus was originally placed in the family Antennophoridae (Vitzthum, 1930). Later, in a revision of Trigynaspida, it has been suggested that Celaenosthanus represents either a separate subfamily in the family Diplogyniidae, a family in the superfamily Celaenopsoidea, or a family outside Celaenopsoidea (Kethley, 1977). The following diagnostic characters separating Celaenosthanus from other Celaenopsoidea were cited: the vaginal sclerites, although rather large, are membranous, the leg chaetotaxy is much richer than any known celaenopsoid species, the chelicerae are somewhat reduced, the metapodal sclerotization is completely separate from the ventrianal sclerotization, legs I are antenniform, and the peritreme is laterally hypertrophied. Many of these diagnostic character states were scored by Kethley from actual specimens (not available to us).