CRYPTOMASTRIDAE Derkarabetian & Hedin

Derkarabetian, Shahan, Starrett, James, Tsurusaki, Nobuo, Ubick, Darrell, Castillo, Stephanie & Hedin, Marshal, 2018, A stable phylogenomic classification of Travunioidea (Arachnida, Opiliones, Laniatores) based on sequence capture of ultraconserved elements, ZooKeys 760, pp. 1-36: 1

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CRYPTOMASTRIDAE Derkarabetian & Hedin

fam. n.

Family CRYPTOMASTRIDAE Derkarabetian & Hedin  fam. n.

Type genus.

Cryptomaster  Briggs, 1969

Type species.

Cryptomaster leviathan  Briggs, 1969


The Cryptomastridae  can be diagnosed from all other travunioids by the presence of a distal swelling on tibia II that bears enlarged setae (Figure 6A, C), a sexually dimorphic structure found only in males. Both genera are fairly distinctive. Cryptomaster  is easily identified as the largest (>2.5 mm body length) laniatorean in the Pacific Northwest of North America (Figure 6D) and largest member of Travunioidea  , although two size forms exist ( Starrett et al. 2016). Speleomaster  species are restricted to lava tubes showing extreme levels of troglomorphy with complete absence of eyes, extremely reduced pigmentation, and leg elongation (Figure 6B). Although unrelated, Speleomaster  and Speleonychia  are both highly troglomorphic lava tube dwellers in the Pacific Northwest, found in Idaho and Washington, respectively. Aside from their disjunct geographic distribution, Speleomaster  can be differentiated from Speleonychia  by the absence of a free ninth tergite and lateral sclerites, and by the presence of bifurcating tarsal claws of the hind legs ( Speleonychia  with a peltonychium). The cryptomastrid genera can be distinguished from the eastern North American Cladonychiidae  ( Erebomaster  + Theromaster  ) by the spination of the pedipalpal tarsus, previously noted by Briggs (1969, 1974). Cryptomastrids possess five prominent spines on the lateral margins of the pedipalpal tarsus, three on the prolateral margin and two on the retrolateral margin. Erebomaster  and Theromaster  possess three pairs of prominent lateral spines (in some Theromaster  , the two apical retrolateral spines are fused at the base). The Cryptomastridae  are unique in intestinal morphology, possessing a combination of an elongate and triangular DI (similar to Briggsus  and Isolachus  ), and shorter OD2 and OD3 (similar to the Paranonychidae  ) (Suppl. material 2: Figure 2).

Included genera and species.

Cryptomaster  . Described by Briggs (1969) and originally included only Cryptomaster leviathan  Briggs, 1969 from the Coastal Range of southwestern Oregon. A second species, Cryptomaster behemoth  Starrett & Derkarabetian, 2016, was described from the west-central Cascade Range of Oregon ( Starrett et al. 2016).

Speleomaster  . Briggs (1974) described the genus and both known species, Speleomaster lexi  Briggs, 1974 and Speleomaster pecki  Briggs, 1974, from lava tubes of the Snake River Plain in southern Idaho.