CLADONYCHIIDAE Hadzi , 1935

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

Family CLADONYCHIIDAE Hadzi, 1935

Type genus.

Erebomaster Briggs, 1969.

Type species.

Erebomaster flavescens Cope, 1872.

Diagnosis.

Some taxa have not been examined for the relevant characters, but tentative diagnostic characters may be found in the intestinal complex (Suppl. material 2: Figure 2). All Cladonychiidae that have been examined show a 2-3 branched, elongate, and triangular D1, and elongate OD3. In the Pacific Northwest of North America, cladonychiids are broadly sympatric with the Cryptomastridae and Paranonychidae . The above intestinal characteristics differentiate them from Cryptomastridae , which possess a relatively short and stout OD3, and the Paranonychidae , which possess a simple unbranched D1 (Suppl. material 2: Figure 2). The European taxa can be diagnosed from Travuniidae based on male genital morphology (Figure 7): travuniids have a widened and flattened glans with lateral wing-like extensions; the glans and shaft are undivided in Travunia and Dinaria . The penis musculature is restricted to the base in Holoscotolemon and Peltonychia , while the musculature of Trojanella is restricted to the apical portion of the shaft and glans.

Included genera and species.

Erebomaster (Figure 1B). Erebomaster is found in the eastern United States, and currently includes three species: E. flavescens Cope, 1872 with two subspecies E. f. flavescens from Wyandotte Cave in Indiana and E. f. coecus (Packard, 1888) from Carter Cave in Kentucky; E. weyerensis (Packard, 1888) from caves in West Virginia; and the relatively widespread E. acanthinus (Crosby & Bishop, 1924) with a distribution along and west of the Appalachian Mountains. A revision of Erebomaster taxa is needed.

Theromaster (Figure 1A). Consisting of two described species found in the eastern United States: T. brunneus (Banks, 1902) is relatively widespread in the southern Appalachian Mountains; T. archeri (Goodnight & Goodnight, 1942) from caves in Alabama.

Speleonychia (Figure 1I). A monotypic genus, Speleonychia sengeri Briggs, 1974 is a highly troglomorphic species restricted to lava tubes near Mt. Adams, in south-central Washington.

Briggsus (Figure 1G). The genus and all species were originally described by Briggs (1971b) as Pentanychus ; Özdikmen and Demir (2008) provided the replacement name. This genus consists of five described species all restricted to the moist coastal forests (>50 inches yearly rainfall) of Oregon and Washington in the Pacific Northwest: B. bilobatus (Briggs, 1971), B. clavatus (Briggs, 1971), B. flavescens (Briggs, 1971), B. hamatus (Briggs, 1971), and B. pacificus (Briggs, 1971).

Isolachus (Figure 1H). A monotypic genus, Isolachus spinosus Briggs, 1971 is restricted to northwest Oregon and southwest Washington.

Holoscotolemon (Figure 1D). A European genus with eight species. Six species are restricted to the Alps, primarily from Italy and Austria: H. unicolor Roewer, 1915; H. lessiniensis Martens, 1978; H. oreophilus Martens, 1978; H. franzinii Tedeschi & Sciaky, 1994; H. monzinii Tedeschi & Sciaky, 1994; and H. naturae Tedeschi & Sciaky, 1994. H. querilhaci (Lucas, 1864) is found in the Pyrenees of southern France and H. jaqueti (Corti, 1905) is recorded from eastern Europe in Romania, Ukraine, and former Yugoslavia.

Peltonychia (Figure 1E). A genus with a long history, Peltonychia includes the first described travunioid species, P. leprieurii . This genus of eight species is almost entirely known only from caves in central Europe throughout the Pyrenees and Alps (Suppl. material 2: Figure 3). Peltonychia leprieurii is found in the Alps of northern Italy. Peltonychia clavigera , P. navarica (Simon, 1879), P. piochardi (Simon, 1872), and P. sarea (Roewer, 1935) are all found in the Pyrenees of northern Spain and southern France. P. gabria Roewer, 1935 is recorded from Trieste, Italy; P. postumicola (Roewer, 1935) is recorded from eastern Italy and western Slovenia; and P. tenuis Roewer, 1935 is recorded from northern Slovenia. Records from Trieste, Italy and Slovenia are conclusively shown to be in error, and P. postumicola and P. tenuis are morphologically similar to P. clavigera ( Novak and Gruber 2000). As such, it is unclear how many actual species are included.

Arbasus . A monotypic genus, the highly troglomorphic Arbasus caecus (Simon, 1911) is only known from Grotte de Pène Blanque in the Pyrenees of southern France.

Buemarinoa . A monotypic genus, the highly troglomorphic Buemarinoa patrizii Roewer, 1956 is only known from the Grotte del Bue Marino in Sardinia, Italy.

Proholoscotolemon Ubick & Dunlop, 2005. A monotypic genus, P. nemastomoides (Koch & Berendt, 1854) is known from specimens preserved in Baltic amber. The specimens were redescribed by Ubick and Dunlop (2005) and based on morphological similarity and geography it is interpreted as the ancestor of, or sister group to, Holoscotolemon .

Remarks.

Peltonychia is polyphyletic, in some cases with strong support (Figure 5). The sampled species are from two separate geographic regions: P. clavigera from the Pyrenees of northern Spain and southern France, and P. leprieurii from the Alps of northern Italy. Accounting for the locality errors in Italy and Slovenia mentioned above, Peltonychia is geographically split into two regions: P. leprieurii in northern Italy, and the remaining species in the Pyrenees. The male genitalia of four species of Peltonychia have been examined: P. leprieurii , P. clavigera , P. gabria , and P. postumicola . Based on these genitalic drawings ( Chemini 1985, Martens 1978, Thaler 1996), it is obvious that P. leprieurii is very divergent from the other three Peltonychia , which are very similar (Suppl. material 2: Figure 3). This concordance between geography, genital morphology, and our phylogenomic analyses support the separation of Peltonychia into two genera. However, we refrain from formally making this taxonomic change until all relevant species can be studied.

The sister relationship of Speleonychia to the traditional Briggsinae ( Briggsus + Isolachus ) is not surprising given the close geographic proximity of these genera and shared presence of a free ninth tergite and lateral sclerites. The distinct generic status of Arbasus and Buemarinoa has been doubted ( Kury and Mendes 2007). The morphological distinction between Arbasus and Buemarinoa is minimal and entirely based on tarsal segmentation ( Kury and Mendes 2007), which is typical of the "Roewerian classification" system that resulted in taxa being over split based on irrelevant characters (e.g., Kury et al. 2014, Kury and Pérez-González 2015). Aside from the original descriptions with basic drawings ( Roewer 1935, 1956), virtually no taxonomic work has been conducted on Arbasus and Buemarinoa . However, Kury and Mendes (2007) note that they "both look superficially like Hadziani [= Peltonychia ], but with clear troglomorphic traits …”, and their inclusion in Cladonychiidae here seems justified.