Nahual, Monjaraz-Ruedas & Prendini & Francke, 2019

Monjaraz-Ruedas, Rodrigo, Prendini, Lorenzo & Francke, Oscar F., 2019, Systematics Of The Short-Tailed Whipscorpion Genus Stenochrus Chamberlin, 1922 (Schizomida: Hubbardiidae), With Descriptions Of Six New Genera And Five New Species, Bulletin of the American Museum of Natural History 2019 (435), pp. 1-93 : 52-54

Nahual , gen. nov.

Figures 3 , 6, 7F, 9A, B, 10B, 11A, 12B, 13F, 14C, 19G–I, 20A, 21G–L, 22A, B; tables 1, 3, 8

Stenochrus (part): Reddell and Cokendolpher, 1991: 1, 3.

Schizomus mexicanus group (part): Rowland 1975b: 37, 39, 164, 165, 167, 168, 173, 185, 209, 214, 216, 218, 220, 222, 224, 228, 255, 280, 301, 303, 320, 321, 348–350, 365, 366, 368, 369, 376, 387, 390–393, 395; Rowland and Reddell, 1979a: 165, 171; 1979b: 90, 107; 1980: 1–10, 11, 15–20; Reddell, 1981: 126; Rowland and Reddell, 1981: 19, 20, 41; Reddell and Cokendolpher, 1986: 32, 34; Camilo and Cokendolpher, 1988: 53, 57; Armas, 1989a: 7; Armas and Abud-Antun, 1990: 14, 18; Reddell and Cokendolpher, 1991: 1, 3; 1995: 82, 99, 101–104; Krüger and Dunlop, 2010: 52; Monjaraz-Ruedas and Francke, 2015: 452; 2016: 781–783, 804; 2018: 189, 212.

TYPE SPECIES: Schizomus pallidus Rowland, 1975 [= Nahual pallidus (Rowland, 1975) , comb. nov.], type species, here designated.

DIAGNOSIS: Nahual , gen. nov., may be separated from other hubbardiid genera by the following combination of characters. Cheliceral movable finger with lamella or single tooth (in Nahual caballero ( Monjaraz-Ruedas and Francke, 2018) , comb. nov.) (fig. 12B, C); single guard tooth at end of serrula; setal group G3 with G3-3 setae situated anteriorly (except in N. bokmai , sp. nov.) (fig. 13F). Propeltidium anterior process with two anterior setae (one posterior to the other) and three pairs of dorsosubmedian setae (fig. 11A); corneate eyes absent. Metapeltidium entire. Tegument without clavate setae. Pedipalps homeomorphic; trochanter with mesal spur and projected, fan-shaped apical process (fig. 7F); femur Fv 1 and Fv 2 setae spiniform, Fvr 1–3 setae present (seta Fvr 4 present in N. lanceolatus , comb. nov., polymorphic in N. bokmai and N. pallidus , comb. nov.); patella with four or five acuminate Pe setae and five feathered Pm setae; tibial setal formula 5(6)-5-6 (Ter-Tmr-Tir) (fig. 14C). Leg IV femur anterodorsal margin produced at ca. 90° angle. Opisthosomal tergite II with one pair of setae (Dm). Opisthosomal segments IX–XII not elongated; XII (♂) without posterodorsal process. Pygidial flagellum (♂) dorsoventrally compressed, elliptical (lanceolate in N. lanceolatus ), with pair of dorsosubmedian circular depressions separated from each other (pits), or circular slumps (in N. caballero ) (figs. 19G–I, 20A); flagellum (♀) with two annuli (fig. 21G–L). Spermathecae (♀) with two pairs of lobes, of similar width and length; median lobes with apex directed vertically, sclerotized along entire length, sclerotizations increasing in size, creating appearance of leafy tree (fig. 9A, B); lateral lobes with apex directed laterally, unsclerotized; lobes without bulbs; median lobe bases posterior to lateral lobe bases (fig. 10C, D), without duct openings; chitinized arch arrow shaped, with anterior branch linear, lateral tips lobed, wide, and projected; gonopod extremely wide and long, together with chitinized arch, creating appearance of an arrow.

COMPARISONS: Species of Nahual , gen. nov., resemble species of Stenochrus in the presence of a pair of dorsosubmedian pits in the male pygidial flagellum. However, the flagellum of Nahual possesses only one pair of pits, which are well separated from each other (fig. 20A), whereas the flagellum of Stenochrus possesses an additional dorsal depression associated with the pits, which

Vm3Vm 55 4 Dl 3 Dl 3 Vl 2are situated closely adjacent to each other (fig. 20B). Additionally, the Dl 3 setae are situated posterior to the Vl 2 setae on the male pygidial flagellum in Nahual , whereas these setae are aligned in Stenochrus . Lastly, species of Nahual possess a lamella on the cheliceral movable finger, which is smooth in Stenochrus .

Species of Nahual also differ from species of Baalrog , gen. nov., and Stenochrus in the presence of spiniform setae Fv 1 and Fv 2 on the pedipalp femur, which are absent in the other genera. The median and lateral lobes of the female spermathecae are linear and similar in length in Nahual , whereas the median lobes are curved, and the lateral lobes reduced in length, in Baalrog and Stenochrus .

The female spermathecae of Nahual resemble those of Heteroschizomus , stat. rev., in possessing median and lateral lobes that are linear and similar in length. However, the lobes are sclerotized in Nahual and unsclerotized in Heteroschizomus .

ETYMOLOGY: The generic name is a Nahuatl word used in several Mesoamerican cultures for wizards with the ability to transform themselves into animals. It is masculine in gender.

INCLUDED SPECIES: Nahual bokmai , sp. nov.; Nahual caballero ( Monjaraz-Ruedas and Francke, 2018) , comb. nov.; Nahual lanceolatus (Rowland, 1975) , comb. nov.; Nahual pallidus (Rowland, 1975) , comb. nov.

DISTRIBUTION: Nahual , gen. nov., is endemic to the Mexican states of Oaxaca and Veracruz (fig. 3). Species of Nahual are codistributed with species of Baalrog , gen. nov., in the Sierra de Zongolica of Veracruz, and extend southward to the Sierra Madre Oriental, in northern Oaxaca. However, species of Nahual are epigean, inhabiting tropical rainforests, and some species occur at elevations above 1800 m, whereas Baalrog are troglobitic, occurring mostly at elevations below 1600 m.

NATURAL HISTORY: Although the type localities of N. lanceolatus , comb. nov., and N. pallidus , comb. nov., are caves, the species of Nahual , gen. nov., are primarily epigean, occurring under rocks and inside rotten logs in tropical forests. Both N. lanceolatus and N. pallidus have been collected on the surface, suggesting they are facultatively cavernicolous. Baalrog , gen. nov., a strictly cavernicolous genus, is codistributed in the same area as Nahual .

REMARKS: Rowland and Reddell (1980) assigned Schizomus lanceolatus Rowland, 1975 , to the goodnightorum group, due to the lanceolate shape of the male pygidial flagellum (the female of this species was unknown), and Schizomus pallidus Rowland, 1975 , to the mexicanus group, due to the shape of the male pygidial flagellum and the female spermathecae. The discovery of the female of N. lanceolatus , comb. nov., demonstrated a close relationship with N. pallidus , comb. nov., and supported their inclusion, together with the new species, in Nahual , gen. nov., based on their similar female spermathecae and male pygidial flagella (e.g., with a pair of dorsal pits), as well as DNA sequence data (fig. 6). The enlarged pygidial flagellum of the male of N. lanceolatus appears to be autapomorphic and differs from the enlarged flagella observed in species of Heteroschizomus , stat. rev., by the absence of a posterior constriction.

Figures

FIG. 3. Map of central Mexico, plotting known locality records for the short-tailed whipscorpion genera Harveyus, gen. nov. (squares), and Nahual, gen. nov. (circles) (Schizomida: Hubbardiidae Cook, 1899), based on data from museum collections and the literature.