Typhlochactas mitchelli Sissom, 1988

Vignoli, Valerio & Prendini, Lorenzo, 2009, Systematic Revision Of The Troglomorphic North American Scorpion Family Typhlochactidae (Scorpiones: Chactoidea), Bulletin of the American Museum of Natural History 2009 (326), pp. 1-94 : 59-75

Typhlochactas mitchelli Sissom, 1988

( Figs. 1B , 4 , 5E , 8B , 9I, 9J , 12D , 26–28 )

Typhlochactas mitchelli Sissom, 1988: 365–371 , figs. 1–14, table 1.

Typhlochactas mitchelli : Kovařík, 1998: 142; Sissom and Cokendolpher, 1998: 285, 287 (table 1); Beutelspacher Baigts, 2000: 20, 52, 54, 151, map 22; Sissom, 2000b: 499; Volschenk et al., 2001: 161; Soleglad and Sissom, 2001: 40, fig. 39; Soleglad and Fet, 2001: 31; 2003a: fig. 11; 2003b: 28, 30, 32, 76; Volschenk and Prendini, 2008: 236 (table 1), 249, 250; Botero-Trujillo and Francke, 2009: 2.

Typhlochactas mitcheli : Beutelspacher Baigts, 2000: 143.

TYPE MATERIAL: Mexico: Oaxaca: Município de San José Tenango: Holotype: 1 ³ ( AMNH), Cerro Ocote [18 ° 08957.50 N 96 ° 43959.10W], 5 mi. S San José de Tenango, A. Grubbs, A. Cressler and P. Smith, IV.1987. Paratypes: 1 ³, 1 subad. ♀ ( AMNH), same data.

DIAGNOSIS: Typhlochactas mitchelli is most closely related to T. sylvestris (fg. 4). It may be separated from T. sylvestris and all other Typhlochactas species by the following combination of characters. Cheliceral fixed finger with three teeth (subdistal absent); median and basal teeth not fused into bicusp. Cheliceral movable finger with three dorsal teeth (subdistal teeth absent). Carapace, anterior margin with well-developed median projection (epistome). Pedipalp chela fixed and movable fingers, median denticle row comprising four or five and five or six oblique primary subrows, respectively; basal primary subrow of movable finger similar in length to other subrows; terminal denticle of fixed finger slightly larger than preceding denticles, fingertips interlocking evenly when closed. Legs with prolateral pedal spurs. Telotarsi with ventromedian row of spinules. Sclerites of genital operculum (♀) fused, but loosely connected by membrane along entire length of suture.

DESCRIPTION: The following description supplements the original description by Sissom (1988).

Color: Holotype and paratype ³, pedipalp femur, patella, and mesosoma, Yellow Ocher (123C); pedipalp chela and telson, Robin Rufous (340); metasoma, Brick Red (132A). Subadult ♀ paratype, uniformly Buff (124).

Chelicerae: Manus, dorsal and ventral surfaces smooth; dorsal surface with three microsetae near base of fixed finger; movable finger with single microseta. Fixed finger, dorsal margin with three teeth (distal, median and basal; fig. 5E); median and basal teeth equal, not fused into bicusp, considerably smaller than distal tooth. Movable finger, internal distal and external distal teeth not opposable, internal distal tooth at most partially overlapping external distal tooth in dorsal view; dorsal margin with three teeth (internal distal, median, and basal), internal distal tooth largest, median smallest; ventral surface with serrula extending two-thirds of finger, covered in part by dense brush of macrosetae.

Carapace: Length greater than anterior width (table 9). Anterior margin sublinear, with small median projection (epistome); asetose (fig. 26A). Posterior margin weakly concave medially; asetose. Median and lateral ocelli absent. Median longitudinal, posterolateral, and posterior transverse sulci shallow. Surface smooth to finely granular, acarinate, with scattered microsetae.

Pedipalps: Femur, ventroexternal carina obsolete, granular, dorsoexternal carina vestigial, restricted to proximal third; other carinae absent; intercarinal surfaces moderately granular (fig. 28A). Patella acarinate; intercarinal surfaces moderately granular (fig. 28B–D). Chela stout, with broad, round- ed manus (fig. 27); fingers short, slightly longer than manus (table 9). Manus acarinate; dorsointernal and, to a lesser extent, dorsoexternal surfaces, markedly granular distally; fixed and movable fingers, proximal surfaces, markedly granular, without denticle rows. Fixed finger, median denticle row comprising four or five oblique primary subrows, restricted to distal two-thirds of finger (fig. 9I); internal denticles larger than external denticles; terminal denticle small, slightly larger than preceding denticles, fingertips interlocking evenly when closed. Movable finger, median denticle row comprising five or six oblique primary subrows, restricted to distal two-thirds of finger ( Fig. 9J ); basal primary subrow short, similar in length to distal subrow; terminal denticle small.

Trichobothria: Femur with three trichobothria (fig. 28A): one external (e), one dorsal (d), one internal (i). Patella with 19 trichobothria (fig. 28B–D), five petite (d 1, d 2, et 2, esb 2, eb 2), one accessory (em 3): two ventral (v 1, v 2); 14 external (et 1 – et 3, est, em 1 – em 3, esb 1, esb 2, eb 1 – eb 5); two dorsal (d 1, d 2); one internal (i). Chela with 26 trichobothria (fig. 27), seven petite (V 1, Et 4, Et 5, Esb, Db, esb , db): 16 on manus, four ventral (V 1 –V 4), 10 external (Et 1 – Et 5, Est, Esb, Eb 1 – Eb 3), two dorsal (Db, Dt); 10 on fixed finger, four external (et, est, esb , eb), four dorsal (dt, dst, dsb, db), two internal (it, ib).

Legs: All segments setose; basitarsi, ventral surface with three or four pairs of macrosetae. Basitarsi I–IV with prolateral pedal spurs; I and II, proventral surface with short subdistal row of closely aligned spinules. Telotarsi, dorsomedian lobe with one microseta; ventral surface with curved row of spinules, proximally, and straight ventromedian row of spinules, flanked by three or four submedian pairs of subspiniform macrosetae; ungues moderately developed, equal in length; dactyl short, robust.

Tergites: Surfaces acarinate; I–V, smooth, VI and VII sparsely, coarsely granular (fig. 26A). Surfaces and margins with sparse microsetae.

Sternum: Posterior width greater than length (fig. 8B); apex slightly rounded; lateral margins subparallel; lateral lobes flat; posterior depression very shallow. Surface with approximately 10 microsetae.

Genital operculum: Sclerites (³) suboval, completely divided; genital papillae large, protruding distinctly beyond posterior edges (fig. 8B). Sclerites (♀) fused, but loosely connected by membrane along entire length of suture. Surfaces with few microsetae.

Pectines: Pectinal plate, surface with several microsetae. Lamella comprising five segments (fig. 8B); surfaces covered with microsetae. Tooth count, 5/5; teeth similar in shape and size, except for distal tooth, slightly enlarged, lobate.

Sternites: Surfaces acarinate, smooth, sparsely setose (fig. 26B). Respiratory spiracles (stigmata) small, round, situated posterolaterally.

Metasoma: Metasoma stout, segments I– III width greater than length, IV and V length greater than width (fig. 12D), progressively increasing in length, decreasing in width (table 9); segment V longer than carapace. Dorsosubmedian carinae, segments I–IV, obsolete, distal granules not noticeably

TABLE 9

Meristic data for Typhlochactas mitchelli Sissom, 1988 , and Typhlochactas sylvestris Mitchell and Peck, 1977 Measurements (mm) follow Francke et al. (2009). Abbreviations as follows: AMNH 5 American Museum of Natural History, New York

TABLE 9 (Continued)

larger than preceding granules (fig. 12D). Dorsolateral carinae, segment V, obsolete. Dorsolateral, median lateral and ventrosubmedian carinae, segments I–IV, ventrolateral carinae, segments I–V, and ventromedian carina, segment V, absent. Dorsal intercarinal surfaces, segments I–V, slightly concave. Segments I–IV, dorsolateral surfaces coarsely granular, other intercarinal surfaces smooth; segment V entirely granular except posteroventrally. Surfaces of all segments with short microsetae; V additionally with several longer macrosetae.

Telson : Vesicle globose, wider than segments II–V (table 9), flattened to slightly concave dorsally, rounded ventrally; anterodorsal lateral lobes absent (fig. 12D); lateral and ventral surfaces granular, with several long and short setae posteriorly. Aculeus short, moderately curved, arising abruptly from vesicle.

Hemispermatophore: Unknown (neither adult male specimens dissected).

Ontogenetic variation: Paler, cream coloration and less elongated, more rounded telson of subadult female attributed to ontogenetic rather than sexual variation. Subadult female retains vestigial subrows of denticles extending to near base of chela fixed and movable fingers (i.e., five subrows on fixed finger, six on movable finger) and there are no internal denticles on fourth row of fixed finger or fifth row of movable finger. These observations suggest a reduction in number of subrows in the adult occurs at the final instar ( Sissom, 1988) or else that it is a sexually dimorphic character.

Sexual dimorphism: Males exhibit more pronounced granulation, completely divided genital operculum and genital papillae.

Geographical variation: All specimens from same locality.

REMARKS: Typhlochactas mitchelli and T. sylvestris are the smallest species of the family and among the smallest known scorpions. Adults measure less than 10 mm in total length (table 9).

DISTRIBUTION: Known only from the type locality, Cerro Ocote, near San José de Tenango, Oaxaca, Mexico (fig. 1B). This locality is part of the same mountain range (Sistema Montañoso Poblano Oaxaqueño) in which T. sylvestris was collected.

ECOLOGY: This endogean (humicolous) species was hand-collected from the surfaces of small stones 1 to 2 feet below the surface, in crevices and alongside rock faces excavat- ed from beneath leaf litter, wood debris, roots, small stones and slight amounts of soil, in a montane forest (A.G. Grubbs, personal commun.). This habitat is very similar to that of Belisarius xambeui , an endogean scorpion from the Pyrenees of France and Spain, often found under stones deeply embedded in forest litter ( Auber, 1959).

Typhlochactas reddelli Mitchell, 1968 ( Figs. 1B , 2A, 2B , 4 , 5F , 9K, 9L , 12E , 29–31 ; table 8)

Typhlochactas reddelli Mitchell, 1968: 753 , 762– 772, 774–776, figs. 22–41, table 1.

Typhlochactas reddelli : Reddell, 1971a: 26; 1971b: 217; Mitchell, 1971: 135, 138, 143, 145, 146, figs. 21–23, 25, 27; Reddell, 1973: 32, 37; Vachon, 1974: figs. 167, 199–210; Soleglad, 1976: 254; Mitchell and Peck, 1977: 159, 162, 164, 167, 168; Reddell, 1981: 45, 115, fig. 17; Francke, 1982a: 59, 60, figs. 26, 30, 35; Lourenço and Francke, 1985: 3, 5 (table 1); Francke, 1986: 5, 7, 8, figs. 20– 22; Sissom, 1988: 365; Armas, 1994: 18, 21; Lourenço, 1994: 182, 183; Sissom and Cokendolpher, 1998: 285–287 (table 1); Sissom, 2000b: 499; Soleglad and Fet, 2003b: 30, 76; Lourenço et al., 2004: 1152, 1153; Prendini and Wheeler, 2005: figs. 18–23; Lourenço and Goodman, 2008: 667; Volschenk and Prendini, 2008: 236 (table 1), 249.

Typhlochactas reddeli : González-Sponga, 1974: 56.

Typlochactas redelli : Díaz Najera, 1975: 4, 33.

Typhlochactas redelli : Lourenço, 1981: 660; Kovařík, 1998: 142; Beutelspacher Baigts, 2000: 18, 20, 52, 54, 147, 151, map 22.

TYPE MATERIAL: Mexico: Veracruz: Município de Tlilapan: Holotype: 1 ♀ ( AMNH), La Cueva del Ojo de Agua de Tlilapan, Tlilapan , ca. 5 km S Orizaba [18 ° 489230 N 97 ° 059590W], 1400 m, J. Reddell, J. Fish and T. R. Evans, 4.VIII.1967.

DIAGNOSIS: Typhlochactas reddelli is most closely related to the monophyletic group comprising T. mitchelli and T. sylvestris (fig. 4). It may be separated from these and other Typhlochactas species by means of the following combination of characters. Cheliceral fixed finger with four teeth (subdistal present); median and basal teeth fused into a bicusp. Cheliceral movable finger with five dorsal teeth (two subdistals present). Carapace, anterior margin with well-developed median projection (epistome). Pedipalp chela fixed and movable fingers, median denticle row comprising six and seven primary subrows, respectively; basal primary subrow of movable finger similar in length to other subrows; terminal denticle of fixed finger considerably larger than preceding denticles, hooklike, fingertips interlocking unevenly when closed. Legs with prolateral pedal spurs. Telotarsi without ventromedian row of spinules. Sclerites of genital operculum (♀) fused, but loosely connected by membrane along entire length of suture.

DESCRIPTION: The following description of the holotype (fig. 29) supplements the original description by Mitchell (1968) and additional data provided by Mitchell (1971) and Francke (1982 a, 1986).

Color: Carapace, pedipalp femur and patella, legs, tergites, sternites, metasoma, and telson, Yellow Ocher (123C); pedipalp chela, Pratt’s Rufous (140). Aculeus and denticle rows of pedipalp fingers darker.

Chelicerae: Manus, dorsal and ventral surfaces smooth; dorsal surface with two microsetae situated near base of fixed finger; movable finger, dorsal surface with two microsetae. Fixed finger, dorsal margin with four teeth (distal, subdistal, median, and basal; fig. 5F); distal tooth largest, median and basal teeth equal, fused into bicusp. Movable finger, internal distal and external distal teeth opposable, internal distal tooth completely overlapping external distal tooth in dorsal view; dorsal margin with five closely aligned teeth (internal distal, two subdistal, median, and basal) situated on slightly convex ridge, internal distal tooth largest, median tooth slightly larger than subdistal and basal teeth (all similar in dimensions); ventral surface with serrula covering almost entire length of finger, comprising long tines, all equal in length, partially covered by dense brush of macrosetae.

Carapace: Length greater than anterior width (table 8). Anterior margin weakly concave, with small median projection (epistome) and few microsetae (fig. 29A). Posterior margin weakly convex; asetose. Median and lateral ocelli absent. Median longitudinal, posterolateral and posterior transverse sulci shallow. Surface acarinate, smooth, with few microsetae.

Pedipalps: Femur, ventroexternal carina obsolete, granular; other carinae absent (fig. 31A). Intercarinal surfaces mostly smooth, with few small granules proximally, and covered with microsetae. Patella longer than femur (table 8); acarinate, with three granules on ventrointernal margin (fig. 31B– D). Intercarinal surfaces covered with microsetae. Chela stout, fingers relatively short, slightly longer than manus (table 8). Manus acarinate (fig. 30); surfaces mostly smooth; dorsal and ventral surfaces with few granules distally; internal surface with pair of prominent, isolated granules situated close togeth- er at base of fixed finger; fingers, internal and external surfaces setose. Fixed finger, median denticle row comprising six oblique primary subrows, terminal subrow shorter, third subrow longer than other subrows (fig. 9K); internal denticles larger than external denticles; terminal denticle considerably larger than preceding denticles, hooklike, fingertips interlocking unevenly when closed. Movable finger, median denticle row comprising seven oblique primary subrows, terminal subrow shorter, basal subrow slightly longer than other subrows (fig. 9L); terminal denticle smaller than on fixed finger.

Trichobothria: Femur with three trichobothria (fig. 31A): one external (e), one dorsal (d), one internal (i). Patella with 19 trichobothria (fig. 31B–D), five petite (d 1, d 2, et 2, esb 2, eb 2), one accessory (em 3): two ventral (v 1, v 2); 14 external (et 1 – et 3, est, em 1 – em 3, esb 1, esb 2, eb 1 – eb 5); two dorsal (d 1, d 2); one internal (i). Chela with 26 trichobothria (fig. 30), seven petite (V 1, Et 4, Et 5, Esb, Db, esb , db): 16 on manus, four ventral (V 1 – V 4), 10 external (Et 1 – Et 5, Est, Esb, Eb 1 – Eb 3), two dorsal (Db, Dt); 10 on fixed finger, four external (et, est, esb , eb), four dorsal (dt, dst, dsb, db), two internal (it, ib).

Legs: All segments smooth, setose, especially femora and telotarsi. Basitarsi I and II, proventral surface with short subdistal row of closely aligned spinules; I–IV with prolateral pedal spurs. Telotarsi, dorsomedian lobe with one microseta; ventral surface without spinules, and with four or five ventrosubmedian pairs of subspiniform macrosetae; ungues long, well developed, curved, equal in length; dactyl short, slightly curved.

Tergites: Surfaces I–VI, smooth, acarinate; VII, mostly smooth, granular posterolaterally, dorsosubmedian carinae vestigial, reduced to few posterior granules, dorsolateral carinae absent (fig. 29A). Lateral and posterior margins with microsetae.

Sternum: Posterior width greater than length; apex rounded; lateral margins subparallel; lateral lobes flat; posterior depression shallow. Surface sparsely covered with microsetae.

Genital operculum: Sclerites (³) completely divided; genital papillae protruding distinctly beyond posterior edges of opercula. Sclerites (♀) fused, but loosely connected by membrane along entire length of suture.

Pectines: Pectinal plate, surface with two macrosetae situated mediolaterally. Lamella comprising three segments, demarcated by faint sutures; surfaces covered with microsetae. Tooth count, 5/5; teeth oval; proximal and distal teeth slightly larger.

Sternites: Surfaces acarinate, smooth (fig. 29B). Surfaces and margins with few, scattered setae. Respiratory spiracles (stigmata) small, round, situated posterolaterally.

Metasoma: Segments elongated, progressively increasing in length, decreasing in width (table 8), I and II width greater than length, III width equal to length, IV and V length greater than width. Dorsosubmedian carinae, segments I–IV, obsolete, composed of few stout granules, distal granules not noticeably larger than preceding granules. Dorsolateral carinae, segment V, obsolete, complete. Ventrolateral carinae, segment V, obsolete, complete, comprising spiniform granules increasing in size posteriorly. Dorsolateral, median lateral, ventrolateral, and ventrosubmedian carinae, segments I–IV, and ventromedian carina, segment V, absent. Dorsal intercarinal surfaces, segments I–V, slightly concave, smooth. All segments setose, especially on ventral and lateral surfaces. Anal arch with macro- and microsetae and few granules ventrolaterally.

Telson : Vesicle globose, shorter than metasomal segment V (table 8), flattened dorsally, rounded ventrally; anterodorsal lateral lobes absent; surfaces mostly smooth, with scattered granules near base of aculeus; ventral surface with scattered long and short macrosetae, increasing in number posteriorly. Aculeus short, weakly curved, arising gradually from vesicle (fig. 12E).

Hemispermatophore: Adult male unknown.

Ontogenetic variation: Juveniles paler in coloration.

Sexual dimorphism: Adult male unknown. Juvenile male exhibits completely divided genital operculum and genital papillae.

Geographical variation: All specimens from same locality.

REMARKS: The holotype is severely damaged (fig. 29): the mesosoma is broken, the metasoma broken in two places, and dextral leg II is disarticulated.

DISTRIBUTION: Known only from the type locality, La Cueva del Ojo de Agua de Tlilapan, in the karstic region of Orizaba, Veracruz (eastern Mexico) (figs. 1B, 2A, 2B).

ECOLOGY: The cave in which this troglobitic species was collected, comprises two large horizontal rooms and a wide entrance ( Mitchell, 1968; Reddell, 1981). According to the original description ( Mitchell, 1968), the holotype was collected in the first bat room, approximately 30 m from the cave entrance immediately after a low, narrow passage separating it from the entrance room. The specimen was found beneath a stone on guano, although not near the main guano deposits. Subsequently collected specimens were also taken from under stones.

ADDITIONAL MATERIAL: Mexico: Veracruz: Município de Tlilapan: 1 juv. ♀ ( IBUNAM), Cueva Ojo de Agua , Tlilapan, R. Sanchez, 8.II.1990 ; 1 juv. ³ ( IBUNAM), same locality, I. Vazquez, 30.III.1990, under rock ; 1 juv. ♀ ( IBUNAM), same locality, I. Vazquez, 30.III.1990, under rock, dark zone .

Typhlochactas rhodesi Mitchell, 1968 ( Figs. 1B , 3A, 3B , 4 , 5G , 7C , 9M, 9N , 12F , 32–34 ; table 8)

Typhlochactas rhodesi Mitchell, 1968: 753 , 756– 762, 771, 772, 774–777, figs. 1–21, 41, table 1, pl.

Typhlochactas rhodesi : Mitchell, 1971: 135, 138, 143, 145, 146, figs. 18–20, 24, 27; Delamare Deboutteville, 1971: 49; Reddell, 1971: 3, 27; Reddell and Mitchell, 1971: 181, 184, fig. 9; Reddell, 1973, 32, 37; Reddell and Elliott, 1973: 181; González-Sponga, 1974: 56; Soleglad, 1976: 253; Mitchell and Peck, 1977: 159, 164, 165, 167, 168; Lourenço, 1981: 660; Reddell, 1981: 37, 115, fig. 17; Francke, 1982a: 59, 60, figs. 26, 29, 34; Lourenço and Francke, 1985: 3, 5 (table 1); Francke, 1986: 5–8, figs. 14–16; Sissom, 1988: 365; Armas, 1994: 18, 21; Lourenço, 1994: 182, 183; Kovařík, 1998: 142; Sissom and Cokendolpher, 1998: 285–287 (table 1); Beutelspacher Baigts, 2000: 18, 20, 51, 52, 54, 147, 151, map 22; Sissom, 2000b: 499; Volschenk et al., 2001: 161; Soleglad and Fet, 2003b: 30, 76; Vignoli and Kovařík, 2003: 131; Lourenço et al., 2004: 1152, 1153; Sissom and Hendrixson, 2005: 123, 127, table 6.2; Lourenço and Goodman, 2008: 667; Volschenk and Prendini, 2008: 236 (table 1), 249.

Typlochactas rhodesi : Díaz Najera, 1975: 4, 32.

TYPE MATERIAL: Mexico: Tamaulipas: Município de Gómez Farias: Holotype: 1 ♀ ( AMNH), La Cueva de la Mina, Sierra de Guatemala [23 ° 069060 N 99 ° 129560W], 1600 m, R.W. and R. Mitchell, K. Pittard, D. Falls, and V. Colvin, 24.III.1967. Paratypes: 1 subad. ♀ ( AMNH), same locality, R. W. Mitchell, F. Abernethy and W. Rhodes, 29–30.VIII.1966 ; 1 ♀ ( MNHN RS 4760 ), same locality, R. W. Mitchell, F. Abernethy and W. Rhodes, 29.VIII.1967 .

DIAGNOSIS: Typhlochactas rhodesi is most closely related to T. cavicola (fig. 4). It may be separated from T. cavicola and all other Typhlochactas species by the following combination of characters. Cheliceral fixed finger with four teeth (subdistal present); median and basal teeth not fused into bicusp. Cheliceral movable finger with five dorsal teeth (two subdistals present). Carapace, anterior margin with well-developed median projection (epistome). Pedipalp chela fixed and movable fingers, median denticle row of each comprising six oblique primary subrows; basal primary subrow of movable finger considerably longer than other subrows; terminal denticle of fixed finger slightly larger than preceding denticles, fingertips interlocking evenly when closed. Legs without prolateral pedal spurs. Telotarsi without ventromedian row of spinules. Sclerites of genital operculum (♀) fused, but loosely connected by membrane along entire length of suture.

DESCRIPTION: The following description supplements the original description of Mitchell (1968) and additional data provided by Mitchell (1971) and Francke (1982 a, 1986).

Color: Carapace, pedipalp femur and patella, legs, tergites, sternites, metasoma, and telson, Yellow Ocher (123C); pedipalp chela, Pratt’s Rufous (140). Aculeus and denticle rows of pedipalp fingers darker. Larger paratype (AMNH) uniformly Buff Yellow (53); smaller paratype (MNHN) paler, except for aculeus and pedipalp finger denticles, Chamois (123D).

Chelicerae: Manus, dorsal and ventral surfaces smooth; dorsal surface with three microsetae situated near base of fixed finger; movable finger, dorsal surface with six microsetae. Fixed finger, dorsal margin with four teeth (distal, subdistal, median, and basal; fig. 5G); median and basal teeth not fused into bicusp; distal tooth largest, subdistal and median teeth equal, smaller, basal tooth smallest. Movable finger, internal distal and external distal teeth opposable, internal distal tooth completely overlapping external distal tooth in dorsal view; dorsal margin with five closely aligned teeth (internal distal, two subdistal, median, and basal), first subdistal, second subdistal and median teeth progressively increasing in size, basal tooth equal to second subdistal tooth; ventral surface with well-developed serrula, extending half length of finger; macrosetae on proximal third of finger only, not covering serrula.

Carapace: Length slightly greater than anterior width (table 8). Anterior margin sublinear to weakly convex, with small median projection (epistome) and few microsetae (fig. 32A). Posterior margin sublinear to weakly convex; asetose. Median and lateral ocelli absent. Median longitudinal and posterolateral sulci shallow; posterior transverse sulcus deep. Surface acarinate, smooth except for posterolateral margins, which are weakly granular, with scattered microsetae.

Pedipalps: Femur, dorsoexternal and ventroexternal carinae obsolete, granular; dorsointernal and ventrointernal carinae absent (fig. 34A). Dorsal and ventral surfaces mostly smooth; external and internal surfaces with scattered granules proximally; all surfaces, especially external surfaces, setose. Patella dorsoexternal carina distinct, granular; dorsointernal and ventrointernal carinae obsolete; other carinae absent. Dorsal and external surfaces less granular than femur, mostly smooth except for small granules concentrat- ed around trichobothria (figs. 34B–D); ventral and internal surfaces with small, scattered granules; ventral surface asetose. Chela longer than carapace, relatively stout, manus length greater than width (table 8); movable finger slightly longer than manus. Manus acarinate (fig. 33); internal surface with depression near base of movable finger; manus and fingers, surfaces mostly smooth with scattered setae; dorsal, external, and internal surfaces with small, scattered granules distally near base of fingers; internal surface additionally with pair of prominent, isolated granules situated close together at base of fixed finger; ventroexternal surface with small group of granules proximally. Fixed finger, median denticle row comprising six oblique primary subrows, terminal subrow shorter, basal subrow slightly longer than other subrows (fig. 9M); internal denticles larger than external denticles; terminal denticle small, equal to internal denticle, fingertips interlocking evenly when closed. Movable finger, median denticle row comprising six oblique primary subrows, terminal subrow shorter, basal subrow considerably longer than other subrows (fig. 9N); terminal denticle small.

Trichobothria: Femur with three trichobothria (fig. 34A): one external (e), one dorsal (d), one internal (i). Patella with 19 trichobothria (fig. 34B–D), five petite (d 1, d 2, et 2, esb 2, eb 2), one accessory (em 3): two ventral (v 1, v 2); 14 external (et 1 – et 3, est, em 1 – em 3, esb 1, esb 2, eb 1 – eb 5); two dorsal (d 1, d 2); one internal (i). Chela with 26 trichobothria ( Fig. 33 ), seven petite (V 1, Et 4, Et 5, Esb, Db, esb , db): 16 on manus, four ventral (V 1 – V 4), 10 external (Et 1 – Et 5, Est, Esb, Eb 1 – Eb 3), two dorsal (Db, Dt); 10 on fixed finger, four external (et, est, esb , eb), four dorsal (dt, dst, dsb, db), two internal (it, ib).

Legs: All surfaces with scattered microsetae; basitarsi with fewer setae than telotarsi. Basitarsi I–IV without prolateral pedal spurs; I and II, proventral surfaces with short subdistal row of closely aligned spinules. Telotarsi, dorsomedian lobe with one microseta; ventral surface with curved row of spinules, proximally, and six or seven submedian pairs of subspiniform macrosetae; ungues long, equal in length; dactyl short, slightly curved.

Tergites: Surfaces acarinate; I–VI, uniformly smooth; VII, mostly smooth, with few small granules posterolaterally (fig. 32A). Posteromedian surfaces with paired setae; lateral and posterior margins, especially of tergites V and VI, with microsetae.

Sternum: Posterior width equal to length (fig. 7C); apex rounded; lateral margins converging anteriorly; lateral lobes flat; posterior depression shallow. Surface with four macrosetae anteromedially and two macrosetae posterolaterally.

Genital operculum: Sclerites fused, but loosely connected by membrane along entire length of suture; anterior margins rounded (fig. 7C); microsetae situated close to median suture and posterior margins.

Pectines: Pectinal plate, surface with two macrosetae situated mediolaterally. Lamella comprising four segments (fig. 7C); surfaces covered in microsetae, larger along margins. Tooth count, 5/5; teeth oval; proximal and distal teeth slightly larger.

Sternites: Surfaces acarinate, smooth (fig. 32B). Surfaces and margins setose. Respiratory spiracles (stigmata) small, round, situated posterolaterally.

Metasoma: Segments elongated, progressively increasing in length, decreasing in width (fig. 12F), segment I width greater than length, II width equal to length, III–V length greater than width (table 8); segment V slightly shorter than carapace. Dorsosubmedian carinae, segments I–IV, obsolete, granular, distal granules not noticeably larger than preceding granules (fig. 12F). Dorsolateral carinae, segment V, obsolete, granular, present only in anterior part of segment. Dorsolateral, median lateral and ventrosubmedian carinae, segments I–IV, ventrolateral carinae, segments I–V, and ventromedian carina, segment V, absent. Dorsal intercarinal surfaces, segments I–V, slightly concave, uniformly, finely granular; other surfaces smooth. Lateral and ventral surfaces of all segments with several macrosetae.

Telson : Vesicle globose, flattened dorsally, rounded ventrally; anterodorsal lateral lobes absent (fig. 12F); surfaces smooth; ventral surface with several long and short setae. Aculeus short, slightly curved, arising gradually from vesicle.

Hemispermatophore: Male unknown.

Ontogenetic variation: Subadult similar to adults in general proportions but lacks depression and granules on pedipalp chela internal surface.

Geographical variation: All specimens from same locality.

Sexual dimorphism: Male unknown.

REMARKS: The label with the holotype indicates a different collecting date, ‘‘ 29.III. 1967,’’ to that listed in the original description ( Mitchell, 1968: 762), ‘‘ 24.III.1967.’’ The specimen listed as ‘‘depositary unknown’’ by Sissom (2000b: 499) is deposited at the AMNH. The specimen at the MNHN is damaged (probably by dehydration): the sinistral pedipalp is lost, telson dislocated, mesosoma opened and metasoma broken.

DISTRIBUTION: Known only from the type locality, La Cueva de la Mina, in the Sierra de Guatemala, Tamaulipas, Mexico (figs. 1B, 3A, 3B), a karstic region characterized by many vertical caves ranging from a few meters to more than 100 m in depth ( Mitchell, 1968; Reddell, 1981).

ECOLOGY: The holotype and paratypes of this troglobitic species were taken in a small room, about 50 m from the entrance to the cave, floored by a dark soil that apparently entered through small cracks in the overburden ( Mitchell, 1968).

Figures

Fig. 1. Map of Mexico, showing the known localities of Typhlochactidae Mitchell, 1971. A. Known localities of Alacraninae, new subfamily: Type locality of Alacran tartarus Francke, 1982, on the Huautla Plateau, Oaxaca (1); Te Cimutaá Cave, Oaxaca, a new record for the genus possibly representing a new species of Alacran Francke, 1982 (2). B. Type localities of Typhlochactinae Mitchell, 1971: Sotanochactas elliotti (Mitchell, 1971), El Sótano de Yerbaniz, San Luis Potosí (1); Stygochactas granulosus (Sissom and Cokendolpher, 1998), Sótano de Poncho, Veracruz (2); Typhlochactas cavicola Francke, 1986, Cueva del Vandalismo, Tamaulipas (3); Typhlochactas mitchelli Sissom, 1988, Cerro Ocote, Oaxaca (4); Typhlochactas reddelli Mitchell, 1968, La Cueva del Ojo de Agua de Tlilapan, Veracruz (5); Typhlochactas rhodesi Mitchell, 1968, La Cueva de la Mina, Tamaulipas (6); Typhlochactas sissomi Francke et al., 2009, Cañada de La Joya, Queretaro (7); Typhlochactas sylvestris Mitchell and Peck, 1977, 25 km S Valle Nacional, Oaxaca (8).

Fig. 4. Single most parsimonious tree (312 steps, CI: 57, RI: 56) obtained by cladistic analysis of 142 morphological characters (appendix 1) scored for nine taxa in the family Typhlochactidae Mitchell, 1971, and three outgroup taxa under weighting regimes that maximized fit and minimized length (Prendini et al., 2009). Unambiguous synapomorphies are indicated with bars. Solid bars indicate uniquely derived apomorphic states, whereas empty bars indicate parallel derivations of apomorphic states. The number above each bar gives the character number, the number below gives the character state.

Fig. 5. Typhlochactidae Mitchell, 1971, chelicerae, dorsal aspect. A. Alacran tartarus Francke, 1982, paratype ³ (AMNH). B. Sotanochactas elliotti (Mitchell, 1971), paratype ³ (WDS). C. Stygochactas granulosus (Sissom and Cokendolpher, 1998), juv. ³ holotype (AMNH). D. Typhlochactas cavicola Francke, 1986, holotype ♀ (AMNH). E. Typhlochactas mitchelli Sissom, 1988, holotype ³ (AMNH). F. Typhlochactas reddelli Mitchell, 1968, holotype ♀ (AMNH). G. Typhlochactas rhodesi Mitchell, 1968, holotype ♀ (AMNH). H. Typhlochactas sissomi Francke et al., 2009, subad. ³ holotype (IBUNAM), dextral chelicera. I. Typhlochactas sylvestris Mitchell and Peck, 1977, holotype ♀ (AMNH), sinistral chelicera. Scales: A 5 1 mm; B–H 5 0.1 mm.

Fig. 8. Typhlochactidae Mitchell, 1971, sternum, genital operculum and pectines, ventral aspect. A. Stygochactas granulosus (Sissom and Cokendolpher, 1998), juv. ³ holotype (AMNH). B. Typhlochactas mitchelli Sissom, 1988, holotype ³ (AMNH). C. Typhlochactas cavicola Francke, 1986, holotype ♀ (AMNH). D. Typhlochactas sylvestris Mitchell and Peck, 1977, holotype ♀ (AMNH). Scales 5 0.5 mm.

Fig. 9. Typhlochactidae Mitchell, 1971, dextral pedipalp chela fixed (left) and movable (right) fingers, dentition patterns. A, B. Alacran tartarus Francke, 1982. C, D. Sotanochactas elliotti (Mitchell, 1971). E, F. Stygochactas granulosus (Sissom and Cokendolpher, 1998). G, H. Typhlochactas cavicola Francke, 1986. I, J. Typhlochactas mitchelli Sissom, 1988. K, L. Typhlochactas reddelli Mitchell, 1968. M, N. Typhlochactas rhodesi Mitchell, 1968. O, P. Typhlochactas sissomi Francke et al., 2009. Q, R. Typhlochactas sylvestris Mitchell and Peck, 1977.

Fig. 12. Typhlochactinae Mitchell, 1971, metasoma and telson, lateral aspect. A. Sotanochactas elliotti (Mitchell, 1971), paratype ³ (WDS). B. Stygochactas granulosus (Sissom and Cokendolpher, 1998), juv. ³ holotype (AMNH). C. Typhlochactas cavicola Francke, 1986, holotype ♀ (AMNH). D. Typhlochactas mitchelli Sissom, 1988, holotype ³ (AMNH). E. Typhlochactas reddelli Mitchell, 1968, holotype ♀ (AMNH), segments IV, V and telson only. F. Typhlochactas rhodesi Mitchell, 1971, holotype ♀ (AMNH). G. Typhlochactas sylvestris Mitchell and Peck, 1977, holotype ♀ (AMNH). Scales 5 1 mm.

Fig. 26. Typhlochactas mitchelli Sissom, 1988, holotype ³ (AMNH), habitus. A. Dorsal aspect. B. Ventral aspect. Scale 5 1 mm.

Fig. 27. Typhlochactas mitchelli Sissom, 1988, holotype ³ (AMNH), sinistral pedipalp chela showing carinae and distribution of trichobothria. A. Dorsal aspect. B. External aspect. C. Ventral aspect. Scale 5 0.1 mm.

Fig. 28. Typhlochactas mitchelli Sissom, 1988, holotype ³ (AMNH), sinistral pedipalp femur (A) and patella (B–D) showing carinae and distribution of trichobothria. A, B. Dorsal aspect. C. External aspect. D. Ventral aspect. Scales 5 0.1 mm.

Fig. 2. Type localities and habitats of Typhlochactidae Mitchell, 1971. A, B. La Cueva del Ojo de Agua de Tlilapan (Veracruz, Mexico), type locality of Typhlochactas reddelli Mitchell, 1968: lake in front of entrance (A); entrance (B). C–F. El Sótano de Yerbaniz (San Luis Potosí, Mexico), type locality of Sotanochactas elliotti (Mitchell, 1971): entrance (C, D); descent (E); horizontal tunnel (F). Photos courtesy P. Spouse and A. G. Gluesenkamp.

Fig. 29. Typhlochactas reddelli Mitchell, 1968, holotype ♀ (AMNH), habitus. A. Dorsal aspect. B. Ventral aspect. Scale 5 1 mm.

Fig. 30. Typhlochactas reddelli Mitchell, 1968, holotype ♀ (AMNH), sinistral pedipalp chela showing carinae and distribution of trichobothria. A. Dorsal aspect. B. External aspect. C. Ventral aspect. Scale 5 0.5 mm.

Fig. 31. Typhlochactas reddelli Mitchell, 1968, holotype ♀ (AMNH), sinistral pedipalp femur (A) and patella (B–D) showing carinae and distribution of trichobothria. A, B. Dorsal aspect. C. External aspect. D. Ventral aspect. Scales 5 0.5 mm.

Fig. 3. Type localities and habitats of Typhlochactidae Mitchell, 1971. A, B. La Cueva de la Mina (Tamaulipas, Mexico), type locality of Typhlochactas rhodesi Mitchell, 1968: entrance (A); main chamber (B). C–F. Cueva de Escorpión (Oaxaca, Mexico), type locality of Alacran tartarus Francke, 1982: lake in front of entrance (C); descent (D); A. tartarus ³ (AMNH) collected from flowstone wall (E); A. tartarus ³ (AMNH) habitus, in life (F). Photos courtesy P. Spouse and A. G. Gluesenkamp.

Fig. 7. Typhlochactidae Mitchell, 1971, sternum, genital operculum and pectines, ventral aspect. A. Alacran tartarus Francke, 1982, ♀ (WDS). B. Sotanochactas elliotti (Mitchell, 1971), paratype ³ (WDS). C. Typhlochactas rhodesi Mitchell, 1968, holotype ♀ (AMNH). Scales: A 5 1 mm; B, C 5 0.5 mm.

Fig. 32. Typhlochactas rhodesi Mitchell, 1968, holotype ♀ (AMNH), habitus. A. Dorsal aspect. B. Ventral aspect. Scale 5 1 mm.

Fig. 33. Typhlochactas rhodesi Mitchell, 1968, holotype ♀ (AMNH), sinistral pedipalp chela showing carinae and distribution of trichobothria. A. Dorsal aspect. B. External aspect. C. Ventral aspect. Scale 5 0.5 mm.

Fig. 34. Typhlochactas rhodesi Mitchell, 1968, holotype ♀ (AMNH), sinistral pedipalp femur (A) and patella (B–D) showing carinae and distribution of trichobothria. A, B. Dorsal aspect. C. External aspect. D. Ventral aspect. Scales 5 0.5 mm.