Tliltocatl, 2020

Mendoza, Jorge & Francke, Oscar, 2020, Systematic revision of Mexican threatened tarantulas Brachypelma (Araneae: Theraphosidae: Theraphosinae), with a description of a new genus, and implications on the conservation, Zoological Journal of the Linnean Society 188, pp. 82-147 : 131-134

TLILTOCATL MENDOZA & FRANCKE , GEN. NOV.

( FIGS 39–44)

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Type species: Eurypelma vagans Ausserer, 1875 , herein designated.

Species included: Tliltocatl albopilosum ( Valerio, 1980) , comb. nov., Tliltocatl epicureanum ( Chamberlin, 1925) , comb. nov., Tliltocatl kahlenbergi ( Rudloff, 2008) , comb. nov., Tliltocatl sabulosum (F. O. Pickard-Cambridge, 1897) , comb. nov., Tliltocatl schroederi ( Rudloff, 2003) , comb. nov., Tliltocatl vagans ( Ausserer, 1875) , comb. nov., Tliltocatl verdezi ( Schmidt, 2003) , comb. nov.

Diagnosis

The new genus Tliltocatl can be distinguished from all other known theraphosinae genera (except Brachypelma ) by the following character combination: (1) having just claviform stridulating setae on the prolateral face of leg I trochanter/femur and retrolateral face trochanter of the palp; (2) both sexes possess always urticating setae types I and III – type III are located in the dorsoposterior area and type I surrounding these; (3) the male palpal bulb distally wide and flattened (spoon-shaped) and has prolateral superior and apical keels united at the apex ( Figs 39C, D, 40C–F), prolateral superior and prolateral inferior keels are at similar height, joined at their distal end and widely separating towards the embolus base (better seen in dorsal position) ( Fig. 39F), the prolateral inferior keel is similar in length or longer than the prolateral superior ( Fig 39E), the apical keel can extend widely to backwards just as the prolateral inferior keel and usually is broader on its distal half ( Figs 39D, E; 40B, D–F); (4) females have a single fused spermatheca, apically narrowed ( Figs 39G–H, 41A); (5) spermathecal baseplate absent or slightly developed, poorly sclerotized ( Fig. 39H); (6) both sexes lack a plumose pad of setae on leg IV femur; and (7) all tarsi scopulae are undivided. It differs from Brachypelma by the coloration of legs, which are black ( Figs 42, 43B–D) or have long, whitish setae (as T. albopilosum , Fig. 43A) in combination with a dark carapace and long red/yellowish setae on abdomen ( Figs 42, 43B–D). The shape of genitalia also differs in both sexes with the male palpal bulb apex larger than in Brachypelma and by the presence of prolateral inferior keel well developed and posteriorly extended ( Figs 39A, D–F, 40A, D, E). The apical keel is also larger than in Brachypelma ( Figs 30D, 33D) and wider on distal half ( Figs 39B, D, E, 40B, D, E). Embolus is regularly similar in length or longer than the tegulum ( Figs 39C–D, 40C–F), whereas in Brachypelma it is shorter ( Fig. 10D). It also differs in having spination on the patellae of palps and legs. Females differs in the spermatheca apex inwardly curved and by lacking spermathecal baseplate ( Fig. 39G) or poorly sclerotized and widely separated when present ( Fig. 39H).

Description

Carapace regularly as long as wide, caput slightly elevated ( Figs 42, 43). Cephalic striae inconspicuous ( Fig. 43A). Fovea deep, straight or recurve. Eye tubercle distinct and raised, wider than long. Anterior eye row procurved, posterior eye row recurved. Clypeus narrow or absent. Labium subtrapezoidal, wider than long, with 85–120 cuspules on anterior third centre. Maxilla subrectangular, anterior lobe distinctly produced into conical process, inner corner with 130–220 cuspules. Sternum longer than wide. Anterior pair of sigillae circular and slightly seen, second pair oval enlarged, posterior pair oval or rounded, generally once its length from the sternum margin. Leg formula: I, II, III, IV. Tarsi I–IV fully scopulated. All tarsi scopulae are undivided. Metatarsi I–II fully scopulated. Metatarsus III is 50% distally scopulated and metatarsus IV is 20–40% distally scopulated. The femur of leg III is slightly enlarged but not swollen as in other genera. Femora IV without retrolateralscopulae.Claviformstridulatingsetaeonpalp trochanter retrolateral face and in leg I trochanter and femur prolateral face. Patellae of the legs have at least one spine on prolateral or retrolateral side. Posterior lateral spinneret distally elongating, digitiform. Both sexes possess urticating setae type I and type III; Type III are located in the dorsoposterior area and type I surrounding these. Males possess two tibial apophysis, retrolateral apophysis slightly curved in apically. Globous bulb with small subtegulum longer than its height. Embolus flattened ( Fig. 39A, B), longer than tegulum ( Fig. 39C, D), with prolateral superior and apical keel large, joint at the embolus tip forming a typical spoon-shape ( Figs 39C–E, 40C–F). Prolateral inferior keel well developed, parallel to prolateral superior and larger in general ( Figs 39D– F, 40A, D, E). Females with a simple undivided/fused spermatheca apically narrowed and medially curved inwardly ( Fig. 39G, H). Spermathecal baseplate absent or slightly developed ( Fig. 39H). Spermatheca midwidth shorter than its base and well sclerotized ( Fig. 39G, H). Most of the species are black with long, red setae on the opisthosoma (except T. albopilosum , T. schroederi and T. verdezi ) ( Figs 42–43). Juveniles are similar in colour to the adults but paler.

Remarks

Tliltocatl can be confused by unexperienced people with Sericopelma spp. due to the similar coloration, but they can be easily differentiated from each other, because adult males of Sericopelma lack tibial apophysis, the female spermatheca of Sericopelma is strongly sclerotized ( Fig. 41B), also the spermatheca is distinctly swollen on the apex showing a P-shape (better seen laterally). In addition, Sericopelma has a distinct radiating sulcus on the carapace ( Gabriel & Longhorn, 2015).

Etymology

The genus gender is masculine. The name is a noun in apposition comprising the Nahuatl words Tlil, which means ‘black’, and tocatl, which means ‘spider’, referring to the black coloration of species in the genus.

Distribution

Tliltocatl occurs in Mexico, Guatemala, Belize, Honduras, El Salvador, Nicaragua and Costa Rica ( Fig. 44). The species of the genus are found in deciduous forest, evergreen rain forest and grasslands along the Pacific coast, Mexican Gulf and Atlantic Coast. Specimens live inside burrows under flat rocks, fallen logs, sidehills, tree roots and even some species dig burrows in farmlands, gardens or close to flooded land.