Thunberga, Jäger, 2020

Jäger, Peter, 2020, Thunberga gen. nov., a new genus of huntsman spiders from Madagascar (Araneae: Sparassidae: Heteropodinae), Zootaxa 4790 (2), pp. 245-260 : 246-247

Thunberga gen. nov.

Type species. Thunberga nossibeensis ( Strand, 1907) comb. nov.

Etymology. Named after Greta Thunberg (* 2003 in Sweden), a young and courageous climate activist fighting against global warming, ignorant stakeholders and for a better future on our planet. In fact, global warming and other issues caused by humans affect all parts of the nature including Madagascar’s nature in general and its spider fauna in particular. Gender is feminine.

Diagnosis. Thunberga gen. nov. belongs to the Heteropodinae Thorell (see also discussion) but is distinguished from other Asian and African genera of this subfamily as well as from Anaptomecus Simon, 1903b by having more than 4 retromarginal cheliceral teeth ( Fig. 5 ), AME equal in size to ALE or very slightly larger, and posterior eye row straight or slightly procurved ( Fig. 4 ) (other Asian and African genera of Heteropodinae with 4 retromarginal cheliceral teeth, lateral eyes larger and both eye rows recurved). The new genus is distinguished from other South American genera ( Guadana Rheims, 2010 , Sparianthina Banks, 1929 having at least in some species more than 4 retromarginal cheliceral teeth) by the anterior eye row straight to procurved (recurved in the American genera). Moreover, there is a small but consistent gap between the two distal retromarginal and the remaining teeth ( Figs 5 , 13 , 21 : arrows). This character seems to be unique in the entire family.

In general, colouration pattern is not a good diagnostic character. However, most Thunberga spiders have a characteristic pattern of dots on their prosoma ( Figs 44, 46 ), which has not been observed in any of the genera of this family so far.

Description. Medium sized to very large Sparassidae (body length males 12.7–24.0, females: 10.4–31.0) with laterigrade legs. Eye rows, when viewed from dorsal, straight to slightly recurved (anterior eyes) and slightly procurved (posterior eyes); AME, ALE, PME roughly equally large, PLE in most species slightly larger; lateral eyes on small humps ( Figs 4 , 12 , 19 ). Promargin of chelicerae with 3, retromargin with 5–7 teeth, cheliceral furrow close to promarginal teeth with 26–50 denticles, in most cases in distinct patch, in few cases with few denticles extending in a row a bit distally ( Figs 5 , 13 , 21 ). Retromargin of chelicerae close to fang base with 1–4 bristles. Leg formula: 2143. Scopulae on tarsi and metatarsi I–III dense, sparse in metatarsus IV. Trilobate membrane with moderately distinct median hook and lateral projections ( Figs 16 , 22 ). Palpal claw of female palp with 6 moderately long teeth ( Fig. 14 ), leg claws with 12 uniserial teeth ( Fig. 15 ). Sternum longer than wide, with 4 pairs of short projections pointing to coxae. Gnathocoxae with uniserial serrula in usual position and of normal length (i.e. not reduced as in May Jäger & Krehenwinkel, 2015).

Opisthosoma oval, dorsally with two pairs of muscle sigilla, the latter partly elongated, ventrally with two rows of small muscle sigilla, more or less parallel, posteriorly converging ( Figs 7 , 32–33, 35–36, 38–39 , 41–42, 44–45 ).

Palp with cymbium two times longer than wide, RTA arising distally from tibia, simple, straight. Spermophor running from disto-retrolateral part of tegulum proximally, then into a proximo-prolateral loop before entering the embolus ( Figs 1–3 , 17–18 ).

Epigyne with epigynal field longer than wide, with anterior pocket in its very anterior part, opening posteriad, with one pair of slit sensilla (in some cases reduced) close to the epigynal field medially; with lateral bands (muscle attachment fields) situated medially beside epigynal field (not anterior to the field as in most other genera) ( Figs 8, 11 , 23 , 26, 29 ). Internal duct system with wider epigynal folds running from anterior to posterior, then narrowing to tubular duct system, finally running into fertilisation ducts postero-para-medially ( Figs 9 , 24 , 27, 30 ).

Colouration: Yellowish-brown with moderately distinct pattern, mostly consisting of small dots on dorsal prosoma (especially along striae), opisthosoma and parts of legs (especially femora), chelicerae with longitudinal stripes ( Figs 6 , 20 , 32–46 ).

Species included. Thunberga greta spec. nov., T. malagassa ( Strand, 1907) comb. nov., T. nossibeensis ( Strand, 1907) comb. nov., T. septifer ( Strand, 1908) comb. nov.

Natural History. Nothing is known so far about the natural history of species of this new genus. No information on labels were available either. Roger (2018: fig. 20d) published a photo of a spider most likely belonging to Thunberga gen. nov. If so, it might well be that those spiders are nocturnal hunters in the foliage (Roger mentions ylang-ylang trees in Combani).

Distribution. Madagascar and neighbouring islands (St. Marie, Nosy Be) ( Fig. 47 ), most likely occurring also on Mayotte (see Roger 2018: fig. 20d).

Figures

FIGURE 47. Map of Madagascar with currently known localities of Thunberga spp.: red circles—T. nossibeensis comb. nov., yellow square—T. malagassa comb. nov., blue square—T. septifer comb. nov., green triangles—T. greta spec. nov.

FIGURES 1–7. Thunberga nossibeensis (Strand, 1907) comb. nov., male from Madagascar, SMF 4694. 1–3 Right palp, mirrored (1 prolateral, 2 ventral, 3 retrolateral); 4 Eyes, dorsal; 5–6 Left chelicera (5 margin, ventral; 6 frontal); 7 Opisthosoma, dorsal (modified from Jäger & Kunz 2005). C—conductor, E—embolus, RTA—retrolateral tibial apophysis, SP—spermophor. Arrow pointing to gap between the two distal retromarginal teeth and proximal ones.

FIGURES 8–16. Thunberga nossibeensis (Strand, 1907) comb. nov. from Madagascar (8–10, 12–16 female syntype of T. hildebrandti comb. nov.; 11 female from St. Marie, MNHN 19484). 8–11 Copulatory organ (8, 11 epigyne, ventral; 9 vulva, dorsal; 10 schematic course of internal duct system, dorsal); 12 Eyes, dorsal; 13 Margin of left chelicera; 14 Palpal claw, lateral; 15 Leg claw, lateral; 16 trilobate membrane, dorsal (8–10, 12–13 modified from Jäger & Kunz 2005). AP—anterior pocket, EF—epigynal field, FD—fertilisation ducts, FW—first winding of internal duct system, GA—glandular appendages, LB—lateral band of epigynal field, LL—lateral lobes, MS—median septum, TP—turning point of internal duct system. Arrow pointing to gap between the two distal retromarginal teeth and proximal ones.

FIGURES 17–22. Thunberga malagassa (Strand, 1907) comb. nov., male from Madagascar, SMF 4692. 17–18 Left palp (17 ventral, 18 retrolateral); 19 Eyes, dorsal; 20 Prosoma, frontal; 21 Margin of left chelicera, ventral; 22 trilobate membrane, dorsal (17–20 modified from Jäger & Kunz 2005). C—conductor, E—embolus. Arrow pointing to gap between the two distal retromarginal teeth and proximal ones.

FIGURES 41–46. Thunberga spp. from Madagascar, habitus. 41–43 T. septifer (Strand, 1908) comb. nov., female holotype, NHRS 324; 44–46 T. greta spec. nov., female paratype, PJ 3683, ex MNHN 19650, SMF. 41, 44 dorsal; 42, 45 ventral; 43, 46 frontal.

FIGURES 32–40. Thunberga spp. from Madagascar, habitus. 32–34 T. nossibeensis (Strand, 1907) comb. nov., male, PJ 3698, NHRS; 35–37 T. nossibeensis (Strand, 1907) comb. nov., female, PJ 3699, NHRS; 38–40 T. malagassa (Strand, 1907) comb. nov., male, SMF 4692. 32, 35, 38 dorsal; 33, 36, 39 ventral; 34, 37, 40 frontal.

FIGURES 23–25. Thunberga septifer (Strand, 1908) comb. nov., holotype male from Madagascar, NHRS 324. Copulatory organ (23 epigyne ventral, 24 vulva dorsal, 25 schematic course of internal duct system dorsal).AP—anterior pocket, FW—first winding of internal duct system, GA—glandular appendages, LB—lateral band of epigynal field, MS—median septum, SSslit sensillum, TP—turning point of internal duct system.

FIGURES 26–31. Thunberga greta spec. nov. from Madagascar (26–28 holotype female, MHNN 19650; 29–31 female paratype, MNHN 19462). Copulatory organ (26, 29 epigyne ventral, 27, 30 vulva dorsal, 28, 31 schematic course of internal duct system dorsal).AP—anterior pocket, FW—first winding of internal duct system, GA—glandular appendages, LB—lateral band of epigynal field, MS—median septum, SS—slit sensillum, TP—turning point of internal duct system.