A new genus of Theraphosid spider from Mexico, with a particular palpal bulb structure (Araneae, Theraphosidae, Theraphosinae) Author Jorge I. Mendoza Author Arturo Locht Author Radan Kaderka Author Francisco medina Author Fernando Pérez-Miles text European Journal of Taxonomy 2016 2016-09-23 232 1 28 journal article 32196 10.5852/ejt.2016.232 8253f751-e408-4e55-b851-13d612f48a79 885395 52029B02-4A79-442D-8DA2-8DF3099ED8D0 Magnacarina moderata Locht , Mendoza & Medina sp. nov . urn:lsid:zoobank.org:act:74AF9502-86F8-4A92-B782-1 A50555 D8BD4 Figs 13–16 Diagnosis Magnacarina moderata sp. nov. differs from all other Magnacarina species in lacking retrolateral nodule of megaspines and having only one prolateral accessory keel well developed. Magnacarina moderata sp. nov. also differs in possessing a secondary projection that is thinner and larger that of the other species, with a short and apically directed prolateral inferior keel. Females differ in carapace distinctly larger than wide. Magnacarina moderata sp. nov. possesses the following character combination: male palpal bulb with a prominent primary projection strongly curved retrolaterally, with distal half slightly apically directed (Fig. A–C); retrolateral keel thin and slightly developed. Prolateral superior keel wide along its entire length, posterior extension ends almost in the middle of prolateral face ( Fig. 14 D–E); secondary projection is elongated and directed to apical, with one prolateral accessory keel well developed ( Fig. 14 C–D). Prolateral inferior keel wide, divided in two sections, increasing from back to front and distal end oriented to apical ( Fig. 14 A–B, D). Apical keel well developed, wider distally. Sperm pore is located between prolateral inferior and apical keels ( Fig. 14 D–E). Accessory apophysis slightly developed, bearing large megaspines at the apex ( Fig. 13 G–H). Metatarsus I lacking retrolateral nodule of megaspines ( Fig. 13 H). Spermatheca reduced, low, with one single receptacle oval in shape, strongly sclerotized. Uterus externus is three times wider, and four to five times longer than the spermatheca ( Fig. 15 E–F). Etymology The specific epithet is the latinized version of “moderate”, moderatus fem. moderata , referring to the shape of the secondary projection in the male palpal bulb which is moderately elongated and thinner than in other species. Type material Holotype MEXICO : ♂ , Nayarit , Acaponeta , 14 Nov. 1939 , coll. C.M. Bogert and H.E. Vokes ( CNAN-T1003 ) . Paratypes MEXICO : 2 ♀♀ , Sinaloa , 70 mi South of Mazatlan , 24 Jul. 1954 , coll. W.J. Gertsch ( CNAN-T1004 and AMNH ) . Description Holotype male CNAN-T1003 ( Figs 13– 14 ) Body length (not including chelicerae and spinnerets) 15.19, carapace: 7.31 long, 5.42 wide. Caput not markedly elevated; fovea procurved, 1.33 wide. Carapace with orange sheen setae ( Fig. 13 A). Eyes: anterior eye row procurved, posterior eye row, recurved. Eyes sizes and interocular distances: AME 0.24; ALE 0.32; PME 0.18; PLE 0.22; AME–AME 0.12; AME–ALE 0.08; PME–PME 0.46; PME–PLE 0.02; ALE–PLE 0.16. Ocular tubercle, width 1.18; length 0.84; clypeus 0.12 ( Fig. 13 D). Labium: length 0.90; width 1.175; with 58 cuspules. Maxilla inner corner with approximately 115-119 (left-right). Cheliceral promargin with 9-9 (left-right) teeth. Sternum length 3.07. Sigilla circular, second and third pairs hardly visible; posterior sigilla half its length from the margin ( Fig. 13 B). Leg formula: IV> I> III> II. Length of legs and palpal segments (femur, patella, tibia, metatarsus, tarsus, total): I: 5.29, 3.29, 3.41, 4.25, 2.26, 18.50; II: 4.71, 3.08, 3.33, 3.30, 2.64, 17.06; III: 4.18, 2.66, 3.03, 3.44, 2.55, 15.86; IV: 5.78, 3.13, 4.43, 4.95, 3.10, 21.39. Palp: 3.96, 2.82, 3.26, -, 1.29, 11.33. Spinnerets: PMS, 0.53 long, 0.20 apart; PLS, 0.97 basal, 0.63 middle, 1.10 distal. Tarsi I–IV scopulate, I and II divided by narrow band of setae, III and IV divided by strong band of setae. Metatarsi I scopulate on distal two thirds; II scopulate on distal half, III scopulate on distal half, and IV scopulate on distal fourth. Fig. 13. Magnacarina moderata Locht , Mendoza & Medina sp. nov., ♂, holotype (CNAN-T1003). A . Carapace, dorsal view. B . Prosoma, ventral view. C . Opisthosoma, dorsal view. D . Ocular tubercle, dorsal view. Left side: E . Metatarsus I. Prolateral view. F . Palpal tibia, dorsal view. G . Tibial apophyses, ventral view. H . Tibial apophyses, retrolateral view. Scale bars: A–C = 2 mm; E–F = 1 mm; D, G–H = 0.5 mm. Tibia I with three apophyses, prolateral apophysis with one inner larger spine ( Fig. 13 G). Retrolateral apophysis slightly curved to dorsal ( Fig. 13 G, H). Accessory apophysis slightly developed, bearing four large megaspines at its apex ( Fig. 13 H). Metatarsus I curved ( Fig. 13 E), lacking retrolateral megaspines nodule ( Fig. 13 H). Retrolateral face of palpal tibiae with a short process, slightly developed on distal half ( Fig. 13 F). Chaetotaxy (left side): femora I 1 p; II 1 p; III 1 r; IV 2 r; palp none; patellae none; tibiae I 3 p, 4v ; II 3 p, 8v ; III 2 p, 7v , 3r; IV 9v , 4r; palp none; metatarsi: I 1 p, 2v ; II 3 p, 8v ; III 3 p, 8v , 2r; IV 2 p, 8v , 2r. Palpal bulb with a prominent primary projection strongly curved retrolaterally, with distal half slightly twisted to apical (Fig. A–C). Retrolateral keel thin and slightly developed. Prolateral superior keel wide along its entire length, posterior extension ends almost in the middle of prolateral face ( Fig. 14 D–E). Secondary projection elongated with one prolateral accessory keel well developed ( Fig. 14 B, D). Prolateral inferior keel wide, divided in two sections, increasing from back to front, distal end oriented to apical ( Fig. 14 A–B, D). Apical keel well developed, wider distally. Sperm pore is located between prolateral inferior and apical keels, and opens towards prolateral face ( Fig. 14 D–E). Tegular apophysis slightly developed ( Fig. 14 A–B). Urticating setae of type III arranged in one dorsomedian patch, with copper metallic iridescence ( Fig. 13 C). Variations summarized in Table 2 . Fig. 14 . Magnacarina moderata Locht , Mendoza & Medina sp. nov., ♂, holotype (CNAN-T1003), left palpal bulb. A . Prolateral view. B . Retrolateral view. C . Dorsal view. D . Apex, dorsal view. E . Apex, apical view. White arrow indicates sperm pore. Scale bars: A–C = 1 mm; D–E = 0.5 mm. Color pattern: damaged by preservation in ethanol, carapace tegument looks yellowish; ventral coxae, labium, maxillae and sternum brown; abdomen dorsally brown with yellowish setae, ventrally brown. Urticating setae with copper metallic iridescence. Legs and palps: brownish. Paratype female CNAN-T1004 ( Fig. 15 A–E) Body length (not including chelicerae and spinnerets) 14.50, carapace: 6.85 long, 5.60 wide. Caput not markedly elevated; fovea procurved, 1.17 wide. Carapace with orange sheen setae ( Fig. 15 A). Eyes: anterior eye row procurved, posterior eye row, recurved. Eyes sizes and interocular distances:AME 0.225; Fig. 15. Magnacarina moderata Locht , Mendoza & Medina sp. nov. A–E . ♀, paratype (CNAN-T1004). A . Carapace, dorsal view. B . Prosoma, ventral view. C . Opisthosoma, dorsal view. D . Ocular tubercle, dorsal view. E . Spermatheca, ventral view. F . ♀, paratype (AMNH), spermatheca, ventral view. Scale bars: A–C = 2 mm; E–F = 1 mm; D = 0.5 mm. ALE 0.35; PME: 0.125; PLE: 0.275; AME–AME: 0.175; AME–ALE: 0.075; PME–PME: 0.55; PME– PLE: 0.025; ALE–PLE: 0.10. Ocular tubercle, width 1.225; length 0.95; clypeus lacking ( Fig. 15 D). Labium: length 0.93; width 1.50; with 62 cuspules. Maxilla inner corner with approximately 134-123 (left-right). Cheliceral promargin with 9-9 (left-right) teeth. Sternum circular, length 3.10. Sigilla oval, second and third pair hardly visible; posterior sigilla once its length from the margin ( Fig. 15 B). Leg formula: IV> I> II> III. Length of legs and palpal segments (femur, patella, tibia, metatarsus, tarsus, total): I: 4.75, 3.17, 3.44, 2.53, 2.28, 16.17; II: 4.11, 2.93, 2.55, 2.39, 2.36, 14.34; III: 3.46, 2.43, 2.45, 2.90, 2.24, 13.48; IV: 4.99, 2.82, 3.85, 4.16, 3.05, 18.87. Palp: 3.43, 2.43, 2.29, -, 2.79, 10.94. Spinnerets: PMS, 0.87 long, 0.43 apart; PLS, 1.63 basal, 0.90 middle, 1.03 distal. Tarsi I–IV densely scopulate, I and II divided by narrow band of setae, III and IV divided by strong band of setae. Metatarsi I densely scopulate; II scopulate on distal two thirds, III scopulate on distal half, and IV scopulate on distal fourth. Chaetotaxy (left side): femora I 1 p; II 1 p; III 1 p, 1r; IV 1 r; palp 1p; patellae none; tibiae II 1v ; III 2 p, 4v , 2r; IV 5v , 2r; palp 3v ; metatarsi I 2v ; II 4v ; III 3 p, 7v , 2r; IV 3 p, 9v , 2r. Spermatheca fused, low with one single receptacle oval in shape, strongly sclerotized. Uterus externus is three times wider, and four to five times longer than the spermatheca ( Fig. 15 E–F). Urticating setae of type III, arranged in one dorsomedian patch, with copper metallic iridescence ( Fig. 15 C). Variations summarized in Table 2 . Color pattern: damaged by preservation in ethanol, carapace tegument looks yellowish; ventral coxae, labium, maxillae and sternum brown; abdomen dorsally brown with yellowish setae, ventrally brown. Urticating setae with copper metallic iridescence. Legs and palps: brownish. Distribution Known only from the border area between the states of Nayarit and Sinaloa ( Fig. 16 ), this species inhabits scrapes under rocks in deciduous forest.