Myrmecotypus Pickard-Cambridge, 1894

Silva-Junior, Cláudio J. & Bonaldo, Alexandre B., 2024, A revision of the South American species of the ant-mimicking spider genus Myrmecotypus O. Pickard-Cambridge, 1894 (Araneae: Corinnidae: Castianeirinae), Zootaxa 5555 (4), pp. 451-496 : 453

publication ID

https://doi.org/10.11646/zootaxa.5555.4.1

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scientific name

Myrmecotypus Pickard-Cambridge, 1894
status

 

Myrmecotypus Pickard-Cambridge, 1894 View in CoL

Myrmecotypus Pickard-Cambridge, 1894 View in CoL , type species by monotypy, Myrmecotypus fuliginosus Pickard-Cambridge, 1894: 123 View in CoL ; Reiskind, 1969: 270. Gender masculine.

Diagnosis. Myrmecotypus resembles Apochinomma Pavesi, 1880 and Grismadox Pett, Rubio & Perger, 2022 by the recurve posterior eye row and by the narrow carapace, differing from both by the absence of thoracic groove ( Figs 2A, 13A, 15A, 17A, B) (thoracic groove present in Apochinomma and Grismadox , see Haddad 2013: fig. 2E and Pett, Rubio & Perger 2022: fig. 12). Differs from Apochinomma by the posterior median eyes being closer to the posterior laterals than to each other ( Figs 5B, 7A, 17B, 21A; posterior eyes equidistant or posterior medians closer to each other than to the laterals in Apochinomma , see Haddad 2013: figs 4A, B), pedicel collar shorter than epigastric scutum length ( Figs 5C, 21G) (longer or nearly the length of the epigastric scutum in Apochinomma , see Haddad 2013, figs 7A, B) and by the sperm duct meander featuring more than one loop, except in M. pilosus ( Figs 3A, 6G, 14D, 22G; single loop in Apochinomma , see Haddad 2013: figs 10A, 13A). Differs from Grismadox by having only one retrolateral tibial apophysis on the male palp ( Figs 3A, 18G; two-branched retrolateral tibial apophysis in Grismadox , see Pett, Rubio & Perger 2022, figs 10, 15), by the vulvae with copulation ducts inserted laterally into the secondary spermathecae or the neck ( Figs 5H, 7D, 17E, 21I; inserted anteriorly into the secondary spermatheca in Grismadox , see Pett, Rubio & Perger 2022: figs 6, 7), and by the unmodified second pair of anterior abdominal setae ( Figs 15B, 19B, 21F; spiniform in Grismadox , see Pett, Rubio & Perger 2022, figs 8, 9).

Complementary description. Small to medium-sized spiders (3.82–8.32 mm in length); carapace orange to black; surface slightly granulate, covered with feathery hair and curved longs setae on clypeus and eye region ( Figs 8D, 11A, B, 21A, B); elongate (very elongate and narrow in M. tahyinandu Perger & Rubio, 2020 and M. rapaxoides spec. nov. ( Figs 24A, D, 7A, D), usually widest at the level of coxae II, with a depression distinguishing the cephalic and thoracic region ( Figs 4B, 14B, 14G); anterior margin of cephalic region truncate, wide, fovea absent; thoracic region dorsally swelled, generally higher than cephalic region, posterior margin usually with three slight constrictions. AER straight, almost equidistant, AME approximately three times ALE diameter, PER gently recurved and only slightly wider than AER, PME closer to PLE than to each other ( Figs 17B, 21A). Chilum absent. Cheliceral promargin with two or three teeth; retromargin with two teeth, with several long erect setae on anterior surface of paturon; endites rectangular, longer than wide, with dense maxillary hair tuft on mesal margins; labium slightly trapezoid, wider than long ( Fig. 7G). Sternum longer than wide, usually elongate, with a constriction between coxae III and IV; precoxal triangles present, intercoxal sclerites present between all coxae pairs (much wider between coxae II and III in M. tahyinandu Perger & Rubio, 2020 and M. rapaxoides spec. nov). Leg formula 4123; legs with short or medium-sized spines, tibia I ventral spination 2-2, 3-2, 3-3, 4-3, 4-4 or 5-5. Abdomen globose or oval (with a constriction only in M. lineatus , see Reiskind 1969: fig. 155; 1970: fig. 3), with a short pedicel collar ( Figs 5C, 8D, 16D, 17D), two pair of thin, unmodified anterior abdominal setae ( Fig. 19B), dorsal scutum covering almost the entire dorsal surface in males, reduced in females (except in females of M. haddadi , Fig. 4E), with feathery hairs and long surface setae; epigastric scutum present in males and females; ventral scutum present in males, absent in females; tracheal scutum present, large. Spinnerets (only females of M. haddadi , M. tahynandu and M. regianeae surveyed). Anterior lateral spinnerets with two major ampullate gland spigots in mesal margin, and several piriform gland spigots; posterior median spinnerets with three large cylindrical gland spigots, with few aciniform gland spigot and with two minor ampullate gland spigots; posterior lateral spinnerets with many small aciniform gland spigots ( Figs 5G, 7F, 17C). Male palp with a single small spiniform retrolateral tibial apophysis, absent in M. haddadi , M. niger , M. rubrofemoratus , M. formicus comb. nov., M. drogon spec. nov. M. candianii spec. nov. and M. ciriaco spec. nov.; cymbium without spines (in M. olympus , a compact field of retrolateral basal spines), tegulum usually with a retroapical tegular projection ( Figs 4G, 5I, 8G, 14D, I) and a retroapical process ( M. drogon , M. rubrofemoratus and M. formicus ) or pre-embolic ridge ( M. regianeae spec. nov. and M. tahyinandu ; Fig. 16G), sperm duct generally with four or five folds (except in M. pilosus , M. jasmineae and M. lineatus ), embolus sclerotized, generally thin, curved, devoid of grooves. Female epigyne usually with a transverse ridge, entire in M. tahyinandu , M. balerion spec. nov., M. rettenmeyeri , M. pilosus , M. dacetonoides comb. nov., M. orpheus , M. olympus and M. fuliginosus ; interrupted medially in M. lineatipes , M. niger , M. candianii spec. nov. and M. ednae spec. nov.; absent in M. haddadi and M. regiane spec. nov.; ST II globose, ST I usually narrow, undifferentiated from the neck; copulatory ducts directed medially, entering in secondary spermathecae or neck ( Figs 5H, 17E, 21I).

Haddad, C. R. (2013) A revision of the ant-like sac spider genus Apochinomma Pavesi 1881 (Araneae: Corinnidae) in the Afrotropical region. Journal of Natural History, 47, 2493 - 2529. https: // doi. org / 10.1080 / 00222933.2013.791933

Perger, R. & Rubio, G. D. (2020) Contributions to the knowledge of Neotropical ant-like spiders: Myrmecotypus tahyinandu sp. nov. from Bolivian Chiquitano forest, a new country record for M. niger, and indirect evidence for species-specific mimicry (Araneae: Corinnidae: Castianeirinae). Zootaxa, 4790 (1), 151 - 164. https: // doi. org / 10.11646 / zootaxa. 4790.1.9

Pett, B. L., Rubio, G. D. & Perger, R. (2022) Grismadox gen. nov., a new Neotropical genus of ant-resembling spiders (Araneae, Corinnidae, Castianeirinae), including the description of two new species from Bolivia and Paraguay. Zoosystematics and Evolution, 98 (1), 1 - 11. https: // doi. org / 10.3897 / zse. 98.76677

Reiskind, J. (1969) The spider subfamily Castianeirinae of North and Central America (Araneae, Clubionidae). Bulletin Museum of Comparative Zoology, 138, 163 - 325.

Kingdom

Animalia

Phylum

Arthropoda

Class

Arachnida

Order

Araneae

Family

Corinnidae