Abstract
The members of the trachelid spider genus Trachelas L. Koch, 1872 are taxonomically revisited in the Americas, and the fauna from southern South America is revised. The new genus Neochelas is diagnosed and described to accommodate these species, as well as six new species and 61 transferred species, making Neochelas the most diverse genus of trachelids with 67 nominal taxa. Four species are redescribed: N. robustus (Keyserling, 1891) comb. nov., N. rugosus (Keyserling, 1891) comb. nov., N. submissus (Gertsch, 1942) comb. nov., and N. vitiosus (Keyserling, 1891) comb. nov.; the males of N. submissus are described for the first time. Six new species are described from Argentina, Brazil, and Paraguay: N. amambay sp. nov., N. cerroleon sp. nov., N. calilegua sp. nov., N. gualamba sp. nov., N. iguazu sp. nov., and N. itapua sp. nov. Neochelas niger (Mello-Leitão, 1922) comb. nov. and Neochelas tridentatus (Mello-Leitão, 1947) comb. nov. are transferred from Trachelas and considered nomina dubia due to insufficient descriptions and descriptions based on immature specimens; their types are illustrated here. The remaining new combinations proposed (from Trachelas to Neochelas) are the following: Neochelas amacayacu (Sherwood & Arzuza Buelvas, 2025), Neochelas anomalus (Taczanowski, 1874), Neochelas barroanus (Chamberlin, 1925), Neochelas bicolor (Keyserling, 1887), Neochelas bispinosus (F. O. Pickard-Cambridge, 1899), Neochelas borinquensis (Gertsch, 1942), Neochelas bravidus (Chickering, 1973), Neochelas bulbosus (F. O. Pickard-Cambridge, 1899), Neochelas cadulus (Chickering, 1973), Neochelas cambridgei (Kraus, 1955), Neochelas contractus (Platnick & Shadab, 1974), Neochelas crassus (Rivera-Quiroz & Alvarez-Padilla, 2015), Neochelas daubei (Schmidt, 1971), Neochelas depressus (Platnick & Shadab, 1974), Neochelas digitus (Platnick & Shadab, 1974), Neochelas dilatus (Platnick & Shadab, 1974), Neochelas ductonada (Rivera-Quiroz & Alvarez-Padilla, 2015), Neochelas ecudobus (Chickering, 1973), Neochelas erectus (Platnick & Shadab, 1974), Neochelas femoralis (Simon, 1898), Neochelas fuscus (Platnick & Shadab, 1974), Neochelas giganteus (Platnick & Shadab, 1974), Neochelas gloriamarielae (Chamé-Vázquez & Chamé-Vázquez, 2025), Neochelas hamatus (Platnick & Shadab, 1974), Neochelas hassleri (Gertsch, 1942), Neochelas huachucanus (Gertsch, 1942), Neochelas inclinatus (Platnick & Shadab, 1974), Neochelas jamaicensis (Gertsch, 1942), Neochelas lanceolatus (F. O. Pickard-Cambridge, 1899), Neochelas latus (Platnick & Shadab, 1974), Neochelas mexicanus (Banks, 1898), Neochelas mombachensis (Leister & Miller, 2015), Neochelas mulcetus (Chickering, 1973), Neochelas oculus (Platnick & Shadab, 1974), Neochelas odoreus (Rivera-Quiroz & Alvarez-Padilla, 2015), Neochelas organatus (Platnick & Shadab, 1974), Neochelas pacificus (Chamberlin & Ivie, 1935), Neochelas panamanus (Chickering, 1937), Neochelas parallelus (Platnick & Shadab, 1974), Neochelas planus (Platnick & Shadab, 1974), Neochelas prominens (Platnick & Shadab, 1974), Neochelas quadridens (Kraus, 1955), Neochelas rotundus (Platnick & Shadab, 1974), Neochelas santaemartae (Schmidt, 1971), Neochelas similis (F. O. Pickard-Cambridge, 1899), Neochelas sinuosus (Platnick & Shadab, 1974), Neochelas speciosus (Banks, 1898), Neochelas spicus (Platnick & Shadab, 1974), Neochelas spinulatus (F. O. Pickard-Cambridge, 1899), Neochelas spirifer (F. O. Pickard-Cambridge, 1899), Neochelas tomaculus (Platnick & Shadab, 1974), Neochelas tranquillus (Hentz, 1847), Neochelas transversus (F. O. Pickard-Cambridge, 1899), Neochelas triangulus (Platnick & Shadab, 1974), Neochelas trifidus (Platnick & Shadab, 1974), Neochelas truncatulus (F. O. Pickard-Cambridge, 1899), and Neochelas volutus (Gertsch, 1935). Finally, we propose the new combination Trachelopachys nigrifemur (Mello-Leitão, 1941) comb. nov., transferred from Trachelas. After this study, we propose that Trachelas does not occur in the Americas. We present a phylogenetic analysis of Trachelidae based on six genetic markers, confirming the monophyly of Neochelas and showing that it is not closely related to Trachelas sensu stricto.
References
- Arakawa, K., Kono, N., Malay, A.D., Tateishi, A., Ifuku, N., Masunaga, H., Sato, R., Tsuchiya, K., Ohtoshi, R., Pedrazzoli, D. & Shinohara, A. (2022) 1000 spider silkomes: Linking sequences to silk physical properties. Science Advances, 8 (41), eabo6043. https://doi.org/10.1126/sciadv.abo6043
- Azevedo, G.H.F., Parreiras, J.S., Bougie, T., Michalik P., Wunderlich, J., Ramírez, M.J. (2021) Fossils constrain biogeographic history in a clade of flattened spiders with transcontinental distribution. Journal of Biogeography, 48, 3032–3046. https://doi.org/10.1111/jbi.14259
- Azevedo, G.F., Bougie, T., Carboni, M., Hedin M. & Ramírez, M.J. (2022) Combining genomic, phenotypic and Sanger sequencing data to elucidate the phylogeny of the two-clawed spiders (Dionycha). Molecular Phylogenetics and Evolution, 166, 107327. https://doi.org/10.1016/j.ympev.2021.107327
- Banks, N. (1891) Notes on some spiders described by Hentz. Entomological News, 2, 84–87.
- Banks, N. (1898) Arachnida from Baja California and other parts of Mexico. Proceedings of the California Academy of Sciences, Series 3, 1 (7), 205–309.
- Banks, N. (1909) Arachnida from Costa Rica. Proceedings of the Academy of Natural Sciences of Philadelphia, 61, 194–234.
- Bosselaers, J. & Bosmans, R. (2010) Studies in Corinnidae (Araneae): a new Paratrachelas Kovblyuk & Nadolny from Algeria, as well as the description of a new genus of Old World Trachelinae. Zootaxa, 2612 (1), 41–56. https://doi.org/10.11646/zootaxa.2612.1.3
- Bosselaers, J., Urones, C., Barrientos, J.A. & Alberdi, J.M. (2009) On the Mediterranean species of Trachelinae (Araneae, Corinnidae) with a revision of Trachelas L. Koch 1872 on the Iberian Peninsula. Journal of Arachnology, 37 (1), 15–38. https://doi.org/10.1636/a08-33.1
- Briscoe, A.G., Goodacre, S., Masta, S.E., Taylor, M.I., Arnedo, M.A., Penney, D., Kenny, J. & Creer, S. (2013) Can long-range PCR be used to amplify genetically divergent mitochondrial genomes for comparative phylogenetics? A case study within spiders (Arthropoda: Araneae). PLoS One, 8, e62404. https://doi.org/10.1371/journal.pone.0062404
- Bryant, E.B. (1933) New and little known spiders from the United States. Bulletin of the Museum of Comparative Zoology, 74, 171–193.
- Bryant, E.B. (1940) Cuban spiders in the Museum of Comparative Zoology. Bulletin of the Museum of Comparative Zoology, 86, 247–532.
- Camargo, H.F. de A. (1953) Sobre algumas aranhas que ocorrem no Brasil, com descrição de um alótipo (Arachnida-Araneae). Papéis Avulsos do Departamento de Zoologia, Secretaria de Agricultura, São Paulo, 11, 301–340. https://doi.org/10.11606/0031-1049.1953.11p301-340
- Chamberlin, R.V. (1925) Diagnoses of new American Arachnida. Bulletin of the Museum of Comparative Zoology, 67, 209–248.
- Chamberlin, R.V. & Ivie, W. (1935) Miscellaneous new American spiders. Bulletin of the University of Utah, 26 (4), 1–79.
- Chamé-Vázquez, D. & Chamé-Vázquez, E.R. (2025) A new species of Trachelas L. Koch, 1872 belonging to the tranquillus species group (Araneae: Trachelidae) from southern Mexico. Zootaxa, 5683 (2), 294–300. https://doi.org/10.11646/zootaxa.5683.2.9
- Chickering, A.M. (1937) The Clubionidae of Barro Colorado Island, Panama. Transactions of the American Microscopical Society, 56 (1), 1–47. https://doi.org/10.2307/3222720
- Chickering, A.M. (1973) The spider genus Trachelas (Araneae, Clubionidae) in the West Indies. Psyche, Cambridge, 79 (3), 215–230. [1972] https://doi.org/10.1155/1972/48060
- Gertsch, W.J. (1935) New American spiders with notes on other species. American Museum Novitates, 805, 1–24.
- Gertsch, W.J. (1942) New American spiders of the family Clubionidae III. American Museum Novitates, 1195, 1–18.
- Gómez-Moreno, K.G., Chamé-Vázquez, D. & Jiménez, M.-L. (2023) Contribución al conocimiento de las arañas (Arachnida: Araneae) en Sonora, Noroeste de México. Acta Zoológica Mexicana, Nueva Serie, 39 (1), 3912583. https://doi.org/10.21829/azm.2023.3912583
- Grismado, C.J. (2004) Una nueva especie del género Meriola Banks de Argentina (Araneae, Corinnidae, Trachelinae). Revista Ibérica de Aracnología, 10, 233–235.
- González Márquez, M.E., Grismado, C.J. & Ramírez, M.J. (2021) A taxonomic revision of the spider genus Meriola Banks (Araneae: Trachelidae). Zootaxa, 4936 (1), 1–113. https://doi.org/10.11646/zootaxa.4936.1.1
- Haddad, C.R. (2025) And they just keep coming: four new genera of dark sac spiders from southern Africa (Araneae, Trachelidae). African Invertebrates, 66, 19–64. https://doi.org/10.3897/AfrInvertebr.66.139299
- Haddad, C.R., Jin, C., Platnick, N.I. & Booysen, R. (2021) Capobula gen. nov., a new Afrotropical dark sac spider genus related to Orthobula Simon, 1897 (Araneae: Trachelidae). Zootaxa, 4942 (1), 41–71. https://doi.org/10.11646/zootaxa.4942.1.2
- Haddad, C.R. & Lyle, R. (2025) A revision of the genus Trachelas L. Koch, 1872 (Araneae: Trachelidae) in the continental Afrotropical Region. Zootaxa, 5673 (4), 451–493. https://doi.org/10.11646/zootaxa.5673.4.1
- Hentz, N.M. (1847) Descriptions and figures of the araneides of the United States. Boston Journal of Natural History, 5 (4), 443–479, pls. 23–24 + 30–31.
- Hoang, D.T., Chernomor, O., von Haeseler, A., Minh, B.Q. & Vinh, L.S. (2018) UFBoot2: Improving the ultrafast bootstrap approximation. Molecular Biology and Evolution, 35, 518–522. https://doi.org/10.1093/molbev/msx281
- Jiménez, M.-L., Chamé-Vázquez, D. & Palacios-Cardiel, C. (2022) New records of spiders (Arachnida: Araneae) from the Madrean Archipelago of Sonora, Mexico. Pan-Pacific Entomologist, 98 (3), 196–204. https://doi.org/10.3956/2022-98.3.196
- Jin, C., Yin, X.C. & Zhang, F. (2017) Four new species of the genus Trachelas L. Koch, 1872 and the first record of T. vulcani Simon, 1896 from south-west China (Araneae: Trachelidae). Zootaxa, 4324 (1), 23–49. https://doi.org/10.11646/zootaxa.4324.1.2
- Kalyaanamoorthy, S., Minh, B.Q., Wong, T.K.F., von Haeseler, A., & Jermiin, L.S. (2017) ModelFinder: Fast model selection for accurate phylogenetic estimates. Nature Methods, 14, 587–589. https://doi.org/10.1038/nmeth.4285
- Keyserling, E. (1887) Neue Spinnen aus America. VII. Verhandlungen der Kaiserlich-Königlichen Zoologisch-Botanischen Gesellschaft in Wien, 37, 421–490, pl. 6.
- Keyserling, E. (1891) Die Spinnen Amerikas. Brasilianische Spinnen. Dritter Band. Bauer & Raspe, Nürnberg, 278 pp, 10 pls. https://doi.org/10.5962/bhl.title.64832
- Kraus, O. (1955) Spinnen aus El Salvador (Arachnoidea, Araneae). Abhandlungen der Senckenbergischen Naturforschenden Gesellschaft, 493, 1–112.
- Leister, M. & Miller, K.B. (2015) Description of a new tracheline spider, Trachelas mombachensis sp. n., in the T. bispinosus species group from the Mombacho Volcano in Nicaragua (Araneae: Trachelidae). Zootaxa, 3936 (1), 141–146. https://doi.org/10.11646/zootaxa.3936.1.9
- Mello-Leitão, C.F. de (1922) Novas clubionidas do Brasil. Archivos da Escola Superior de Agricultura e Medicina Veterinaria, Rio de Janeiro, 6, 17–56.
- Mello-Leitão, C.F. de (1941) Catalogo das aranhas da Colombia. Anais da Academia Brasileira de Ciências, 13, 233–300.
- Mello-Leitão, C.F. de (1947) Aranhas de Carmo do Rio Claro (Minas Gerais) coligidas pelo naturalista José C. M. Carvalho. Boletim do Museu Nacional do Rio de Janeiro, Nova Série, Zoologia, 80, 1–34.
- Minh, B.Q., Schmidt, H.A., Chernomor, O., Schrempf, D., Woodhams, M.D., von Haeseler, A. & Lanfear, R. (2020) IQ-TREE 2: New models and efficient methods for phylogenetic inference in the genomic era. Molecular Biology and Evolution, 37 (5), 1530–1534. https://doi.org/10.1093/molbev/msaa015
- Petrunkevitch, A. (1930) The spiders of Porto Rico. Part three. Transactions of the Connecticut Academy of Arts and Sciences, 31, 1–191.
- Pickard-Cambridge, F.O. (1899) Arachnida - Araneida and Opiliones. Vol. 2. Published for the editors by R.H. Porter and Dulau & Co., London, 48 pp., 5 pls. [pp. 41–88, pls. 2–6]
- Piñánez Espejo, Y.M.G., Munévar, A. & Kochalka, J.A. (2022) A new species of Orthobula Simon, 1897 (Araneae: Trachelidae) from South America. Zootaxa, 5124 (1), 75–80. https://doi.org/10.11646/zootaxa.5124.1.5
- Platnick, N.I. (1975) A revision of the South American spider genus Trachelopachys (Araneae, Clubionidae). American Museum Novitates, 2589, 1–25.
- Platnick, N.I. (2000) The tracheline spider genus Paccius (Araneae, Corinnidae) in the Parc National de Marojejy, Madagascar. Fieldiana Zoology, New Series, 97, 115–121.
- Platnick, N.I. & Ewing, C. (1995) A revision of the tracheline spiders (Araneae, Corinnidae) of southern South America. American Museum Novitates, 3128, 1–41.
- Platnick, N.I. & Shadab, M.U. (1974a) A revision of the tranquillus and speciosus groups of the spider genus Trachelas (Araneae, Clubionidae) in North and Central America. American Museum Novitates, 2553, 1–34.
- Platnick, N.I. & Shadab, M.U. (1974b) A revision of the bispinosus and bicolor groups of the spider genus Trachelas (Araneae, Clubionidae) in North and Central America and the West Indies. American Museum Novitates, 2560, 1–34.
- Ramírez, M.J. (2014) The morphology and phylogeny of dionychan spiders (Araneae: Araneomorphae). Bulletin of the American Museum of Natural History, 390, 1–374. https://doi.org/10.1206/821.1
- Ramírez, M.J. & Grismado, C.J. (2024) Paranita, a new genus of spiders from northeastern Argentina (Araneae, Trachelidae). Revista del Museo Argentino de Ciencias Naturales, Nueva Serie, 26 (1), 47–68. https://doi.org/10.22179/REVMACN.26.824
- Rivera-Quiroz, F.A. & Álvarez-Padilla, F. (2015) Three new species of the genus Trachelas (Araneae: Trachelidae) from an oak forest inside the Mesoamerican biodiversity hotspot in Mexico. Zootaxa, 3999 (1), 95–110. https://doi.org/10.11646/zootaxa.3999.1.6
- Rodríguez, G. (2002) El naturalista Antoine Rouhaire (Hermano Nicéforo María) y el desarrollo de la zoología sistemática en Colombia. Revista de la Academia Colombiana de Ciencias Exactas, Físicas y Naturales, 26, 229–238. https://doi.org/10.18257/raccefyn.26(99).2002.2724
- Schmidt, G. (1971) Mit Bananen eingeschleppte Spinnen. Zoologische Beiträge, Neue Folge, 17, 387–433.
- Sherwood, D. & Arzuza Buelvas, D. (2025) A new species of Trachelas L. Koch, 1872 in the bispinosus-group from Colombia (Araneae: Trachelidae). Revista Ibérica de Aracnología, 47, 87–89.
- Simon, E. (1897) Histoire naturelle des araignées. Tome Second. Deuxième Édition. Roret, Paris, 192 pp. https://doi.org/10.5962/bhl.title.51973
- Simon, E. (1898) On the spiders of the island of St Vincent. III. Proceedings of the Zoological Society of London, 65 (4), 860–890. [1897] https://doi.org/10.1111/j.1096-3642.1898.tb01390.x
- Taczanowski, L. (1874) Les aranéides de la Guyane française. Horae Societatis Entomologicae Rossicae, 10, 56–115, pl. 2.
- Wheeler, W.C., Coddington, J.A., Crowley, L.M., Dimitrov, D., Goloboff, P.A., Griswold, C.E., Hormiga, G., Prendini, L., Ramírez, M.J., Sierwald, P., Almeida-Silva, L.M., Álvarez-Padilla, F., Arnedo, M.A., Benavides, L.R., Benjamin, S.P., Bond, J.E., Grismado, C.J., Hasan, E., Hedin, M., Izquierdo, M.A., Labarque, F.M., Ledford, J, Lopardo, L., Maddison, W.P., Miller, J.A., Piacentini, L.N., Platnick, N.I., Polotow, D., Silva-Dávila, D., Scharff, N., Szűts, T., Ubick, D., Vink, C., Wood, H.M. & Zhang, J. (2017) The spider tree of life: phylogeny of Araneae based on target-gene analyses from an extensive taxon sampling. Cladistics, 33, 576–616. https://doi.org/10.1111/cla.12182
- World Spider Catalog (2025) World Spider Catalog. Version 26. Natural History Museum Bern, Bern. Available from: http://wsc.nmbe.ch (accessed 30 December 2025) https://doi.org/10.24436/2
