Abstract
The harvestmen family Gonyleptidae (Opiliones), the largest one in the Neotropics (Kury 2003), is astonishingly diverse in eastern South America. The species-rich genus Eusarcus Perty, 1833, is characteristic for this area. It is the second largest gonyleptid genus (Kury 2003; Hara & Pinto-da-Rocha 2010), with a long taxonomical history beginning in the 19th century, when Perty (1833) described the genus together with four species. The number of species increased gradually in the 20th century through the addition of new descriptions and the synonymies of several related genera, with the corresponding species transferals (Hara & Pinto-da-Rocha 2010). Eusarcus is a relatively well-studied taxon that has undergone a thorough systematic revision (Hara & Pinto-da-Rocha 2010). Currently the genus contains 40 valid species, some of them cave-dwellers, with 32 species inhabiting the Atlantic rainforest and Paraná semi-deciduous forests (Saraiva & DaSilva 2016; Santos Júnior et al. 2021). The remaining species are peripheral to the core geographic area and are found in the Brazilian Cerrado, in Paraguay, or in the “Pampas” grasslands of Argentina, Uruguay, and southern Brazil (Hara & Pinto-da-Rocha 2010).
References
Acosta, L.E. (1993) El género Pachyloidellus Müller, 1918 (Opiliones, Gonyleptidae, Pachylinae). Bonner zoologische Beiträge, 44 (1–2), 1–18.
Acosta, L.E. (2002) Patrones zoogeográficos de los opiliones argentinos (Arachnida: Opiliones). Revista Ibérica de Aracnología, 6, 69–84.
Canestrini, G. (1888) Intorno ad alcuni Acari ed Opilionidi dell’ America. Atti della Società Veneto-Trentina di Scienze Naturali, Padova, Series 1, 11 (1), 100–111.
Guariento, L.A., Bonvicini, M.C., Ballarin, L., Devincenzo, U., Gardini, G., Moretto, E., Pantini, P. & Nicolosi, P. (2018) Giovanni Canestrini’s heritage at the Zoology Museum of Padova University (Italy): a rediscovery of his arachnological collections and described species. Arachnologische Mitteilungen/Arachnology Letters, 55 (1), 36–41. https://doi.org/10.30963/aramit5506
Hara, M.R. & Pinto-da-Rocha, R. (2010) Systematic review and cladistic analysis of the genus Eusarcus Perty 1833 (Arachnida, Opiliones, Gonyleptidae). Zootaxa, 2698 (1), 1–136. https://doi.org/10.11646/zootaxa.2698.1.1
Koch, C.L. (1839) Die Arachniden getreu nach der Natur abgebildet und beschrieben. Siebenter Band. C. H. Zeh’schen Buchhandlung, Nürnberg, 106 pp., pls. 217–247.
Kury, A.B. (2003) Annotated catalogue of the Laniatores of the New World (Arachnida, Opiliones). Revista Ibérica de Aracnología, Volumen especial monográfico, 1, 5–337.
Mello-Leitão, C.F. de (1930) Nota sobre arachnideos argentinos. I. Ainda o genero Apembolephaenus. II. Um genero e tres especies novas de Gonyleptidas. Annaes da Academia Brasileira de Sciencias, 2 (4), 211–214.
Mello-Leitão, C.F. de (1931) Notas sobre arachnídeos argentinos. Annaes da Academia Brasileira de Ciencias, 3 (2), 83–97.
Müller, A. (1918) Einige neue Gonyleptidae. Zoologischer Anzeiger, 49 (3–4), 89–94.
Perty, M. (1833) Delectus animalium articulatorum. Martius, C.F. ed., Monachus [Munich], III + 224 + 40 pp.
Ringuelet, R.A. (1955) Noticias sobre opiliones del Uruguay. Notas del Museo de La Plata, Zoología, 18 (163), 279–297.
Ringuelet, R.A. (1959) Los arácnidos argentinos del orden Opiliones. Revista del Museo Argentino de Ciencias Naturales Bernardino Rivadavia, Ciencias Zoológicas, 5 (2), 127–439, pls. I–XX.
Roewer, C.F. (1913) Die Familie der Gonyleptiden der Opiliones-Laniatores. Archiv für Naturgeschichte, 79A (4), 1–256.
Santos Júnior, G.A. dos, Ázara, L.N. de & Ferreira, R.L. (2021) Three new species of Eusarcus Perty, 1833 (Opiliones, Gonyleptidae) from Brazilian caves. European Journal of Taxonomy, 740 (1), 36–54. https://doi.org/10.5852/ejt.2021.740.1279
Saraiva, N.E.V. & DaSilva, M.B. (2016) Event-based biogeography of Eusarcus dandara sp. nov. (Opiliones: Gonyleptidae), an endemic species of the Northern Atlantic Rainforest of Brazil, and its closely related species. Zootaxa, 4205 (6), 532–548. https://doi.org/10.11646/zootaxa.4205.6.2
Soares, B.A.M. & Soares, H.E.M. (1945) Mais opiliões pertencentes ao Museu Paranaense. Revista de Agricultura, Piracicaba, 20 (9–12), 365–377.
Soares, H.E.M. (1966) Opiliões da coleção Gofferjé (Opiliones: Gonyleptidae, Phalangodidae). Papéis Avulsos do Departamento de Zoologia, São Paulo, 18 (10), 87–102.
Soares, H.E.M. & Soares, B.A.M. (1985) Contribution à l’étude des opilions (Opiliones: Cosmetidae, Phalangodidae, Gonyleptidae) du Paraguay. Revue Suisse de Zoologie, 92 (1), 3–18. https://doi.org/10.5962/bhl.part.81597
Sørensen, W. (1884) Opiliones Laniatores (Gonyleptides W. S. Olim) Musei Hauniensis. Naturhistorisk Tidsskrift, Series 3, 14 (3), 555–646.
Sørensen, W. (1895) Viaggio del dottor Alfredo Borelli nella Repubblica Argentina e nel Paraguay. XVII. Opiliones Laniatores. Bollettino dei Musei di Zoologia ed Anatomia Comparata della R. Università di Torino, 10 (210), 1–6.
Thorell, T. (1877) Sobre algunos arácnidos de la República Argentina. Periódico Zoológico, 2 (4), 201–218