A new small Acanthogonatus Karsch, 1880 (Mygalomorphae, Pycnothelidae) species from Argentinean Patagonia: description of A. messii Signorotto & Ferretti n. sp. and its phylogenetic placement Author Signorotto, Fiorella Author Mancini, Mariana Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur, San Juan 670, Bahía Blanca (8000), Buenos Aires (Argentina) Author Ferretti, Nelson Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur, San Juan 670, Bahía Blanca (8000), Buenos Aires (Argentina) and Centro de Recursos Naturales Renovables de la Zona Semiárida (CERZOS-UNS, CONICET), Camino La Carrindanga Km. 7, Bahía Blanca (8000), Buenos Aires (Argentina) nferretti @ conicet. gov. ar (corresponding author) text Zoosystema 2023 2023-09-26 45 17 499 512 https://sciencepress.mnhn.fr/sites/default/files/articles/pdf/zoosystema2023v45a17_0.pdf journal article 270321 10.5252/zoosystema2023v45a17 dd6aa488-f2ce-4641-9392-5c428430fc96 1638-9387 8382549 C92EEB3F-2639-4891-958E-B8CE87EB74F1 Genus Acanthogonatus Karsch, 1880 Acanthogonatus Karsch, 1880: 391 . — Raven 1985: 83 (transferred from the Barychelidae Simon, 1889 to the Nemesiidae ). — Opatova et al. 2020: 701 (transferred to the Pycnothelidae ). Tryssothele Simon, 1902: 7 . TYPE SPECIES . — By original designation, Acanthogonatus francki Karsch, 1880 . DIAGNOSIS . — See Goloboff (1995) : 73.