Análise cladística de Pycnothelinae e revisão de Rachias Simon, 1892 (Araneae, Mygalomorphae, Nemesiidae)

Abstract

Nemesiidae Simon, 1889 was elevated to family status from the tribe Nemesiae Simon, 1889, described in Ctenizinae Thorell, 1887, being divided into six subfamilies: Anaminae Simon, 1889, Bemmerinae Simon, 1903, Diplothelopsinae Schiapelli & Gerschmann, 1967, Ixamatinae Raven, 1985, Nemesiinae Simon, 1889 e Pycnothelinae Chamberlin, 1917. The last one, occurring in Argentina, Brazil and Uruguay. Goloboff conducted a review and cladistic analysis of Nemesiidae from South American and considered Anaminae and Pycnothelinae paraphyletic, and demonstrated that Nemesiidae was also paraphyletic. Pycnothelinae currently consists of eight genera and 33 species: Hermachura Mello-Leitão, 1923, Neostothis Vellard, 1924, Prorachias, Mello-Leitão, 1924, Psalistopoides Mello-Leitão, 1934, Pselligmus Simon, 1892, Pycnothele Chamberlin, 1917, Rachias Simon, 1892 and Stenoterommata Holmberg, 1881. This study aims to test the monophyly of Pycnothelinae and their included genera, through cladistic analysis. In the ingroup, we included all representatives of each genus described in Pycnothelinae and few undescribed species. Due to the existence of a prior hypothesis of monophyly for the genera included in Diplothelopsini, only part of the largest genera of this taxa were used. The outgroup were composed of representativies of six subfamilies of Nemesiidae and five other Mygalomorphae families. The data matrix has 103 characters and a total of 95 terminals sampled. The topology resulted from the analysis with implied weighting (K=4), was chosen as the working filogenetic relationship hipothesis. The result obtained for the family Nemesiidae corroborates the previous Goloboff hypothesis, that it not form a monophyletic group and that subfamilies: Ixamatinae, Nemesiinae, Anaminae, Pycnothelinae and Diplothelopsinae are paraphyletic. Pycnothelinae is supported by one unambiguous synapomorphy, metatarsos IV with the provision of prolateral superior spines 1-1-1. In this case, Pycnothelinae can only be considered monophyletic, with the eight pre-existing genera listed above, plus the inclusion of Chaco Tullgren, 1905, Chilelopsis Goloboff, 1995, Diplothelopsis Tullgren, 1905, Lycinus Thorell, 1894 and Flamencopsis Goloboff, 1995 (Diplothelopsinae), Acanthogonatus Karsch, 1880 and Longistylus Indicatti & Lucas, 2005 (Anaminae) and Neotropical species of Hermacha Simon, 1889 (except H. conspersa Mello-Leitão, 1941 which belong to Cyrtaucheniidae), in addition to the following species and genera from other families: Psalistops crassimanus Mello-Leitão, 1923 (Barychelidae), Xenonemesia Goloboff, 1988 (Microstigmatidae) and Lasiodora pantherina (Keyserling, 1891) (Theraphosidae). In the present study, the four non-monotypic genera of Pycnothelinae, Psalistopoides, Pycnothele, Rachias, Stenoterommata, as currently delimited are not monophyletic units. All genera and species of Neotropical “Nemesiidae” now belong to the final delimitation Pycnothelinae. Considering the taxonomic changes to be made from these results, Pycnothelinae is delimited by 13 genera and 96 Neotropical species. In this study also is carried out a review of the genus viii Rachias. The genus Psalistopoides is considered a junior synonym of Rachias for presenting the apical region of the embolus dilated and spoon-shaped (as in Rachias dispar Simon, 1891 and Rachias conspersus (Walckenaer, 1837)), strongly folded and malleable keels, reduced number of endits cuspules in both sexes, labium almost square and female spermathecae formed by a dome, which is projected only a branch to the inner region. The female of R. dispar is described for the first time, since the paralectotype female redescribed by Raven, belongs to a new species of Acanthogonatus. The male of R. conspersus is described for the first time. The species, Pycnothele piracicabensis (Piza, 1938) is transferred from Pycnothele to Rachias, restoring the original combination. Rachias caudatus (Piza, 1939) is transferred to Stenoterommata, due to the presence of many endit cuspules and by not presented folded keels. The following synonymies are proposed: Stenoterommata maculata and Rachias virgatus Vellard, 1924 = R. conspersus; Psalistops nigrofemuratus Mello-Leitão, 1939 (transferred from Barychelidae to Nemesiidae) = Rachias fulvimanus (Mello-Leitão, 1934). The following species were considered valid: R. dispar, Rachias aureus (Mello-Leitão, 1920), R. fulvimanus, Rachias emanueli (Lucas & Indicatti, 2006), Rachias brachythelus (Mello-Leitão, 1937), R. conspersus, Rachias dolichosternus (Mello-Leitão, 1938), Rachias piracicabensis, Rachias timbo Goloboff, 1995. Two species were considered nomina dubia: Rachias odontochilus Mello-Leitão, 1923 and Rachias iricolor (Mello-Leitão, 1923) (transferred from Hermacha). Two new species are proposed, Rachias parnaso sp. nov. from Teresópolis, Rio de Janeiro, and Rachias candianii sp. nov. from São Paulo, São Paulo, both from Brazil. nov. Rachias occurs in southeastern and southern Brazil in the states of Rio de Janeiro, São Paulo, Paraná and Santa Catarina and northeastern Argentina, in the province of Misiones.