Phylogenetic analysis of the genus Mischonyx Bertkau, 1880, with taxonomic changes and new species descriptions (Opiliones: Gonylepitdae: Gonyleptinae)

• Ano de defesa: 2020
• Autor(a) principal: Silva, Caio Gueratto Coelho da
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: eng
• Instituição de defesa: Biblioteca Digitais de Teses e Dissertações da USP
• Palavras-chave em Português: Análise Filogenética; Mischonyx; Opiliones; Phylogenetic analysis
• Link de acesso: http://www.teses.usp.br/teses/disponiveis/41/41133/tde-15062020-144613/

Bertkau described Mischonyx genus based on a juvenile, in 1880. This holotype is lost, and we can analyze now only the original drawing and the description. Kury, in 2003, considered other genus junior synonyms of Mischonyx (e.g. Ilhaia and Xundarava). Due to revision publications, the genus contained 11 species. However, until this moment, none proposed a phylogenetic hypothesis for the genus to analyze whether it is valid or not and if all described species as Mischonyx represent a natural clade. The objectives of this research are: to propose a phylogenetic hypothesis for Mischonyx based on Total Evidence (TE), to propose taxonomic changes based on the phylogeny and analyse the phylogenetic hypothesis biogeographically as well. I studied 54 individuals, 15 of external group and 39 of internal group. I sequenced seven genes (28S, 12S, 16S, COI, CAD, ITS e H3), totalizing 3742 bp. I raised 124 morphological and genitalic characters. I analysed the dataset under two optimality criteria: Maximum likelihood (ML) and Maximum parsimony (MP). The hypothesis with better biogeographic and morphological background is the TE with ML. I described Three new species: Mischonyx minimus sp. nov. (type locality: Petrópolis, Rio de Janeiro), Mischonyx intervalensis sp. nov. (type locality: Ribeirão Grande, São Paulo) and Mischonyx petroleiros sp. nov (type locality: Nova Iguaçu, Rio de Janeiro). The genus Urodiabunus is junior synonym of Mischonyx. Geraercormobius bresslaui Roewer, 1927, Geraecormobius clavifemur Mello-Leitão, 1927 and Geraecormobius reitzi Vasconcelos, 2005 were transferred to Mischonyx. M. cuspidatus Roewer, 1913 is junior synonym of M. squalidus Bertkau, 1880. By the phylogenetic hypothesis of relationship, Gonyleptes antiquus Mello-Leitão, 1934 (former Mischonyx antiquus) cannot be considered a Mischonyx species, therefore I reestablish the original composition. The new composition for Mischonyx comprises 17 species, with 7 new combinations. I discuss the transformation of character states throughout the phylogeny, the different phylogenetic hypothesis using different datasets and the congruence of evidence between the clades in the phylogenetic hypothesis with the biogeographical hypothesis on Atlantic Forest areas of endemism