A taxonomic review of the crab spider genus Sidymella (Araneae, Thomisidae) in the Neotropics

Abstract

Four Neotropical species of Sidymella Strand, 1942, S.furcillata Keyserling, 1880, S.longispina (Mello-Leitão, 1943), S.lucida (Keyserling, 1880), and S.kolpogaster (Lise, 1973) are redescribed from both sexes. The holotype of S.nigripes (Mello-Leitão, 1947) is lost and this taxon is considered a species inquierenda. Sidymellaobscura (Mello-Leitão, 1929), S.parallela (Mello-Leitão, 1929), and S.spinifera (Mello-Leitão, 1929) are all nomina dubia. Two new species are described: Sidymellaexcavatasp. nov. (males and females) and S.marmoratasp. nov. (female).

Phylogenetic relationships in Stephanopinae: systematics of Stephanopis and Sidymella based on morphological characters (Araneae: Thomisidae)

“…The genus that gives name to the subfamily had its Australian species recently revised by Machado et al (2019b), but despite the recent efforts to better understand the morphology of Stephanopis O. Pickard-Cambridge, 1869, our knowledge regarding the Neotropical and Andean species of the genus relies only on original descriptions. A similar scenario is observed for Sidymella Strand, 1942, which also had its diagnosis and description updated by Machado et al (2019a). However, in this case, only the Neotropical species were considered in the taxonomic work while the Australian ones remain in need of revision.…”

“…The subfamily Stephanopinae has been the focus of recent revisional works (Benjamin 2013(Benjamin , 2015(Benjamin , 2016(Benjamin , 2017Machado et al 2015Machado et al , 2017Machado et al , 2018Machado et al , 2019aSilva-Moreira and Machado 2016;Prado et al 2018). Even so, most of its component genera are still poorly known and diagnosed, which is reflected in the lack of resolution and constant recovery of its polyphyletic relations (Benjamin et al 2008;Benjamin 2011;Wheeler et al 2017).…”

“…Stephanopis is indeed monophyletic. The same question deserves a proper study in regard to the bifid opisthosoma of Sidymella species, a trait that was still recently considered by Machado et al (2019a) as one of the main traits to diagnose the genus.…”

Kryptochroma: a new genus of bark-dwelling crab spiders (Araneae, Thomisidae)

“…The morphological aspects and taxonomic boundaries of Neotropical stephanopines have been extensively studied during the past years (Machado et al 2015(Machado et al , 2018(Machado et al , 2019aSilva-Moreira & Machado 2016). Meanwhile, phylogenies based on morphological and molecular data were congruent in recovering some close related genera, corroborating classic propositions for the possible existence of tribes or even certain "groups" in this subfamily (Benjamin 2011;Benjamin et al 2008;Wheeler et al 2017;Machado et al 2017Machado et al , 2019bMachado & Teixeira 2021).…”

Diversidad taxonómica de Thomisidae (Araneae) en ambientes heterogéneos del sitio Ramsar Humedales Chaco, Argentina

“…Existen diversos trabajos orientados a redescribir y escribir diferentes especies de tomísidos y a resolver las relaciones filogenéticas intragrupo. Al respecto se puede citar a Benjamin et al (2008); Benjamin (2011Benjamin ( , 2013Benjamin ( , 2015Benjamin ( , 2017; Sirvid et al (2013); Silva-Moreira y Machado (2016); Machado et al (2019aMachado et al ( , 2019bMachado et al ( , 2019c; Grismado y Achitte-Schmutzler (2020) y Machado y Texeira (2021) entre otros. Los conocimientos acerca de su ecología, taxonomía y diversidad aún son incipientes en Argentina, actualmente se conocen 60 especies (CAA c2018) mientras que a nivel mundial se registran 2160 especies de Thomisidae (WSC c2018).…”