Genitalic morphology and phylogenomic placement of the Australian spider Paraplectanoides crassipes Keyserling, 1886 (Araneae, Araneidae) with a discussion on the classification of the family Araneidae

Abstract

We complement and expand the existing descriptions of the Australian araneid spider Paraplectanoides crassipes Keyserling, 1886, and provide the first detailed analysis of the male palpal homologies to include examination of the expanded organ and scanning electron micrographs of the palpal sclerites. We study the placement of Paraplectanoides and the classification of the family Araneidae by combining ultraconserved elements with Sanger markers. We also added Sanger sequences of the Australian araneid genus Venomius to the molecular dataset of Scharff et al. (2020) to explore the phylogenetic placement and implications for classification of the family. We evaluate a recent proposal on the classification of the family Araneidae by Kuntner et al. (2023) in which a new family is erected for P. crassipes. Paraplectanoides is monotypic. Examination of the type material shows that Paraplectanoides kochi O. Pickard-Cambridge, 1877 is misplaced in the genus and the name is a senior synonym of the araneid Isoxya penizoides Simon, 1887 (new synonymy) that results in the new combination Isoxya kochi (O. Pickard-Cambridge, 1877). The classification of Araneidae is revised and the following nomenclatural acts are introduced: Paraplectanoididae Kuntner, Coddington, Agnarsson and Bond, 2023 is a junior synonym of Araneidae Clerck, 1757 new synonymy; phonognathines and nephilines are subfamilies of Araneidae (Subfamily Phonognathinae Simon, 1894 rank resurrected; and Subfamily Nephilinae Simon, 1894 rank resurrected). The results of our analyses corroborate the sister group relationship between Paraplectanoides and the araneid subfamily Nephilinae. Venomius is sister to the Nephilinae + Paraplectanoides clade. The placement of the oarcine araneids and Venomius renders the family Araneidae non-monophyletic if this were to be circumscribed as in Kuntner et al. (2023). In light of the paucity of data that the latter study presents, and in absence of a robust, stable and more densely sampled phylogenetic analysis of Araneidae, the changes and definitions introduced by that classification are premature and could lead to a large number of new families for what once were araneid species if the maximum-crown-clade family definitions were to be used. Consequently, we argue for restoring the familial and subfamilial classification of Araneidae of Dimitrov et al. (2017), Scharff et al. (2020) and Kallal et al. (2020).