A place for everything, and everything in its place: A new genus for the spiny Australian crab spiders (Araneae: Thomisidae)

Recent phylogenetic analyses have shown consistent evidences that the composition of some Stephanopinae genera, as well as their distribution, were wrongly assigned throughout the 20th century. Inaccurate descriptions and vague diagnoses resulted in groups that are actually formed by multiple genera, which were repeatedly recovered as polyphylies. The present work is part of a long-term morphological study that aims to better understand and delineate the taxonomic boundaries of the Australian stephanopines. Hereinafter, we present a new combination for a group of spiders hitherto considered as part of Sidymella Strand, 1942, officially elevating it to a generic rank and highlighting its diagnostic features. The genus Spinaarachne gen.nov. is proposed not only to comprise the new species S. aculeata sp. nov. and S. pilosa sp. nov. but also to accommodate the transference of S. hirsuta (L. Koch, 1874) comb. nov. Brief notes regarding the plausible reasons of why S. hirsuta comb. nov. was previously attributed to a Neotropical genus are presented, and new distribution records are also provided.