20.500.12556/DiRROS-23750 Taxonomy, phylogeny, and size evolution in the spider genus Megaraneus Lawrence, 1968 (Araneae: Araneidae) Among terrestrial animals, spiders exhibit the most striking examples of sexual size dimorphism (SSD) but better understanding of its evolution requires improved taxonomy and phylogeny. Many sexually dimorphic spiders lack adequate description, phylogenetic placement, and natural history observations. In South Africa, we documented the natural history of a poorly known spider, Megaraneus gabonensis (Lucas, 1858), with extreme, female-biased SSD (eSSD, female:male approximately 4:1). Here, we redescribe M. gabonensis, place Megaraneus Lawrence, 1968 phylogenetically for the first time, assess whether the observed eSSD represents an independent evolutionary origin, and test whether the macroevolutionary pattern is better explained by male dwarfism or female gigantism. The recovered phylogenetic placement of Megaraneus in the araneid ‘backobourkiines’, a clade previously considered as restricted to East Asia and Australasia, extends the range of this clade to the Afrotropics. We find that eSSD was present in the common ancestor of the ‘backobourkiines’, with further increases in female body length occurring independently in Megaraneus, Backobourkia Framenau, Dupérré, Blackledge & Vink, 2010, and the currently misplaced Parawixia dehaani (Doleschall, 1859). We conclude that the evolution of eSSD reflects a complex pattern of sex-specific size changes across spider phylogeny, but that in Megaraneus it results from female gigantism. sexual size dimorphism backobourkiines trait evolution South Africa velikostni spolni dimorfizem evolucija lastnosti Južna Afrika pajki true false true Angleški jezik Slovenski jezik Neznano 2025-09-30 12:22:10 2025-09-30 12:22:11 2025-10-24 03:54:58 0000-00-00 00:00:00 2025 0 0 Nasl. z nasl. zaslona; Soavtorji: Eva Turk, Pedro de Souza Castanheira, Kuang-Ping Yu, Matjaž Gregorič, Volker W. Framenau, Ingi Agnarsson, Matjaž Kuntner; Opis vira z dne 24. 9. 2025; Str. 1-17 issue 10, [article no.] 992 Vol. 16 2025 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 2025-09-24 595.44 2075-4450 10.3390/insects16100992 250274307 https://www.mdpi.com/2075-4450/16/10/992 1 7130315b-9de7-11f0-9bb7-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=35204 RAZ_Candek_Klemen_2025.pdf RAZ_Candek_Klemen_2025.pdf 1 3E6298B0C3BB60CBDE9778C6E8761563 868a8af95b1fa10f89d34ecb7a71f45646ebd57f4836fc06cb0b365abeb086a0 d3cafdc2-9de7-11f0-9bb7-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=35205 Nacionalni inštitut za biologijo 0 0 0