Evolution of the male palp morphology of the orb-weaver hunting spider Chorizopes (Araneae:Araneidae) revisited on a new phylogeny of Araneidae, and description of a third species from Madagascar

The genus Chorizopes (Araneae, Araneidae) includes over two dozen species of webless araneids found mainly in the Indomalayan region. They are characterised by a distinctive bulbous carapace and a specialised foraging behaviour: preying on other orb-weavers. Chorizopes casictones, sp. nov. (Araneae, Araneidae) is described based on specimens collected in northern Madagascar. This species represents the third member of Chorizopes known from the island. We conducted a total-evidence analysis based on morphology, behaviour and nucleotide sequence data, including this taxon for the first time. The palpal morphology of the male of Chorizopes is illustrated in detail. We discuss the palpal homologies and the evolution of araneid palpal sclerites based on the newly inferred family phylogenetic tree.