A molecular phylogeny of bark spiders reveals new species from Africa and Madagascar (Araneae: Araneidae: Caerostris)

Bark spiders (genus Caerostris Thorell 1868) are important models in biomaterial research due to the remarkable biomechanical properties of the silk of C. darwini Kuntner & Agnarsson 2010 and its gigantic web. They also exhibit female gigantism and are promising candidates for coevolutionary research on sexual dimorphism. However, Caerostris spiders are taxonomically understudied and the lack of a phylogeny impedes evolutionary research. Using a combination of one mitochondrial and one nuclear marker, we provide the first species-level phylogeny of Caerostris including half of its species diversity but dense terminal sampling focusing on new lineages. Our phylogenetic and morphological results provide the evidence for six previously undescribed species: C. almae n. Sp., C. bojani n. Sp., C. pero n. Sp. and C. wallacei n. Sp., all from Madagascar, C. linnaeus n. Sp. from Mozambique and C. tinamaze n. Sp. from the Republic of South Africa.