Giant Goblins above the waves at the southern end of the world: The biogeography of the spider family Orsolobidae (Araneae, Dysderoidea)

Aim As a continental island, much of the biota of New Zealand was initially thought to have been shaped by vicariance. Recent studies, however, have highlighted the role of dispersal, with some even suggesting that the entire biota is the product of dispersal events following emergence of the islands. This study focuses on the interplay between dispersal and vicariance, specifically asking whether the spider family Orsolobidae has Gondwanan origins on New Zealand. Location The spider family Orsolobidae was sampled from all continents where they occur (Africa, Australia, New Zealand and South America), comprising a total of 66 specimens representing the phylogenetic diversity of the family. Methods DNA sequences were obtained from six fragments that were subsequently aligned and analysed with MrBayes3.2 and beast 1.8. The phylogeny was calibrated with fossils used as node calibrations, as well as with the substitution rate of Histone H3. Results The orsolobid fauna of each land mass except Australia forms a monophyletic group in our analyses. The divergence dating analysis suggests that diversification of Orsolobidae started at a minimum of 80 Ma, while the New Zealand clade dates from a minimum of 40 Ma. Main conclusions Thus, while many taxa have colonized the islands by dispersal, certain lineages, including the Orsolobidae, have clearly been capable of persisting through times of reduced land area.