A well‐resolved transcriptomic phylogeny of the mite harvestman family Pettalidae (Arachnida, Opiliones, Cyphophthalmi) reveals signatures of Gondwanan vicariance

• Published in: Journal of Biogeography
• Main Authors: Baker, Caitlin M., Boyer, Sarah L., Giribet, Gonzalo
• Other Authors: National Science Foundation
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2020
• Subjects: Antarctic; New Zealand; Queensland; Antarc*; Antarctica; Mite
• Online Access: http://dx.doi.org/10.1111/jbi.13828; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fjbi.13828; https://onlinelibrary.wiley.com/doi/pdf/10.1111/jbi.13828; https://onlinelibrary.wiley.com/doi/full-xml/10.1111/jbi.13828; https://onlinelibrary.wiley.com/doi/am-pdf/10.1111/jbi.13828

Abstract Aim We explored the extent to which Gondwanan vicariance contributed to the circum‐Antarctic distribution of the mite harvestman family Pettalidae, a group of small, dispersal‐limited arachnids whose phylogeny has been poorly resolved, precluding rigorous biogeographic hypothesis testing. Location Continental landmasses of former temperate Gondwana (Chile, South Africa, Sri Lanka, Australia and New Zealand). Taxon Pettalidae, Opiliones. Methods We generated transcriptomes for a phylogeny of 16 pettalids, spanning 9 genera. Data were analysed using maximum likelihood, Bayesian inference and coalescence methods. The phylogenetic position of the Sri Lankan genus Pettalus was further explored using quartet likelihood mapping and changes in gene likelihood scores. We also estimated divergence times and looked for signatures of extinction across Antarctica and central Australia using previously published phylogenies with near‐complete species sampling constrained to match our transcriptomic results. Finally, we estimated ancestral ranges and inferred instances of vicariance. Results We recovered a well‐supported topology with a division between taxa from landmasses that made up East Gondwana, and a grade of taxa from West Gondwana. Pettalus was resolved either as the sister group of the Queensland‐endemic Austropurcellia , or as the sister group to a larger clade from East Gondwana, though favouring Pettalus + Austropurcellia . Divergence times for multiple vicariance events coincided with Gondwana's breakup. Speciation–extinction analysis found one diversification process for the family: an initial burst of cladogenesis that slowed down through time. Main Conclusions Given that the order of cladogenesis corresponds to the order in which Gondwana fragmented, and the concurrent timing of vicariance and rifting, Gondwanan breakup explains major biogeographic patterns in Pettalidae. Some divergences predate initial rifting, but there is no evidence of trans ‐oceanic dispersal. The Sri Lanka–eastern Australia ...