Out of the Neotropics: Late Cretaceous colonization of Australasia by American arthropods

Abstract

The origins of tropical southwest Pacific diversity are traditionally attributed to southeast Asia or Australia. Oceanic and fragment islands are typically colonized by lineages from adjacent continental margins, resulting in attrition of diversity with distance from the mainland. Here, we show that an exceptional tropical family of harvestmen with a trans-Pacific disjunct distribution has its origin in the Neotropics. We found in a multi-locus phylogenetic analysis that the opilionid family Zalmoxidae, which is distributed in tropical forests on both sides of the Pacific, is a monophyletic entity with basal lineages endemic to Amazonia and Mesoamerica. Indo-Pacific Zalmoxidae constitute a nested clade, indicating a single colonization event. Lineages endemic to putative source regions, including Australia and New Guinea, constitute derived groups. Divergence time estimates and probabilistic ancestral area reconstructions support a Neotropical origin of the group, and a Late Cretaceous (ca 82 Ma) colonization of Australasia out of the Fiji Islands and/or Borneo, which are consistent with a transoceanic dispersal event. Our results suggest that the endemic diversity within traditionally defined zoogeographic boundaries might have more complex evolutionary origins than previously envisioned.

Ancient Neotropical origin and recent recolonisation: Phylogeny, biogeography and diversification of the Riodinidae (Lepidoptera: Papilionoidea)

“…587 More than 80 genera of plants are, for example, known to have a 588 disjunct Neotropical-Southeast Asian distribution (e.g. tropical 589 'amphi-Pacific' distribution, (Thorne, 1972)), as do several animals 590 with limited dispersal power, such as legless lizards (Townsend 591 et al, 2011), freshwater crustaceans (van Damme and Sinev, 592 2013) and harvestmen (Sharma and Giribet, 2012). Migration via 593 Beringia has been inferred to be the most probable route giving rise 594 to this disjunction for organisms of various ages (e.g.…”

Tropical Amphi-Pacific disjunctions in the Cladocera (Crustacea: Branchiopoda)

“…Several trans-Pacific (not Amphi-Pacific) disjunctions in animals that include New Zealand and oceanic islands in the Pacific, have received a lot of attention. Sharma and Giribet (2012) studied the colonisation of Pacific islands in a group of trans-Pacific terrestrial arachnids (Zalmoxidae, Opiliones) and discussed a few other animal examples with this type of distribution (e.g. Hackett et al, 2008;Keogh et al, 2008).…”

“…Van Steenis, 1962;Heads, 1999;Morley, 2000Morley, , 2001Davis et al, 2002Davis et al, , 2005Givnish and Renner, 2004;Li et al, 2004Li et al, , 2011. (Sharma and Giribet, 2012). Yet, not only plant lineages have many examples.…”

“…trans-Pacific zipper effect; McCarthy, 2003McCarthy, , 2007Briggs, 2004), ancient transantarctic dispersal (Brundin, 1966;Cracraft, 2001;Sanmartín and Ronquist, 2004), ancient and recent transoceanic long-distance dispersal (e.g. Givnish and Renner, 2004;Keogh et al, 2008;Clayton et al, 2009;Sharma and Giribet, 2012) and general relictualism (Eskov and Golovatch, 1986;Bănărescu, 1990Bănărescu, -1995, like the boreotropics hypothesis (Wolfe, 1975;Tiffney, 1985;Morley, 2000Morley, , 2001. None of the theories can reconcile the current geological and biogeographical data (Sluys, 1994) and some are highly debated (Cox, 1990;Briggs, 2004).…”

World Checklist of Opiliones species (Arachnida). Part 2: Laniatores – Samooidea, Zalmoxoidea and Grassatores incertae sedis

“…On one hand we have evidence for a strong Zalmoxoidea sensu Sharma and Giribet (Sharma and Giribet 2011) (BS = 89%, PP = 1.00) whereas Samooidea it is recovered as monophyletic but with limited support (BS = 53%, PP = 0.62) (Sharma and Giribet 2011). That could be a reflection that whereas the taxon sampling for Zalmoxoidea has been greatly enhanced lately (Sharma and Giribet 2011, Sharma and Giribet 2012) the taxon sampling for Samooidea still remains unsatisfactory. More effort is needed in studying and sequencing African and Indo-Pacific lineages (Sharma and Giribet 2011), as well as enhancing the representation of Neotropical and Australasian terminals in order to test Samooidea as a natural group and improve the hypotheses of relationship inside the Samooidea/Zalmoxoidea clade.…”