First global molecular phylogeny and biogeographical analysis of two arachnid orders (Schizomida and Uropygi) supports a tropical Pangean origin and mid‐Cretaceous diversification

Abstract

Aim: We sought to illuminate the history of the arachnid orders Schizomida and Uropygi, neither of which have previously been subjected to global molecular phylogenetic and biogeographical analyses.Location: Specimens used in this study were collected in all major tropical and subtropical areas where they are presently found, including the Americas, Africa, Australia and the Indo-Pacific region.Methods: From field-collected specimens, we sequenced two nuclear and two mitochondrial markers, combined these with publicly available data, and conducted multi-gene phylogenetic analyses on 240 Schizomida, 24 Uropygi and 12 other arachnid outgroups. Schizomid specimens included one specimen from the small family Protoschizomidae; other schizomid specimens were in Hubbardiidae, subfamily Hubbardiinae, which holds 289 of the order's 305 named species. We inferred ancestral areas using the Dispersal-Extinction-Cladogenesis model of range evolution, and we used fossil calibrations to estimate divergence times. Results:We recovered monophyletic Schizomida and Uropygi as each other's sister group, forming the clade Thelyphonida, and terminals from the New World were usually positioned as the earliest diverging lineages. The ancestral area for

A Critical Appraisal of the Placement of Xiphosura (Chelicerata) with Account of Known Sources of Phylogenetic Error

“…The taxon sampling comprised 53 terminals, with Chelicerata represented by three Xiphosura, two Pycnogonida, and 34 arachnids. Exemplars of all extant arachnid orders were included except Schizomida (sister group to Uropygi ; Clouse et al, 2017) and Palpigradi (incertae sedis; Shultz 2007;Sharma et al 2014a). Outgroup taxa consisted of eight Pancrustacea, five Myriapoda, and one Onychophora.…”

Taxon cycle predictions supported by model‐based inference in Indo‐Pacific trap‐jaw ants (Hymenoptera: Formicidae: Odontomachus)

“…This pattern suggests a more important role of eastern Melanesia, namely Fiji and the Solomon Islands, in macroevolutionary dispersal of Stage I taxa in the Indo‐Pacific. These areas might have acted as a hub area for New World taxa entering the Indo‐Pacific region; a hypothesis that has been put forward in ants (Clouse et al., ) and other arthropod groups (Clouse et al., ; Sharma & Giribet, ). However, our interpretation does not challenge the importance of SE Asia as a source region for Indo‐Pacific taxa.…”

Taxonomy of the thelyphonid genus Typopeltis Pocock, 1894, including homology proposals for the male gonopod structures (Arachnida, Thelyphonida, Typopeltinae)

“…The order Thelyphonida Latreille, 1804 (also known as whip scorpions) is a conspicuous, yet small arachnid order with only 124 living species in 15 genera described so far (Zhang 2013, Barrales-Alcalá et al 2018). Despite not being extremely diverse, the group is quite old and is estimated to have originated around 333 mya in tropical Pangea (Clouse et al 2017). The oldest Thelyphonida fossil is from 318 mya and currently only seven fossils are known (Dunlop et al 2008, Wolfe et al 2016).…”

“…The oldest Thelyphonida fossil is from 318 mya and currently only seven fossils are known (Dunlop et al 2008, Wolfe et al 2016). Recent estimates of time divergence indicate an increase in diversification rates during the Cretaceous (Clouse et al 2017).…”

“…Not much is known regarding the phylogenetic relationships of Typopeltis species. In a molecular phylogeny of Thelyphonida, Clouse et al (2017) included only one named species of Typopeltis , T.crucifer , which was recovered as sister to what was most likely an unnamed species in the same genus from Vietnam. Interestingly, Typopeltinae was recovered as being more closely related to Thelyphoninae and Mastigoproctinae than to Hypoctoninae.…”