The evolutionary and biogeographic history of the armoured harvestmen – Laniatores phylogeny based on ten molecular markers, with the description of two new families of Opiliones (Arachnida)

Abstract

We investigated the internal phylogeny of Laniatores, the most diverse suborder of Opiliones, using sequence data from 10 molecular loci: 12S rRNA, 16S rRNA, 18S rRNA, 28S rRNA, cytochrome c oxidase subunit I (COI), cytochrome b, elongation factor-1α, histones H3 and H4, and U2 snRNA. Exemplars of all previously described families of Laniatores were included, in addition to two families – Petrobunidae, fam. nov. and Tithaeidae, fam. nov. – that we erect herein. Data analyses were based on maximum likelihood and Bayesian approaches on static alignments, and included phylogenetic tree estimation, molecular dating, and biogeographic analysis of ancestral area reconstruction. The results obtained include the monophyly of Laniatores and the infraorder Grassatores – the focus of this study – as well as support for numerous interfamilial relationships. The two new families described cluster with other South-east Asian families (Podoctidae and Epedanidae). Diversification of Laniatores is estimated at ~348 Mya, and origin of most Grassatores superfamilies occurs in a ~25 million year span of time immediately after the end-Permian mass extinction (254 Mya). Ancestral range reconstruction of the clade (Samooidea + Zalmoxoidea) suggests that the ancestral range of Samooidea comprises West Tropical Gondwana (West Africa + Neotropics), whereas that of Zalmoxoidea is exclusively Neotropical. The following additional taxonomic changes are proposed: (1) Remyus is transferred to Phalangodidae, and (2) Escadabiidae and Kimulidae are transferred to Zalmoxoidea.