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Abstract This study summarizes the taxonomic treatment of the camel spider genus Chanbria Muma, 1951. Taking an integrative taxonomic approach incorporating phylogenomic, morphological, and geographical information, the genus is herein revised. Of the four species currently placed in the genus, two are retained: Chanbria regalis Muma, 1951 and Chanbria serpentinus Muma, 1951. Eremochelis plicatus (Muma, 1962) is transferred to this genus because it is consistently recovered in a clade with Chanbria based on several phylogenetic analyses using hundreds of loci recovered from ultraconserved element data. In this study, we re-analyse previously acquired genomic data to assess former species hypotheses and identify new morphological synapomorphies that support the monophyly of Chanbria. The genetic data support the synonymization of Chanbria rectus Muma, 1962 syn. nov. with C. regalis. Furthermore, we synonymize Chanbria tehachapianus Muma, 1962 syn. nov. with C. regalis because C. tehachapianus was erected based on limited morphological information and lack of geographical separation between other populations of C. regalis. Two new species, Chanbria brookharti sp. nov. and Chanbria mapemes sp. nov., are described. This brings the total number of species of Chanbria described to five recognized species: C. regalis, C. serpentinus, C. plicatus com. nov., C. brookharti sp. nov., and C. mapemes sp. nov. 

Abstract Morphology has long been used to classify and identify living organisms. However, taxonomic descriptions are often limited to qualitative descriptions of size and shape, making identification difficult due to the subjective language used to describe complex shapes. Additionally, for some taxa, there are few reliable qualitative characters available for delimitation that have yet to be tested objectively in a phylogenetic context. Solifugae is one such example. The order, Solifugae, is recognized from the other arachnid orders by the possession of large, powerful jaws or chelicerae. Male cheliceral morphology is the leading diagnostic character system in solifuge systematics and is the basis for much of solifuge current taxonomy. Female chelicerae, on the other hand, are reportedly deeply conserved and much of the species identification is based on female operculum morphology. To elucidate patterns of chelicerae and opercula trait evolution within the solifuge family, Eremobatidae, we used a 2-dimenstional morphological analysis using an Elliptical Fourier approach for closed outlines, in addition to an analysis of traditionally used measures in a phylogenetic context. Using ancestral state reconstruction and ultra-conserved elements, we assessed the taxonomic utility of female cheliceral and opercular morphology, and we evaluated which male morphological characters reflect shared, derived ancestry. Investigation into ubiquitously used character sets, in addition to newly proposed characters herein, illustrates the complex evolution of traits with high levels of convergence. Our results provide taxonomic insight into future, higher level taxonomic revisions of Eremobatidae. 

Advanced sequencing technologies have expedited resolution of higher-level arthropod relationships. Yet, dark branches persist, principally among groups occurring in cryptic habitats. Among chelicerates, Solifugae ("camel spiders") is the last order lacking a higher-level phylogeny and have thus been historically characterized as "neglected [arachnid] cousins". Though renowned for aggression, remarkable running speed, and xeric adaptation, inferring solifuge relationships has been hindered by inaccessibility of diagnostic morphological characters, whereas molecular investigations have been limited to one of 12 recognized families. Our phylogenomic dataset via capture of ultraconserved elements sampling all extant families recovered a well-resolved phylogeny, with two distinct groups of New World taxa nested within a broader Paleotropical radiation. Divergence times using fossil calibrations inferred that Solifugae radiated by the Permian, and most families diverged prior to the Paleogene-Cretaceous extinction, likely driven by continental breakup. We establish Boreosolifugae new suborder uniting five Laurasian families, and Australosolifugae new suborder uniting seven Gondwanan families using morphological and biogeographic signal. 

Abstract Species of camel spiders in the family Eremobatidae are an important component of arthropod communities in arid ecosystems throughout North America. Recently, research demonstrated that the evolutionary history and biogeography of the family are poorly understood. Herein we explore the biogeographic history of this group of arachnids using genome-wide single nucleotide polymorphism (SNP) data, morphology, and distribution modelling to study the eremobatid genus Eremocosta , which contains exceptionally large species distributed throughout North American deserts. Relationships among sampled species were resolved with strong support and they appear to have diversified within distinct desert regions along an east-to-west progression beginning in the Chihuahuan Desert. The unexpected phylogenetic position of some samples suggests that the genus may contain additional, morphologically cryptic species. Geometric morphometric analyses reveal a largely conserved cheliceral morphology among Eremocosta spp. Phylogeographic analyses indicate that the distribution of E. titania was substantially reduced during the last glacial maximum and the species only recently colonized much of the Mojave Desert. Results from this study underscore the power of genome-wide data for unlocking the genetic potential of museum specimens, which is especially promising for organisms like camel spiders that are notoriously difficult to collect. 

Little is known about the reproductive behaviour of solifuges, or camel spiders (Arachnida: Solifugae). Behavioural research is limited, due in part to challenges of maintaining specimens in the laboratory where they can be best observed. The present study documents the courtship and mating behaviours of a North American solifuge, Eremobates pallipes (Say, 1823) through staged mating encounters in an arena within a laboratory setting. Trials were filmed and analysed to establish sequence and timing of behaviours. We were able to document consistent and predictable aspects of the mating behaviours in this species. The consistent use by males of the suctorial organs during mating was documented for the first time in Eremobatidae.