Species delimitation, biogeography, and natural history of dwarf funnel web spiders (Mygalomorphae, Hexurellidae, ) from the United States / Mexico borderlands.

The rarely encountered spider genus Gertsch & Platnick, 1979 includes some of the smallest mygalomorph spiders in the world, with four poorly known taxa from central and southeastern montane Arizona, southern California, and northern Baja California Norte. At time of description the genus was known from fewer than 20 individuals, with sparse natural history information suggesting a vagrant, web-building, litter-dwelling natural history. Here the first published taxonomic and natural history information for this taxon is provided in more than 50 years, working from extensive new geographic sampling, consideration of male and female morphology, and sequence capture-based nuclear phylogenomics and mitogenomics.

New species in old mountains: integrative taxonomy reveals ten new species and extensive short-range endemism in spiders (Araneae, Nesticidae) from the southern Appalachian Mountains.

This revision is based on sampling efforts over the past three decades in the southern Appalachian Mountains which have provided (Araneae, Nesticidae) collections of approximately 2100 adult specimens from more than 475 unique collecting events. Using a "morphology first" framework we examined recently collected specimens plus museum material to formulate morphology-based species hypotheses for putative new taxa (discovery phase). Using sequence capture of nuclear ultraconserved elements (UCEs) we analyzed 801 nuclear loci to validate new (and prior) morphology-based species hypotheses (validation phase) and reconstructed a robust backbone phylogeny including all described and new species.

 (Boraginaceae), a new species endemic to the dry Puna of Chile.

In an earlier molecular phylogenetic study, a sample of what was originally identified as (Boraginaceae) from Chile, grouped with species of the genus . This sample was subsequently shown not to be , but an undescribed species, endemic to the dry Puna of Chile. This new species is described here as , along with a key to all South American species of the genus.

Phylogenomics of paleoendemic lampshade spiders (Araneae, Hypochilidae, ), with the description of a new species from montane California.

is a relictual lineage of Nearctic spiders distributed disjunctly across the United States in three montane regions (California, southern Rocky Mountains, southern Appalachia). Phylogenetic resolution of species relationships in has been challenging, and conserved morphology coupled with extreme genetic divergence has led to uncertain species limits in some complexes. Here, interspecies relationships have been reconstructed and cryptic speciation more critically evaluated using a combination of ultraconserved elements, mitochondrial CO1 by-catch, and morphology.

Nomenclatural revision of (Boraginaceae s. str.) names linked to South American taxa.

During the preparation of the treatment of the genus Lehmann ex G. Don for South America, numerous names were identified as needing typification to stabilize their nomenclature. As a result, lectotypes are designated for 11 names and second-step lectotypes for 20 names.

Sitticine jumping spiders: phylogeny, classification, and chromosomes (Araneae, Salticidae, Sitticini).

The systematics of sitticine jumping spiders is reviewed, with a focus on the Palearctic and Nearctic regions, in order to revise their generic classification, clarify the species of one region (Canada), and study their chromosomes. A genome-wide molecular phylogeny of 23 sitticine species, using more than 700 loci from the arachnid Ultra-Conserved Element (UCE) probeset, confirms the Neotropical origins of sitticines, whose basal divergence separates the Aillutticina (a group of five Neotropical genera) from the subtribe Sitticina (five genera of Eurasia and the Americas). The phylogeny shows that most Eurasian sitticines form a relatively recent and rapid radiation, which we unite into the genus Simon, 1868, consisting of the subgenera Simon, 1901 (seven described species), (41 described species), and Prószyński, 2017 (one species).