Mystery on the Bounty: The family-level status of Pacificana cockayni Hogg, 1904 (Araneae).

The family-level placement of the species Pacificana cockayniHogg, 1904 (Araneae, Miturgidae) has been ambiguous for over a century, with the monotypic genus Pacificana initially placed in Agelenidae, later transferred to Amaurobioidinae (Anyphaenidae), and presently in Miturgidae. A recent work describing the male and molecular data consisting of a single mitochondrial gene, cytochrome c oxidase subunit I, confirmed that the species is part of the marronoid clade; however, these data did not result in a conclusive family-level placement. Here, we use low-coverage whole genome sequencing (lcWGS) combined with data from the Sequence Read Archive to infer a phylogeny from ultraconserved elements (UCEs) and six legacy Sanger loci.

Terrestrial locomotion in arachnids.

In this review, we assess the current state of knowledge on terrestrial locomotion in Arachnida. Arachnids represent a single diverse (>100,000 species) clade containing well-defined subgroups (at both the order and subordinal levels) that vary morphologically around a basic body plan, yet exhibit highly disparate limb usage, running performance, and tarsal attachment mechanisms. Spiders (Araneae), scorpions (Scorpiones), and harvestmen (Opiliones) have received the most attention in the literature, while some orders have never been subject to rigorous mechanical characterization.

Inclusive fitness theory and eusociality.

Arising from M. A. Nowak, C.

Evidence of behavioral co-option from context-dependent variation in mandible use in trap-jaw ants (Odontomachus spp.).

Evolutionary co-option of existing structures for new functions is a powerful yet understudied mechanism for generating novelty. Trap-jaw ants of the predatory genus Odontomachus are capable of some of the fastest self-propelled appendage movements ever recorded; their devastating strikes are not only used to disable and capture prey, but produce enough force to launch the ants into the air. We tested four Odontomachus species in a variety of behavioral contexts to examine if their mandibles have been co-opted for an escape mechanism through ballistic propulsion.

Phylogeny, scaling, and the generation of extreme forces in trap-jaw ants.

Trap-jaw ants of the genus Odontomachus produce remarkably fast predatory strikes. The closing mandibles of Odontomachus bauri, for example, can reach speeds of over 60 m s(-1). They use these jaw strikes for both prey capture and locomotion - by striking hard surfaces, they can launch themselves into the air.

The evolution of genome size in ants.

Background: Despite the economic and ecological importance of ants, genomic tools for this family (Formicidae) remain woefully scarce. Knowledge of genome size, for example, is a useful and necessary prerequisite for the development of many genomic resources, yet it has been reported for only one ant species (Solenopsis invicta), and the two published estimates for this species differ by 146.7 Mb (0.

More data, fewer shifts: molecular insights into the evolution of the spinning apparatus in non-orb-weaving spiders.

All spiders produce silk and use it for various functions throughout their lives, but not all spiders produce the same silks, or use them for the same functions. These functions may include building shelters, protecting eggs, and trapping prey. The "RTA clade" of spiders (grass spiders, jumping-spiders, wolf spiders, hackled-band weavers, etc.