Patterns in schizomid flagellum shape from elliptical Fourier analysis.

The arachnid order Schizomida is a relatively understudied group of soil-dwelling predators found on all continents except Antarctica. While efforts to understand their biology are growing, there is still much to know about them. A curious aspect of their morphology is the male flagellum, a sexually dimorphic, tail-like structure which differs in shape across the order and functions in their courtship rituals.

Not So Fast: Strike Kinematics of the Araneoid Trap-Jaw Spider (Malkaridae: Pararchaeinae).

To capture prey otherwise unattainable by muscle function alone, some animal lineages have evolved movements that are driven by stored elastic energy, producing movements of remarkable speed and force. One such example that has evolved multiple times is a trap-jaw mechanism, in which the mouthparts of an animal are loaded with energy as they open to a wide gape and then, when triggered to close, produce a terrific force. Within the spiders (Araneae), this type of attack has thus far solely been documented in the palpimanoid family Mecysmaucheniidae but a similar morphology has also been observed in the distantly related araneoid subfamily Pararchaeinae, leading to speculation of a trap-jaw attack in that lineage as well.

Converging on the orb: denser taxon sampling elucidates spider phylogeny and new analytical methods support repeated evolution of the orb web.

High throughput sequencing and phylogenomic analyses focusing on relationships among spiders have both reinforced and upturned long-standing hypotheses. Likewise, the evolution of spider webs-perhaps their most emblematic attribute-is being understood in new ways. With a matrix including 272 spider species and close arachnid relatives, we analyze and evaluate the relationships among these lineages using a variety of orthology assessment methods, occupancy thresholds, tree inference methods and support metrics.

Interrogating Genomic-Scale Data to Resolve Recalcitrant Nodes in the Spider Tree of Life.

Genome-scale data sets are converging on robust, stable phylogenetic hypotheses for many lineages; however, some nodes have shown disagreement across classes of data. We use spiders (Araneae) as a system to identify the causes of incongruence in phylogenetic signal between three classes of data: exons (as in phylotranscriptomics), noncoding regions (included in ultraconserved elements [UCE] analyses), and a combination of both (as in UCE analyses). Gene orthologs, coded as amino acids and nucleotides (with and without third codon positions), were generated by querying published transcriptomes for UCEs, recovering 1,931 UCE loci (codingUCEs).

Nylanderia of the World Part III: Nylanderia in the West Indies.

The diversity of the formicine ant genus Nylanderia is currently underestimated and largely undescribed. This includes the faunas of tropical regions where species richness is typically high. Here, the taxonomy of the West Indian Nylanderia fauna is revised for the first time.

Monophyly, Taxon Sampling, and the Nature of Ranks in the Classification of Orb-Weaving Spiders (Araneae: Araneoidea).

We address some of the taxonomic and classification changes proposed by Kuntner et al. (2019) in a comparative study on the evolution of sexual size dimorphism in nephiline spiders. Their proposal to recircumscribe araneids and to rank the subfamily Nephilinae as a family is fundamentally flawed as it renders the family Araneidae paraphyletic.

Phylogenomics, Diversification Dynamics, and Comparative Transcriptomics across the Spider Tree of Life.

Dating back to almost 400 mya, spiders are among the most diverse terrestrial predators [1]. However, despite considerable effort [1-9], their phylogenetic relationships and diversification dynamics remain poorly understood. Here, we use a synergistic approach to study spider evolution through phylogenomics, comparative transcriptomics, and lineage diversification analyses.

A phylotranscriptomic backbone of the orb-weaving spider family Araneidae (Arachnida, Araneae) supported by multiple methodological approaches.

The orb-weaving spider family Araneidae is extremely diverse (>3100 spp.) and its members can be charismatic terrestrial arthropods, many of them recognizable by their iconic orbicular snare web, such as the common garden spiders. Despite considerable effort to better understand their backbone relationships based on multiple sources of data (morphological, behavioral and molecular), pervasive low support remains in recent studies.

Redescription of the Jamaican orb-weaving spider Chrysometa pecki Levi, 1986 (Araneae, Tetragnathidae), including the first description of the male.

The tetragnathid genus Chrysometa Simon, 1894 includes 138 species found in the Americas, ranging from the Caribbean to Chile (World Spider Catalog 2015). This genus was revised by Levi (1986), with more recent publications adding to the genus (Álvarez-Padilla 2007, Nogueira et al. 2011, Simó et al.

The importance of using multiple approaches for identifying emerging invasive species: the case of the Rasberry Crazy Ant in the United States.

In the past decade, Houston, Texas has been virtually overrun by an unidentified ant species, the sudden appearance and enormous population sizes and densities of which have received national media attention. The Rasberry Crazy Ant, as it has become known due to its uncertain species status, has since spread to neighboring states and is still a major concern to pest control officials. Previous attempts at identifying this species have resulted in widely different conclusions in regards to its native range, source, and biology.