New methods in taxonomy and systematics can influence the overall practice of formally naming and describing biodiversity. DNA barcoding has been controversial since its emergence, but now, large scale species descriptions exclusively based on barcodes have created what can be called a ‘new quality of performance’. Its limitations are discussed from different perspectives: nomenclature, general pragmatism, and problems of DNA-based species delimitation in the light of the central aim of achieving a robust and stable nomenclature of organisms, essential for all applications of biodiversity research. This issue needs to be addressed to prevent restraining the progress of taxonomy and its ability to contribute to modern science.

Microhabitat changes are thought to be among the main drivers of diversification. However, this conclusion is mostly based on studies on vertebrates. Here, we investigate the influence of microhabitat on diversification rates in pholcid spiders (Araneae, Pholcidae). Diversification analyses were conducted in the framework of the largest molecular phylogeny of pholcid spiders to date based on three nuclear and three mitochondrial loci from 600 species representing more than 85% of the currently described pholcid genera. Assessments of ancestral microhabitat revealed frequent evolutionary change. In particular, within the largest subfamily Pholcinae, numerous changes from near-ground habitats towards leaves and back were found. In general, taxa occupying leaves and large sheltered spaces had higher diversification rates than ground-dwelling taxa. Shifts in speciation rate were found in leaf- and space-dwelling taxa. Our analyses result in one of the most comprehensive phylogenies available for a major spider family and provide a framework for any subsequent studies of pholcid spider biology. Diversification analyses strongly suggest that microhabitat is an important factor influencing diversification patterns in pholcid spiders.

Species are the fundamental units of life and evolution. Their recognition is essential for science and society. Molecular methods have been increasingly used for the identification of animal species, despite several challenges. Here, we explore with genomic data from nine animal lineages a set of nuclear markers, namely metazoan‐level universal single‐copy orthologs (metazoan USCOs), for their use in species delimitation. Our data sets include arthropods and vertebrates. We use various data assembly strategies and use coalescent‐based species inference as well as population admixture analyses and phenetic methods. We demonstrate that metazoan USCOs distinguish well closely related morphospecies and consistently outperform classical mitochondrial DNA barcoding in discriminating closely related species in different animal taxa, as judged by comparison with morphospecies delimitations. USCOs overcome the general shortcomings of mitochondrial DNA barcodes, and due to standardization across Metazoa, also those of other approaches. They accurately assign samples not only to lower but also to higher taxonomic levels. Metazoan USCOs provide a powerful and unifying framework for DNA‐based species delimitation and taxonomy in animals and their employment could result in a more efficient use of research data and resources.

In recent years, large‐scale DNA barcoding campaigns have generated an enormous amount of COI barcodes, which are usually stored in NCBI's GenBank and the official Barcode of Life database (BOLD). BOLD data are generally associated with more detailed and better curated meta‐data, because a great proportion is based on expert‐verified and vouchered material, accessible in public collections. In the course of the initiative German Barcode of Life data were generated for the reference library of 2,846 species of Coleoptera from 13,516 individuals. Confronted with the high effort associated with the identification, verification and data validation, a bioinformatic pipeline, “TaxCI” was developed that (1) identifies taxonomic inconsistencies in a given tree topology (optionally including a reference dataset), (2) discriminates between different cases of incongruence in order to identify contamination or misidentified specimens, (3) graphically marks those cases in the tree, which finally can be checked again and, if needed, corrected or removed from the dataset. For this, “TaxCI” may use DNA‐based species delimitations from other approaches (e.g. mPTP) or may perform implemented threshold‐based clustering. The data‐processing pipeline was tested on a newly generated set of barcodes, using the available BOLD records as a reference. A data revision based on the first run of the TaxCI tool resulted in the second TaxCI analysis in a taxonomic match ratio very similar to the one recorded from the reference set (92% vs. 94%). The revised dataset improved by nearly 20% through this procedure compared to the original, uncorrected one. Overall, the new processing pipeline for DNA barcode data allows for the rapid and easy identification of inconsistencies in large datasets, which can be dealt with before submitting them to public data repositories like BOLD or GenBank. Ultimately, this will increase the quality of submitted data and the speed of data submission, while primarily avoiding the deterioration of the accuracy of the data repositories due to ambiguously identified or contaminated specimens.

This study explores the potential use of photos for extracting basic data on spider eggs and presents a first rough but comprehensive overview of egg sizes, egg numbers per egg sac, and egg sac shapes in 468 species of pholcid spiders representing 73 genera. Egg diameters ranged 0.29–1.73 mm; egg numbers ranged 3–110. Egg sacs were mostly round or oval, but tended to be elongated in species with elongated abdomens, and flattened in very short‐legged species. Potential effects of female body size, abdomen shape, and microhabitat on egg size and number were evaluated by phylogenetic generalized linear models across all investigated species. Our analyses showed that both egg size and egg number are strongly determined by female body size. We found a clear trend for small species to have relatively larger eggs. Ecology and body shape also played a role, albeit at a considerably lower level and with complex interactions among variables: Relative to body size, ground‐dwelling species had smaller eggs than space and leaf dwellers; species with a long abdomen had larger eggs than species with a short abdomen. The effect of body size on clutch size depended on body shape and microhabitat: It was slightly weaker in space‐dwelling than in other species; species with long abdomens had more eggs in ground and leaf microhabitats, whereas space dwellers carried more eggs when having short abdomens.