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Not AvailableThis study investigates the evolution of locomotory morphology and migratory behavior in nightingale-thrushes (genus Catharus), a clade of songbirds with diverse migratory strategies. With large datasets of molecular and morphometric characters, we resolve phylogenetic relationships, identify and model migration-related morphological characters, and estimate ancestral states of those characters to infer evolutionary transitions in the migratory phenotype. While acknowledging that unknown factors (e.g., differential extinction) may confound interpretation, our results suggest that (1) migratory behavior and its functional morphology are fundamentally linked; (2) short-distance or elevational migration (not long-distance) was the ancestral state of Catharus; (3) short-distance migration was the evolutionary precursor of long-distance migration; and (4) the short-distance migrant, Hermit Thrush (C. guttatus), may be in relative phenotypic (ecological) stasis. This potentially explains the ecological incumbency of C. guttatus in temperate North America during winter, and offers a new framework for interpreting the evolutionary sequence that produced long-distance migration in this model system. 

Abstract Parasitic lice (Psocodea: Phthiraptera) are small, wingless parasites of birds and mammals that have been at the forefront of coevolutionary studies since the 1990s, and at the forefront of human–insect interactions since the dawn of humankind. Despite this, an unfortunate overreliance on a co-radiation model of evolution between lice and their hosts (“Fahrenholz’s Rule”) has left a muddled legacy in their classification and taxonomy. In recent decades, the classifications of lice at the order, suborder, family, genus, and species levels have all been examined by a mixture of morphological, genetic, and genomic data, which have challenged many traditional taxon limits and relationships. Here, we discuss the traditional classification of parasitic lice, the data that challenged it, and our current understanding of the group. We give an overview of the morphological characters that identify the major radiations of lice, and point out a number of areas that need further work. 

Abstract Myrsidea Waterston, 1915 (Phthiraptera: Menoponidae) is the most diverse genus of avian chewing lice. Myrsidea has a global distribution, is thought to be highly host-specific, and parasitizes mostly passerine birds. However, the rate of taxonomic studies describing new species is relatively low, and it is thought that much of the diversity of Myrsidea is yet to be discovered. This low rate of taxonomic description for this genus, and many others, may be related to the time-consuming nature of morphological species description and a lack of expertise in louse taxonomy. Furthermore, most of the taxonomic revisions and reviews have focused on specific host families, and no comprehensive review of the morphology and molecular work of Myrsidea has been completed in the last 20 years. Here, we review the taxonomy and systematics of Myrsidea to (i) describe this chewing louse genus and its biological importance; (ii) describe current problems with its taxonomy; (iii) simplify and summarize morphological descriptions; (iv) summarize molecular data; and (v) provide a comprehensive checklist of the Myrsidea species, with all publications and localities of occurrence included. Together, we hope that this information will provide researchers with a single source of information on the genus Myrsidea, making it easier for work to proceed on its taxonomy, systematics, ecology, and evolution. Importantly, our work highlights important gaps in our knowledge of Myrsidea, providing guideposts on where future work on Myrsidea is needed. 

This paper provides a catalogue of the type specimens of lice (Insecta: Psocodea: Phthiraptera) held in the collection of the Field Museum of Natural History (FMNH), Chicago, Illinois, USA. There are 178 nominal species, four of which are represented by holotype only; 14 by holotype, allotype and paratypes; 29 by holotype and paratypes; 127 by paratypes only; three by neoparatypes, and one by paralectotype. The main goal of this type catalog is to make the louse type specimens and their metadata more readily available to biodiversity researchers. 

Abstract We reconstruct the species-level phylogenetic relationship among toucans, toucan-barbets, New World barbets using phylogenomic data to assess the monophyly and relationships at the family, generic, and specific levels. Our analyses confirmed (1) the monophyly of toucans (Aves: Ramphastidae), toucan-barbets (Aves: Semnornithidae), and New World barbets (Aves: Capitonidae) and that the toucan-barbets are sister to the toucans, an arrangement suggested, but poorly supported, in previously published phylogenies; (2) the paraphyly of lowland Selenidera toucanets with respect to Andigena mountain-toucans; and (3) evidence of some mitonuclear discordance, suggesting introgression or incomplete lineage sorting. For example, mitonuclear conflict in the phylogenetic placement of Ramphastos vitellinus subspecies suggests that Amazonian populations of Ramphastos vitellinus ariel may have introgressed mitogenomes derived from other Amazonian vitellinus taxa. To reconstruct the phylogenetic history of toucans, toucan-barbets, and New World barbets, we included all species-level taxa from the three families, with the addition of outgroups from the two major clades of Old World barbets (Megalaimidae and Lybiidae). We analyzed a combination of UCE sequences and whole mitochondrial genome sequences to reconstruct phylogenetic trees.