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The genus Spaeleoleptes was proposed by H. Soares in 1966 to accommodate the first Brazilian troglobitic species of harvestmen, Spaeleoleptes spaeleus H. Soares, 1966. In this work, we redescribe this species, including digital images of the type material and drawings of the male genitalia. Since its description, Spaeleoleptes has remained monotypic, and after 56 years, herein is described the second species of the genus, the troglobitic Spaeleoleptes gimli sp. nov. Both species share sexually dimorphic legs I and II with modified regions and swelling on the tibiae and patellae I and II; a penis with robust conductors covering all or part of the capsula interna and a capsula interna with two lateral projections. They are clearly separated by the shape of the modified region of the tibia; by the presence of an apical projection on the apical lamina of the pars distalis in S. spaeleus; and the lateral projections of the capsula interna, which is flattened in S. gimli. Spaeleoleptes gimli greatly increases the distributional range of the genus, as it is now recorded from caves located in two Brazilian phytophysiognomies from the Cerrado of Minas Gerais to the Caatinga of Bahia.
Two species new to science Willowsia sikkimensis sp. nov. and W. arunachalensis sp. nov., and one new record of the genus Willowsia Shoebotham, 1917 are described and illustrated here. The new species are mainly distinguished from the others on the basis of pigment pattern, scale type and chaetotaxy. The species were collected from the states of Arunachal Pradesh and Sikkim (India). Willowsia shiae Pan, Zhang & Chen, 2006 is recorded for the first time from India (Arunachal Pradesh) and redescribed with detailed chaetotaxic nomenclature. A key to the Indian species of Willowsia and a comparison table of related species are also provided.
In this second part of the study, using a ‘clean’ dataset without very low precision landmarks and outliers, I describe how to compare mandibular size and shape using Procrustes methods in adult North American marmots. After demonstrating that sex differences are negligible, females and males are pooled together with specimens of unknown sex and species are compared using a battery of tests, that estimate both statistical significance and effect size. The importance of allometric variation and its potential effect on shape differences is also explored. Finally, to provide potential clues on founder effects, I compare the magnitude of variance in mandibular size and shape between the Vancouver Island marmot (VAN) and the hoary marmot, its sister species on the mainland. In almost all main analyses, I explore the sensitivity of results to heterogeneous sample size and small samples using subsamples and randomized selection experiments. For both size and shape, I find a degree of overlap among species variation but, with very few exceptions, mean interspecific differences are well supported in all analyses. Shape, in particular, is an accurate predictor of taxonomic affiliation. Allometry in adults, however, explains a modest amount of within-species shape change. Yet, there is a degree of divergence in allometric trajectories that seems consistent with subgeneric separation. VAN is the most distinctive species for mandibular shape and mandibular morphology suggests a long history of reduced variation in this insular population. Geometric morphometrics (GMM) is a powerful tool to aid taxonomic research. Regardless of the effectiveness of this family of methods and the apparent robustness of results obtained with GMM, however, large samples and careful measurements remain essential for accuracy. Even with excellent data, morphometrics is important, but its findings must be corroborated with an integrative approach that combines multiple lines of evidence to taxonomic assessment. The analytical protocol I suggest is described in detail, with a summary checklist, in the Appendix, not to miss important steps. All the analyses can be replicated using the entire dataset, which is freely available online. Beginners may follow all the steps, whereas more experienced researchers can focus on one specific aspect and read only the relevant chapter. There are limitations, but the protocol is flexible and easy to improve or implement using a programming language such as R.