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Disparities in the analysis of morphological disparity
Get PDFAnalyses of morphological disparity have been used to characterize and investigate the evolution of variation in the anatomy, function and ecology of organisms since the 1980s. While a diversity of methods have been employed, it is unclear whether they provide equivalent insights. Here, we review the most commonly used approaches for characterizing and analysing morphological disparity, all of which have associated limitations that, if ignored, can lead to misinterpretation. We propose best practice guidelines for disparity analyses, while noting that there can be no ‘one-size-fits-all’ approach. The available tools should always be used in the context of a specific biological question that will determine data and method selection at every stage of the analysis.Published by the Royal Society under the terms of the Creative Commons Attribution License http://creativecommons.org/licenses/by/4.0/, which permits unrestricted use, provided the original author and source are credited.NHM Repositor
The role of arc migration in the development of the Lesser Antilles: A new tectonic model for the Cenozoic evolution of the eastern Caribbean
Get PDFPublished version so can't be available open access at presentContinental arc systems often show evidence of large-scale migration both toward and away from the incoming plate. In oceanic arc systems, however, while slab roll-back and the associated processes of backarc spreading and arc migration toward the incoming plate are commonplace, arc migration away from the incoming plate is rarely observed. We present a new compilation of marine magnetic anomaly and seismic data in order to propose a new tectonic model for the eastern Caribbean region that includes arc migration in both directions. We synthesized new evidence to show two phases of backarc spreading and eastward arc migration toward the incoming Atlantic. A third and final phase of arc migration to the west subdivided the earlier backarc basin on either side of the present-day Lesser Antilles arc. This is the first example of regional multidirectional arc migration in an intra-oceanic setting, and it has implications for along-arc structural and geochemical variations. The back and forth arc migrations were probably due to the constraints imposed by the neighboring American plates on this isolated subduction system, rather than variations in subducting slab buoyancy.© 2019 The Authors. Gold Open Access: This paper is published under the terms of the CC-BY license.NHM Repositor
Extensive sampling and thorough taxonomic assessment of Afrotropical Rhyssinae (Hymenoptera, Ichneumonidae) reveals two new species and demonstrates the limitations of previous sampling efforts
Get PDFTropical forest invertebrates, such as the parasitoid wasp family Ichneumonidae, are poorly known. This work reports some of the first results of an extensive survey implemented in Kibale National Park, Uganda. A total of 456 individuals was caught of the subfamily Rhyssinae Morley, 1913, which in the Afrotropical region was previously known from only 30 specimens. Here, the six species found at the site are described and the Afrotropical Rhyssinae are reviewed. Two new species, Epirhyssa johanna Hopkins, sp. nov. and E. quagga sp. nov., are described and a key, diagnostic characters, and descriptions for all 13 known Afrotropical species are provided, including the first description of the male of Epirhyssa overlaeti Seyrig, 1937. Epirhyssa gavinbroadi Rousse & van Noort, 2014, syn. nov. is proposed to be a synonym of E. uelensis Benoit, 1951. Extensive sampling with Malaise traps gave an unprecedented sample size, and the method is recommended for other poorly known tropical areas.This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. The attached file is the published pdf.NHM Repositor
A review of the genus Chrysocryptus Cameron (Ichneumonidae: Phygadeuontinae), with description of a new species
Get PDFThe phygadeuontine genus Chrysocryptus (Ichneumonidae) is reviewed for the first time on the basis of ichneumonid collections in the Institute of Ecology and Biological Resources, Hanoi (Vietnam), the Natural History Museum, London (UK), and the Naturalis Biodiversity Center, Leiden (the Netherlands). A new species, Chrysocryptus brevis, is described from northern Vietnam. In addition, C. aureopilosus is recorded for the first time from Vietnam and from Indonesia (West Java). A key to all four known species of the genus Chrysocryptus is included.© National University of Singapore. This is an openly available article, available to all readers online. The attached file is the published version of the article.NHM Repositor
Eutrophication erodes inter-basin variation in macrophytes and co-occurring invertebrates in a shallow lake: combining ecology and palaeoecology
Get PDFAquatic biodiversity is commonly linked with environmental variation in lake networks, but less is known about how local factors may influence within-lake biological heterogeneity. Using a combined ecological and multi-proxy palaeoecological approach we investigated long-term changes in the pathways and processes that underlie eutrophication and water depth effects on lake macrophyte and invertebrate communities across three basins in a shallow lake—Castle Lough, Northern Ireland, UK. Contemporary data allow us to assess how macrophyte assemblages vary in composition and heterogeneity according to basin-specific factors (e.g. variation in water depth), while palaeoecological data (macrophytes and co-occurring invertebrates) enable us to infer basin-specific impacts and susceptibilities to nutrient-enrichment. Results indicate that variability in water depth promotes assemblage variation amongst the lake basins, stimulating within-lake macrophyte assemblage heterogeneity and hence higher lake biodiversity. The palaeo-data indicate that eutrophication has acted as a strong homogenising agent of macrophyte and invertebrate diversities and abundances over time at the whole-lake scale. This novel finding strongly suggests that, as eutrophication advances, the influence of water depth on community heterogeneity is gradually eroded and that ultimately a limited set of eutrophication-tolerant species will become homogeneously distributed across the entire lake.© Springer Science+Business Media Dordrecht 2017. This is a post-peer-review, pre-copyedit version of an article published in Journal of Paleolimnology. The final authenticated version is available online at: http://dx.doi.org/0.1007/s10933-017-9950-6. You are advised to consult the publisher’s version if you wish to cite from it.NHM Repositor
Solanum medusae (Solanaceae), a new wolf-fruit from Brazil, and a key to the extra-Amazonian Brazilian Androceras/Crinitum Clade species
Get PDFSolanum medusae sp. nov. is described from the Cerrado biome in the Serra da Canastra region, southwestern Minas Gerais State, Brazil. The new species is morphologically similar to the common S. lycocarpum A.St.-Hil. (known as lobeira or wolf-fruit), but differs from it in habit and pubescence characters. We here describe this new taxon and discuss its morphology, some aspects of its ecology, affinities and distribution. Full specimen citations are provided, as well as illustrations, distribution map and a preliminary conservation assessment of the species. A key to all of the known extra-Amazonian Brazilian species of the Androceras/Crinitum clade is also provided to aid in their identification.This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.NHM Repositor
Perspectives in Animal Phylogeny and Evolution: A decade later
Get PDFRefinements in phylogenomic methods and novel data have clarified several
controversies in animal phylogeny that were intractable with traditional PCR-based
approaches or early Next Gen analyses. An alliance between Placozoa and Cnidaria has
recently found support. Data from newly discovered species of Xenoturbella contribute
to Xenacoelomorpha being placed as sister group of Nephrozoa rather than within the
deuterostomes. Molecular data reinforce the monophyly of Gnathifera and ally the longenigmatic chaetognaths with them. Platyzoa was an artefactual grouping, and deep
relationships within Spiralia now depict Rouphozoa (= Gastrotricha + Platyhelminthes)
as sister group to Lophotrochozoa, and Gnathifera (plus Chaetognatha) their immediate
sister group. A “divide and conquer” strategy of subsampling clades to optimize gene
selection may be needed to simultaneously resolve the many disparate clades of the
animal tree of lifeFirst edition 2019, Padova University Press © 2019 Padova University Press, Università degli Studi di Padova via 8 Febbraio 2, Padova This item is freely available.NHM Repositor
The chemical basis of a signal of individual identity: shell pigment concentrations track the unique appearance of Common Murre eggs.
Get PDFIn group-living species with parental care, the accurate recognition of one's own young is critical to fitness. Because discriminating offspring within a large colonial group may be challenging, progeny of colonial breeders often display familial or individual identity signals to elicit and receive parental provisions from their own parents. For instance, the common murre (or common guillemot: Uria aalge) is a colonially breeding seabird that does not build a nest and lays and incubates an egg with an individually unique appearance. How the shell's physical and chemical properties generate this individual variability in coloration and maculation has not been studied in detail. Here, we quantified two characteristics of the avian-visible appearance of murre eggshells collected from the wild: background coloration spectra and maculation density. As predicted by the individual identity hypothesis, there was no statistical relationship between avian-perceivable shell background coloration and maculation density within the same eggs. In turn, variation in both sets of traits was statistically related to some of their physico-chemical properties, including shell thickness and concentrations of the eggshell pigments biliverdin and protoporphyrin IX. These results illustrate how individually unique eggshell appearances, suitable for identity signalling, can be generated by a small number of structural mechanisms.& 2019 The Author(s) Published by the Royal Society. All rights reserved. This document is the authors' final accepted version of the journal article. You are advised to consult the published version if you wish to cite from it.NHM Repositor
Postcranial osteology of the neotype specimen of Massospondylus carinatus Owen, 1854 (Dinosauria: Sauropodomorpha) from the upper Elliot formation of South Africa
Get PDFOA published versionMassospondylus carinatus Owen, 1854, from the earliest Jurassic upper Elliot Formation of South Africa, was one of the first dinosaurs to be described from Gondwana. It has been incorporated into numerous phylogenetic, palaeobiological and biostratigraphic analyses, is often viewed as an exemplar for understanding sauropodomorph anatomy and is a key taxon in studies of early dinosaur evolution. Since its initial description, numerous specimens have been referred to this species, ranging from isolated postcranial elements to complete skeletons with three-dimensional skulls. In addition,M. carinatus has been identified in areas outside of the main Karoo Basin. Surprisingly, however, there have been few attempts to define the taxon rigorously, so that the basis for many of these referrals is weak, undermining the utility of this abundant material. Here, we provide the first detailed postcranial description of the neotype specimen of M. carinatus, use it as a basis for diagnosing the species on the basis of cranial, axial and appendicular characters, demonstrate that it represents an adult individual on the basis of osteohistology, and discuss ways in which these data can assist in providing a better understanding of Karoo-aged African dinosaur faunas.Palaeontologia africana 2019. ©2019 Paul M. Barrett, Kimberley E. J. Chapelle, Casey K. Staunton, Jennifer Botha & Jonah N. Choiniere. This is an open-access article published under the Creative Commons Attribution 4.0 Unported License (CC BY4.0). To view a copy of the license, please visit http://creativecommons.org/licenses/ by/4.0/. This license permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. The article and five supplements are permanently archived at: http://wiredspace.wits.ac.za/handle/10539/26829. The attached article is the published pdf.NHM Repositor
How has the environment shaped geographical patterns of insect body sizes? A test of hypotheses using sphingid moths.
Get PDFAim: We mapped the geographical pattern of body sizes in sphingid moths and investigated latitudinal clines. We tested hypotheses concerning their possible environmental control, that is, effects of temperature (negative: temperature size rule or Bergmann's rule; positive: converse Bergmann rule), food availability, robustness to starvation during extreme weather and seasonality. Location: Old World and Australia/Pacific region. Methods: Body size data of 950 sphingid species were compiled and related to their distribution maps. Focusing on body length, we mapped the median and maximum size of all species occurring in 100 km grid cells. In a comparative approach, we tested the predictions from explanatory hypotheses by correlating species' size to the average environmental conditions encountered throughout their range, under univariate and multivariate models. We accounted for phylogeny by stepwise inclusion of phylogenetically informed taxonomic classifications into hierarchical random‐intercept mixed models. Results: Median body sizes showed a distinctive geographical pattern, with large species in the Middle East and the Asian tropics, and smaller species in temperate regions and the Afrotropics. Absolute latitude explained very little body size variation, but there was a latitudinal cline of maximum size. Species' median size was correlated with net primary productivity, supporting the food availability hypothesis, whereas support for other hypotheses was weak. Environmental correlations contributed much less (i.e. 70% of variability). Main conclusion: The intuitive impression of larger species in the tropics is shaped by larger size maxima. Median body sizes are only very weakly related to latitude. Most of the geographical variation in body size in sphingid moths is explained by their phylogenetic past. NPP and forest cover correlate positively with the body size, which supports the idea that food availability allowed the evolution of larger sizes.Copyright © 2019 John Wiley & Sons Ltd. This is the pre-peer reviewed version of the following article: Beerli, N, Bärtschi, F, Ballesteros‐Mejia, L, Kitching, IJ, Beck, J. How has the environment shaped geographical patterns of insect body sizes? A test of hypotheses using sphingid moths. J Biogeogr. 2019; 46: 1687– 1698, which has been published in final form at https://doi.org/10.1111/jbi.13583. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-ArchivingNHM Repositor