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  • 1.
    Gren, Johan A.
    et al.
    Lund University, Sweden.
    Sjövall, Peter
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry, Materials and Surfaces.
    Eriksson, Mats E.
    Lund University, Sweden.
    Sylvestersen, Rene L.
    MUSERUM, Denmark.
    Marone, Frederica
    Paul Scherrer Institute, Switzerland.
    Sigfridsson Clauss, Kajsa G. V.
    MAX IV Laboratory, Sweden.
    Taylor, Gavin J.
    Lund University, Sweden.
    Carlson, Stefan
    MAX IV Laboratory, Sweden.
    Uvdal, Per
    Lund University, Sweden.
    Lindgren, Johan
    Lund University, Sweden.
    Molecular and microstructural inventory of an isolated fossil bird feather from the Eocene Fur Formation of Denmark2017In: Palaeontology, ISSN 0031-0239, E-ISSN 1475-4983, Vol. 60, no 1, p. 73-90Article in journal (Refereed)
    Abstract [en]

    An isolated, yet virtually intact contour feather (FUM-1980) from the lower Eocene Fur Formation of Denmark was analysed using multiple imaging and molecular techniques, including field emission gun scanning electron microscopy (FEG-SEM), X-ray absorption spectroscopy and time-of-flight secondary ion mass spectrometry (ToF-SIMS). Additionally, synchrotron radiation X-ray tomographic microscopy (SRXTM) was employed in order to produce a digital reconstruction of the fossil. Under FEG-SEM, the proximal, plumulaceous part of the feather revealed masses of ovoid microstructures, about 1.7 μm long and 0.5 μm wide. Microbodies in the distal, pennaceous portion were substantially smaller (averaging 0.9 × 0.2 μm), highly elongate, and more densely packed. Generally, the microbodies in both the plumulaceous and pennaceous segments were aligned along the barbs and located within shallow depressions on the exposed surfaces. Biomarkers consistent with animal eumelanins were co-localized with the microstructures, to suggest that they represent remnant eumelanosomes (i.e. eumelanin-housing cellular organelles). Additionally, ToF-SIMS analysis revealed the presence of sulfur-containing organics – potentially indicative of pheomelanins – associated with eumelanin-like compounds. However, since there was no correlation between melanosome morphology and sulfur content, we conclude these molecular structures derive from diagenetically incorporated sulfur rather than pheomelanin. Melanosomes corresponding roughly in both size and morphology with those in the proximal part of FUM-1980 are known from contour feathers of extant parrots (Psittaciformes), an avian clade that has previously been reported from the Fur Formation.

  • 2. Labandeira, C. C.
    et al.
    Yang, Q.
    Santiago-Blay, J. A.
    Hotton, C. L.
    Monteiro, A.
    Wang, Y. -J
    Goreva, Y.
    Shih, C. K.
    Siljeström, Sandra
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor, Medicinteknik.
    Rose, T. R.
    Dilcher, D. L.
    Ren, D.
    The evolutionary convergence of mid-mesozoic lacewings and cenozoic butterflies2016In: Proceedings of the Royal Society of London. Biological Sciences, ISSN 0962-8452, E-ISSN 1471-2954, Vol. 283, no 1824, article id 20152893Article in journal (Refereed)
    Abstract [en]

    Mid-Mesozoic kalligrammatid lacewings (Neuroptera) entered the fossil record 165 million years ago (Ma) and disappeared 45 Ma later. Extant papilionoid butterflies (Lepidoptera) probably originated 80–70 Ma, long after kalligrammatids became extinct. Although poor preservation of kalligrammatid fossils previously prevented their detailed morphological and ecological characterization, we examine new, well-preserved, kalligrammatid fossils from Middle Jurassic and Early Cretaceous sites in northeastern China to unravel a surprising array of similar morphological and ecological features in these two, unrelated clades. We used polarized light and epifluorescence photography, SEM imaging, energy dispersive spectrometry and time-of-flight secondary ion mass spectrometry to examine kalligrammatid fossils and their environment. We mapped the evolution of specific traits onto a kalligrammatid phylogeny and discovered that these extinct lacewings convergently evolved wing eyespots that possibly contained melanin, and wing scales, elongate tubular proboscides, similar feeding styles, and seed–plant associations, similar to butterflies. Long-proboscid kalligrammatid lacewings lived in ecosystems with gymnosperm–insect relationships and likely accessed bennettitalean pollination drops and pollen. This system later was replaced by mid-Cretaceous angiosperms and their insect pollinators.

  • 3. Lindgren, J.
    et al.
    Moyer, A.
    Schweitzer, M. H.
    Sjövall, Peter
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor, Medicinteknik.
    Uvdal, P.
    Nilsson, D. E.
    Heimdal, J.
    Engdahl, A.
    Gren, J. A.
    Schultz, B. P.
    Kear, B. P.
    Interpreting melanin-based coloration through deep time: A critical Review2015In: Proceedings of the Royal Society of London. Biological Sciences, ISSN 0962-8452, E-ISSN 1471-2954, Vol. 282, no 1813, article id 20150614Article, review/survey (Refereed)
    Abstract [en]

    Colour, derived primarily from melanin and/or carotenoid pigments, is integral to many aspects of behaviour in living vertebrates, including social signalling, sexual display and crypsis. Thus, identifying biochromes in extinct animals can shed light on the acquisition and evolution of these biological traits. Both eumelanin and melanin-containing cellular organelles (melanosomes) are preserved in fossils, but recognizing traces of ancient melanin-based coloration is fraught with interpretative ambiguity, especially when observations are based on morphological evidence alone. Assigning microbodies (or, more often reported, their ‘mouldic impressions’) as melanosome traces without adequately excluding a bacterial origin is also problematic because microbes are pervasive and intimately involved in organismal degradation. Additionally, some forms synthesize melanin. In this review, we survey both vertebrate and microbial melanization, and explore the conflicts influencing assessment of microbodies preserved in association with ancient animal soft tissues.We discuss the types of data used to interpret fossil melanosomes and evaluate whether these are sufficient for definitive diagnosis. Finally, we outline an integrated morphological and geochemical approach for detecting endogenous pigment remains and associated microstructures in multimillion-year-old fossils.

  • 4. Lindgren, J.
    et al.
    Sjövall, Peter
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor, Medicinteknik.
    Carney, R. M.
    Cincotta, A.
    Uvdal, P.
    Hutcheson, S. W.
    Gustafsson, O.
    Lefèvre, U.
    Escuillié, F.
    Heimdal, J.
    Engdahl, A.
    Gren, J. A.
    Kear, B. P.
    Wakamatsu, K.
    Yans, J.
    Godefroit, P.
    Molecular composition and ultrastructure of Jurassic paravian feathers2015In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 5, article id 13520Article in journal (Refereed)
    Abstract [en]

    Feathers are amongst the most complex epidermal structures known, and they have a well-documented evolutionary trajectory across non-avian dinosaurs and basal birds. Moreover, melanosome-like microbodies preserved in association with fossil plumage have been used to reconstruct original colour, behaviour and physiology. However, these putative ancient melanosomes might alternatively represent microorganismal residues, a conflicting interpretation compounded by a lack of unambiguous chemical data. We therefore used sensitive molecular imaging, supported by multiple independent analytical tests, to demonstrate that the filamentous epidermal appendages in a new specimen of the Jurassic paravian Anchiornis comprise remnant eumelanosomes and fibril-like microstructures, preserved as endogenous eumelanin and authigenic calcium phosphate. These results provide novel insights into the early evolution of feathers at the sub-cellular level, and unequivocally determine that melanosomes can be preserved in fossil feathers.

  • 5. Maldanis, L.
    et al.
    Carvalho, M.
    Ramos Almeida, M.
    Freitas, F. I.
    De Andrade, J. A. F. G.
    Nunes, R. S.
    Rochitte, C. E.
    Poppi, R. J.
    Freitas, R. O.
    Rodrigues, F.
    Siljeström, Sandra
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor, Medicinteknik.
    Alves Lima, F.
    Galante, D.
    Carvalho, I. S.
    Perez, C. A.
    de Carvalho, M. R.
    Bettini, J.
    Fernandez, V.
    Xavier-Neto, J.
    Heart fossilization is possible and informs the evolution of cardiac outflow tract in vertebrates2016In: eLIFE, E-ISSN 2050-084X, Vol. 5, no APRIL2016, article id e14698Article in journal (Refereed)
    Abstract [en]

    Elucidating cardiac evolution has been frustrated by lack of fossils. One celebrated enigma in cardiac evolution involves the transition from a cardiac outflow tract dominated by a Multi-Valved conus arteriosus in basal actinopterygians, to an outflow tract commanded by the Non- Valved, elastic, bulbus arteriosus in higher actinopterygians. We demonstrate that cardiac preservation is possible in the extinct fish Rhacolepis buccalis from the Brazilian Cretaceous. Using X-Ray synchrotron microtomography, we show that Rhacolepis fossils display hearts with a conus arteriosus containing at least five valve rows. This represents a transitional morphology between the primitive, multivalvar, conal condition and the derived, monovalvar, bulbar state of the outflow tract in modern actinopterygians. Our data rescue a Long-Lost cardiac phenotype (119-113 Ma) and suggest that outflow tract simplification in actinopterygians is compatible with a gradual, rather than a drastic saltation event. Overall, our results demonstrate the feasibility of studying cardiac evolution in fossils.

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