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Falk D, Wings O, Unitt R, Wade J, McNamara ME. Fossilized anuran soft tissues reveal a new taphonomic model for the Eocene Geiseltal Konservat-Lagerstätte, Germany. Sci Rep 2024; 14:7876. [PMID: 38654038 DOI: 10.1038/s41598-024-55822-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Accepted: 02/28/2024] [Indexed: 04/25/2024] Open
Abstract
The Eocene Geiseltal Konservat-Lagerstätte (Germany) is famous for reports of three dimensionally preserved soft tissues with sub-cellular detail. The proposed mode of preservation, direct replication in silica, is not known in other fossils and has not been verified using modern approaches. Here, we investigated the taphonomy of the Geiseltal anurans using diverse microbeam imaging and chemical analytical techniques. Our analyses confirm the preservation of soft tissues in all body regions but fail to yield evidence for silicified soft tissues. Instead, the anuran soft tissues are preserved as two layers that differ in microstructure and composition. Layer 1 comprises sulfur-rich carbonaceous microbodies interpreted as melanosomes. Layer 2 comprises the mid-dermal Eberth-Katschenko layer, preserved in calcium phosphate. In addition, patches of original aragonite crystals define the former position of the endolymphatic sac. The primary modes of soft tissue preservation are therefore sulfurization of melanosomes and phosphatization of more labile soft tissues, i.e., skin. This is consistent with the taphonomy of vertebrates in many other Konservat-Lagerstätten. These findings emphasize an emerging model for pervasive preservation of vertebrate soft tissues via melanosome films, particularly in stagnation-type deposits, with phosphatization of more labile tissues where tissue biochemistry is favorable.
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Affiliation(s)
- Daniel Falk
- School of Biological, Earth and Environmental Sciences, University College Cork, Distillery Fields, North Mall, Cork, T23 TK30, Ireland.
- Environmental Research Institute, University College Cork, Lee Rd, Cork, T23 XE10, Ireland.
| | - Oliver Wings
- Natural History Museum Bamberg, Staatliche Naturwissenschaftliche Sammlungen Bayerns, Fleischstraße 2, 96047, Bamberg, Germany
| | - Richard Unitt
- School of Biological, Earth and Environmental Sciences, University College Cork, Distillery Fields, North Mall, Cork, T23 TK30, Ireland
- Environmental Research Institute, University College Cork, Lee Rd, Cork, T23 XE10, Ireland
- Copper Coast UNESCO Global Geopark, Knockmahon, Bunmahon, X42 T923, Ireland
| | - Jon Wade
- Department of Earth Sciences, University of Oxford, South Parks Road, Oxford, OX1 3AN, UK
| | - Maria E McNamara
- School of Biological, Earth and Environmental Sciences, University College Cork, Distillery Fields, North Mall, Cork, T23 TK30, Ireland
- Environmental Research Institute, University College Cork, Lee Rd, Cork, T23 XE10, Ireland
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Slater TS, Ito S, Wakamatsu K, Zhang F, Sjövall P, Jarenmark M, Lindgren J, McNamara ME. Taphonomic experiments reveal authentic molecular signals for fossil melanins and verify preservation of phaeomelanin in fossils. Nat Commun 2023; 14:5651. [PMID: 37803012 PMCID: PMC10558522 DOI: 10.1038/s41467-023-40570-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Accepted: 08/01/2023] [Indexed: 10/08/2023] Open
Abstract
Melanin pigments play a critical role in physiological processes and shaping animal behaviour. Fossil melanin is a unique resource for understanding the functional evolution of melanin but the impact of fossilisation on molecular signatures for eumelanin and, especially, phaeomelanin is not fully understood. Here we present a model for the chemical taphonomy of fossil eumelanin and phaeomelanin based on thermal maturation experiments using feathers from extant birds. Our results reveal which molecular signatures are authentic signals for thermally matured eumelanin and phaeomelanin, which signatures are artefacts derived from the maturation of non-melanin molecules, and how these chemical data are impacted by sample preparation. Our model correctly predicts the molecular composition of eumelanins in diverse vertebrate fossils from the Miocene and Cretaceous and, critically, identifies direct molecular evidence for phaeomelanin in these fossils. This taphonomic framework adds to the geochemical toolbox that underpins reconstructions of melanin evolution and of melanin-based coloration in fossil vertebrates.
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Affiliation(s)
- Tiffany S Slater
- School of Biological, Earth and Environmental Sciences, University College Cork, Cork, Ireland.
- Environmental Research Institute, University College Cork, Cork, Ireland.
| | - Shosuke Ito
- Institute for Melanin Chemistry, Fujita Health University, Toyoake, Aichi, Japan
| | - Kazumasa Wakamatsu
- Institute for Melanin Chemistry, Fujita Health University, Toyoake, Aichi, Japan
| | - Fucheng Zhang
- Institute of Geology and Paleontology, Linyi University, Linyi City, Shandong, China
| | - Peter Sjövall
- RISE Research Institutes of Sweden, Materials and Production, 501 15, Borås, Sweden
| | | | - Johan Lindgren
- Department of Geology, Lund University, 223 62, Lund, Sweden
| | - Maria E McNamara
- School of Biological, Earth and Environmental Sciences, University College Cork, Cork, Ireland.
- Environmental Research Institute, University College Cork, Cork, Ireland.
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Cincotta A, Nicolaï M, Campos HBN, McNamara M, D'Alba L, Shawkey MD, Kischlat EE, Yans J, Carleer R, Escuillié F, Godefroit P. Pterosaur melanosomes support signalling functions for early feathers. Nature 2022; 604:684-688. [PMID: 35444275 PMCID: PMC9046085 DOI: 10.1038/s41586-022-04622-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Accepted: 03/07/2022] [Indexed: 01/10/2023]
Abstract
Remarkably well-preserved soft tissues in Mesozoic fossils have yielded substantial insights into the evolution of feathers1. New evidence of branched feathers in pterosaurs suggests that feathers originated in the avemetatarsalian ancestor of pterosaurs and dinosaurs in the Early Triassic2, but the homology of these pterosaur structures with feathers is controversial3,4. Reports of pterosaur feathers with homogeneous ovoid melanosome geometries2,5 suggest that they exhibited limited variation in colour, supporting hypotheses that early feathers functioned primarily in thermoregulation6. Here we report the presence of diverse melanosome geometries in the skin and simple and branched feathers of a tapejarid pterosaur from the Early Cretaceous found in Brazil. The melanosomes form distinct populations in different feather types and the skin, a feature previously known only in theropod dinosaurs, including birds. These tissue-specific melanosome geometries in pterosaurs indicate that manipulation of feather colour-and thus functions of feathers in visual communication-has deep evolutionary origins. These features show that genetic regulation of melanosome chemistry and shape7-9 was active early in feather evolution.
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Affiliation(s)
- Aude Cincotta
- Directorate Earth and History of Life, Royal Belgian Institute of Natural Sciences, Brussels, Belgium. .,Institute of Life, Earth and Environment, University of Namur, Namur, Belgium. .,School of Biological, Earth and Environmental Sciences, University College Cork, Cork, Ireland. .,Environmental Research Institute, University College Cork, Cork, Ireland.
| | - Michaël Nicolaï
- Evolution and Optics of Nanostructures Group, Biology Department, Ghent University, Ghent, Belgium
| | | | - Maria McNamara
- School of Biological, Earth and Environmental Sciences, University College Cork, Cork, Ireland. .,Environmental Research Institute, University College Cork, Cork, Ireland.
| | - Liliana D'Alba
- Evolution and Optics of Nanostructures Group, Biology Department, Ghent University, Ghent, Belgium.,Naturalis Biodiversity Center, Leiden, The Netherlands
| | - Matthew D Shawkey
- Evolution and Optics of Nanostructures Group, Biology Department, Ghent University, Ghent, Belgium
| | - Edio-Ernst Kischlat
- Divisão de Bacias Sedimentares, Geological Survey of Brazil, Porto Alegre, Brazil
| | - Johan Yans
- Institute of Life, Earth and Environment, University of Namur, Namur, Belgium
| | - Robert Carleer
- Research Group of Analytical and Circular Chemistry, Institute for Material Research, Hasselt University, Diepenbeek, Belgium
| | | | - Pascal Godefroit
- Directorate Earth and History of Life, Royal Belgian Institute of Natural Sciences, Brussels, Belgium
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4
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Decoding the Evolution of Melanin in Vertebrates. Trends Ecol Evol 2021; 36:430-443. [DOI: 10.1016/j.tree.2020.12.012] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2020] [Revised: 12/18/2020] [Accepted: 12/23/2020] [Indexed: 02/08/2023]
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Yang Z, Jiang B, McNamara ME, Kearns SL, Pittman M, Kaye TG, Orr PJ, Xu X, Benton MJ. Reply to: No protofeathers on pterosaurs. Nat Ecol Evol 2020; 4:1592-1593. [PMID: 32989267 DOI: 10.1038/s41559-020-01309-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Accepted: 08/26/2020] [Indexed: 11/09/2022]
Affiliation(s)
- Zixiao Yang
- Center for Research and Education on Biological Evolution and Environments, School of Earth Sciences and Engineering, Nanjing University, Nanjing, China
| | - Baoyu Jiang
- Center for Research and Education on Biological Evolution and Environments, School of Earth Sciences and Engineering, Nanjing University, Nanjing, China.
| | - Maria E McNamara
- School of Biological, Earth and Environmental Sciences, University College Cork, Cork, Ireland
| | - Stuart L Kearns
- School of Earth Sciences, University of Bristol, Bristol, UK
| | - Michael Pittman
- Vertebrate Palaeontology Laboratory, Department of Earth Sciences, The University of Hong Kong, Hong Kong SAR, China
| | - Thomas G Kaye
- Foundation for Scientific Advancement, Sierra Vista, AZ, USA
| | - Patrick J Orr
- UCD School of Earth Sciences, University College Dublin, Dublin, Ireland
| | - Xing Xu
- Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing, China
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