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Carl Alwmark

Carl Alwmark

Senior lecturer

Carl Alwmark

Microspectroscopic evidence of cretaceous bone proteins.


  • Johan Lindgren
  • Per Uvdal
  • Anders Engdahl
  • Andrew H Lee
  • Carl Alwmark
  • Karl-Erik Bergquist
  • Einar Nilsson
  • Peter Ekström
  • Magnus Rasmussen
  • Desiree Douglas
  • Michael J Polcyn
  • Louis L Jacobs

Summary, in English

Low concentrations of the structural protein collagen have recently been reported in dinosaur fossils based primarily on mass spectrometric analyses of whole bone extracts. However, direct spectroscopic characterization of isolated fibrous bone tissues, a crucial test of hypotheses of biomolecular preservation over deep time, has not been performed. Here, we demonstrate that endogenous proteinaceous molecules are retained in a humerus from a Late Cretaceous mosasaur (an extinct giant marine lizard). In situ immunofluorescence of demineralized bone extracts shows reactivity to antibodies raised against type I collagen, and amino acid analyses of soluble proteins extracted from the bone exhibit a composition indicative of structural proteins or their breakdown products. These data are corroborated by synchrotron radiation-based infrared microspectroscopic studies demonstrating that amino acid containing matter is located in bone matrix fibrils that express imprints of the characteristic 67 nm D-periodicity typical of collagen. Moreover, the fibrils differ significantly in spectral signature from those of potential modern bacterial contaminants, such as biofilms and collagen-like proteins. Thus, the preservation of primary soft tissues and biomolecules is not limited to large-sized bones buried in fluvial sandstone environments, but also occurs in relatively small-sized skeletal elements deposited in marine sediments.


  • Lithosphere and Biosphere Science
  • Chemical Physics
  • MAX IV Laboratory
  • Centre for Analysis and Synthesis
  • Functional zoology
  • Infection Medicine (BMC)
  • Cell Pathology, Malmö

Publishing year










Document type

Journal article


Public Library of Science (PLoS)


  • Infectious Medicine



Research group

  • Cell Pathology, Malmö


  • ISSN: 1932-6203