Integumentary structure and composition in an exceptionally well-preserved hadrosaur (Dinosauria: Ornithischia)

PeerJ

article

Mauricio Barbi¹  Phil R. Bell²  Federico Fanti³  James J. Dynes⁵  Anezka Kolaceke¹  Josef Buttigieg⁶  Ian M. Coulson⁷  Philip J. Currie⁸ 

[1] Department of Physics, University of Regina;School of Environmental and Rural Science, University of New England;Dipartimento di Scienze Biologiche, Geologiche e Ambientali, Alma Mater Studiorum, Università di Bologna;Museo Geologico Giovanni Capellini, Università di Bologna;Canadian Light Source Inc., University of Saskatchewan;Department of Biology, University of Regina;Department of Geology, University of Regina;Biological Sciences, University of Alberta

关键词: Integument;    Preservation;    Skin;    Fossil;    Hadrosaur;    Cell layer;    Synchrotron radiation;    Scanning electron microscopy;    X-ray;    Spectromicroscopy;   

DOI  :  10.7717/peerj.7875

学科分类：社会科学、人文和艺术（综合）

来源: Inra

【 摘 要 】

Preserved labile tissues (e.g., skin, muscle) in the fossil record of terrestrial vertebrates are increasingly becoming recognized as an important source of biological and taphonomic information. Here, we combine a variety of synchrotron radiation techniques with scanning electron and optical microscopy to elucidate the structure of 72 million-year-old squamous (scaly) skin from a hadrosaurid dinosaur from the Late Cretaceous of Alberta, Canada. Scanning electron and optical microscopy independently reveal that the three-dimensionally preserved scales are associated with a band of carbon-rich layers up to a total thickness of ∼75 microns, which is topographically and morphologically congruent with the stratum corneum in modern reptiles. Compositionally, this band deviates from that of the surrounding sedimentary matrix; Fourier-transform infrared spectroscopy and soft X-ray spectromicroscopy analyses indicate that carbon appears predominantly as carbonyl in the skin. The regions corresponding to the integumentary layers are distinctively enriched in iron compared to the sedimentary matrix and appear with kaolinite-rich laminae. These hosting carbonyl-rich layers are apparently composed of subcircular bodies resembling preserved cell structures. Each of these structures is encapsulated by calcite/vaterite, with iron predominantly concentrated at its center. The presence of iron, calcite/vaterite and kaolinite may, independently or collectively, have played important roles in the preservation of the layered structures.

【 授权许可】

CC BY