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Spectroscopic Studies on Organic Matter from Triassic Reptile Bones, Upper Silesia, Poland

Dawid Surmik , Andrzej Boczarowski , Katarzyna Balin , Mateusz Dulski , Jacek Szade , Barbara Kremer , Roman Pawlicki

Published: March 15, 2016


Fossil biomolecules from an endogenous source were previously identified in Cretaceous to Pleistocene fossilized bones, the evidence coming from molecular analyses. These findings, however, were called into question and an alternative hypothesis of the invasion of the bone by bacterial biofilm was proposed. Herewith we report a new finding of morphologically preserved blood-vessel-like structures enclosing organic molecules preserved in iron-oxide-mineralized vessel walls from the cortical region of nothosaurid and tanystropheid (aquatic and terrestrial diapsid reptiles) bones. These findings are from the Early/Middle Triassic boundary (Upper Roetian/Lowermost Muschelkalk) strata of Upper Silesia, Poland. Multiple spectroscopic analyses (FTIR, ToF-SIMS, and XPS) of the extracted "blood vessels" showed the presence of organic compounds, including fragments of various amino acids such as hydroxyproline and hydroxylysine as well as amides, that may suggest the presence of collagen protein residues. Because these amino acids are absent from most proteins other than collagen, we infer that the proteinaceous molecules may originate from endogenous collagen. The preservation of molecular signals of proteins within the "blood vessels" was most likely made possible through the process of early diagenetic iron oxide mineralization. This discovery provides the oldest evidence of in situ preservation of complex organic molecules in vertebrate remains in a marine environment.

Citation: Surmik D, Boczarowski A, Balin K, Dulski M, Szade J, Kremer B, et al. (2016) Spectroscopic Studies on Organic Matter from Triassic Reptile Bones, Upper Silesia, Poland. PLoS ONE 11(3): e0151143. doi: 10.1371/journal.pone.0151143

Editor: Steffen Kiel, Naturhistoriska riksmuseet, SWEDEN

Received: October 8, 2015; Accepted: February 24, 2016; Published: March 15, 2016

Copyright: © 2016 Surmik et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Data Availability: All relevant data are within the paper and its Supporting Information files.

Funding: This research project is supported by National Science Center ( grant no. 2011/01/N/ST10/06989.

Competing interests: The authors have declared that no competing interests exist.