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.
Faculty of Earth Science, University of Silesia, Będzińska 60, 41–200, Sosnowiec, Poland;Park of Science & Human Evolution, 1 Maja 10, 46–040, Krasiejów, Poland;Faculty of Earth Science, University of Silesia, Będzińska 60, 41–200, Sosnowiec, Poland;Park of Science & Human Evolution, 1 Maja 10, 46–040, Krasiejów, Poland;A. Chełkowski Institute of Physics, University of Silesia, Uniwersytecka 4, 40–007, Katowice, Poland;Silesian Centre for Education and Interdisciplinary Research, 75 Pułku Piechoty 1A, 41–500, Chorzow, Poland;Silesian Centre for Education and Interdisciplinary Research, 75 Pułku Piechoty 1A, 41–500, Chorzow, Poland;Institute of Material Science, University of Silesia, 75 Pułku Piechoty 1A, 41–500, Chorzow, Poland;A. Chełkowski Institute of Physics, University of Silesia, Uniwersytecka 4, 40–007, Katowice, Poland;Silesian Centre for Education and Interdisciplinary Research, 75 Pułku Piechoty 1A, 41–500, Chorzow, Poland;Institute of Paleobiology, Polish Academy of Science, Twarda 51/55, 00–818, Warszawa, Poland;Department of Histology, Jagiellonian University Medical College, Kopernika 7, 31–034, Kraków, Poland
Recommended Citation:
Dawid Surmik,Andrzej Boczarowski,Katarzyna Balin,et al. Spectroscopic Studies on Organic Matter from Triassic Reptile Bones, Upper Silesia, Poland[J]. PLOS ONE,2016-01-01,11(3)