US paleontologists have re-discovered traces of collagen and other proteins within the fossilized dinosaur bones, suggesting that traces of organic matter have been preserved for at least 80 million years, according to an article in the Journal of Proteome Research.
“Mass spectrometry technology and protein databases have improved markedly since the publication of our first paper on this topic in 2009. We wanted not only to dispel the questions that have accumulated over this time, but also to show that in the same bones you can and re-find traces of the same proteins with an almost guaranteed chance,”said Elena Schroeter of the University of North Carolina at Raleigh. USA).
In 2009, the world spread the news of an amazing discovery - scientists managed to find traces of protein molecules in the bones of a Brachiolophosaurus, a large hadrosaurus that lived in the United States about 80 million years ago. No one had ever suspected that they could persist for such a long time, and the authors of this discovery were immediately accused of sensationalism, falsification of results and other scientific "sins".
The fact is that simple calculations show that protein molecules remain stable for about one and a half million years, after which all traces of them should completely disappear from the fossilized animal bones. Therefore, scientists believed that the survival of proteins for 60-80 million years is an invention of the authors of this discovery.
Subsequently, other groups of scientists made similar discoveries, finding traces of collagen fibers, connective tissue protein, in the bones of tyrannosaurs and other ancient dinosaurs, and even traces of red blood cells and bone tissue in the remains of several types of ancient giants.
Schroeter and her colleagues decided to prove that the first discovery of proteins was not an accident and that it really happened, using new methods of searching for amino acids inside the fossilized bone matter and the information accumulated over recent years about the structure of proteins and how they decompose.
For the purity of the experiment, as the scientists say, they analyzed not only the bones of the brachiolophosaurus, but also about a meter of the breed that surrounded it, using the highest possible standards of biological isolation when analyzing bones in the laboratory.
A reanalysis of the bones not only confirmed that the scraps of collagen that scientists found in it eight years ago are indeed present in the remains of the brachiolophosaurus, but also showed that they contain six other protein fragments that paleontologists had not previously found in these fossils.
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By combining these segments and analyzing their structure, scientists came to the conclusion that the collagen of brachiolophosaurs was very similar in its structure to similar molecules in the body of birds and crocodiles. This similarity, Schroeter notes, is further evidence that the proteins were indeed preserved inside the bones, and not accidentally found in the samples as a result of their contamination or impregnation with glue.
The re-discovery of proteins and the discovery of new molecules, scientists believe, opens up a whole new area of science - protein paleontology. According to the authors of the article, searching for and studying traces of proteins in the bones of ancient creatures can help us understand how they were related to each other, and uncover the mysteries of evolution that "naked" bones are not able to tell us.