The possibility that DNA can survive for tens of millions of years is currently not recognized by the scientific community. Rather, based on kinetic experiments and simulations, it is generally accepted that DNA lasts less than a million years. These new findings confirm other findings that suggest that DNA in one form or another can be stored in Mesozoic tissues, and lay the foundation for future efforts to extract and sequence DNA from other very ancient fossils in laboratories around the world. The study is published in the journal National Science Review.
DNA fragments in the cartilaginous cells of duckbill dinosaurs about 75 million years old were discovered by Chinese scientists, March 2, Sina reports.
In the remains of two dinosaurs discovered in the 80s of the last century, scientists were able to detect the remains of cartilage cells with DNA fragments. Previously, scientists believed that DNA molecules could not persist for more than 1 million years. However, the discovery refuted these assumptions.
Now the discovered cells with DNA fragments, scientists plan to subject to a detailed analysis.
Recall that the duckbill dinosaurs lived more than 70 million years ago, the adults of this herbivorous dinosaur reached a length of 9 – 11 meters and weighed up to 7 tons.
Alida Bailleul et al. / National Science Review, 2020
Share Cartilage cells with whole nuclei were visible on sections of the upper occipital bones of hypacrosaurs. The putative contents of these nuclei reacted with fluorescent dyes for DNA. Other dyes revealed the presence of glycosaminoglycans and collagen of the second type. These compounds are typical of the extracellular matrix that surrounds chondrocytes. The same was revealed in emu, whose skulls served as control.
Researchers suggest that DNA was saved for so long that it was in a condensed state – that is, bound to proteins in chromatin. They exclude the possibility of contamination of the bones of hypacrosaurs with “modern” biomolecules, and suggest that under certain conditions it will be possible to find fragments of deoxyribonucleic acid molecules in other fossils of the Mesozoic period.
Also in the fossils of fossil birds and dinosaurs, beta-keratin protein fragments in feathers, structures similar to red blood cells , and amino acids, which are many in the collagen protein , were already found .