At the top of the occipital bones of the young hypacrosaurus found the chondrocytes (cartilage cells), similar to cells of modern birds, and they are nuclei with DNA fragments, reported in National Science Review. This may indicate that deoxyribonucleic acid persist longer than once thought.
Modern methods allow to detect in fossils aged millions of years, fragments of cells and biopolymers. So, the tyrannosaurs were found in the osteocytes (bone cells), and in them — the remnants of proteins: histones, actin and tubulin. DNA is considered to be less stable and research has shownthat the half-life of molecules of deoxyribonucleic acid length in base pairs 242 — 521 a year. Moreover, this value is determined for a more durable DNA — mitochondrial. It turns out that some millions of years after the death of a living organism in its remains you can only detect individual nucleotides of DNA, but not the molecule.
However, working with the osteocytes of Tyrannosaurus Rex suggests that rather long fragments of deoxyribonucleic acid can be present in the fossil age of tens and hundreds of millions of years. Part of the contents of cells in a dinosaur bone was stained with substances which in contact with two DNA strands.
A group of researchers led by Bellal Alida (Alida Bailleul) did histological preparations of the crushed upper sections of the occipital bone duck-billed dinosaur species Hypacrosaurus stebingeri (age finds — about 70 million years). Judging by the size of the bone, it belonged to a young animal. Another example of the top of the occipital bone of the same length, from different individuals of the same species, were subjected to biochemical analysis, including tried to dye fluorescent dye for DNA.
At the young easier to find cartilage in the composition of the occipital bone, as they, firstly, have a partly cartilaginous in origin (and cartilage as they grow older individuals are replaced by bone), and secondly, these bones due to cartilage fused with neighboring elements of the skull.
The structure of the upper occipital bones of hypacrosaurus compared with that of the same name the bones of the bird EMU the age of 8-10 months. The bones of the other three juveniles was analyzed for content of DNA and other biopolymers. Drugs bones of EMUs and dinosaurs, as analysis of their composition, made in different laboratories to not let so many pollution fossil DNA of modern birds.