Demineralised fragments from a Tyrannosaurus rex leg bone contain fibrous areas yielding structures that appear to be cells of a type found in living bone.
No one would expect that after
spending millions of years in the ground, that there would be anything
much in the way of organic material left in fossilised dinosaur
bones. Fossilisation is a process in which animal remains become
mineralised and after the passage of aeons, all that should be left would be a stone
replica of the original creature.
However, at least in the case of a fossilised leg bone of a 68 million year old Tyrannosaurus rex, scientists have been able to extract a flexible organic material which contains structures that appear to be cells and blood vessels. This material was extracted from the bone by dissolving its minerals in a mildly alkaline solution. What was left was stretchy and organic and appeared to contain a network of hollow blood cells. The researchers were able to squeeze out of these vessels tiny red and brown spherical objects which may be blood cells. Also identified were structures that resembled bone-building cells known as osteocytes.
However, at least in the case of a fossilised leg bone of a 68 million year old Tyrannosaurus rex, scientists have been able to extract a flexible organic material which contains structures that appear to be cells and blood vessels. This material was extracted from the bone by dissolving its minerals in a mildly alkaline solution. What was left was stretchy and organic and appeared to contain a network of hollow blood cells. The researchers were able to squeeze out of these vessels tiny red and brown spherical objects which may be blood cells. Also identified were structures that resembled bone-building cells known as osteocytes.
Branching
vessels found in bone matrix of a Tyrannosaurus rex and a modern ostrich.
Although the exact composition of this material is not known, an experiment which involves using antibodies to recognise collagen tested positive and this is a strong indication that some at least of the original proteins do still exist.
These results have since been replicated using the bones of two other tyrannosaurs and one hadrosaur (65 and 80 million years old respectively). All yielded a flexible material which preserved recognisable organic features. This indicates that the current theory that organic material should not last much beyond 100,000 years is wrong and that structures like these may be preserved more often than is commonly believed.
Is there any Dino DNA to be extracted from these bones? Unfortunately this seems very unlikely because the DNA molecule decays extremely rapidly after death, however, on a more positive note, some kinds of protein are known to last considerably longer. Proteins consist of long chains of amino acids and proteins in all living creatures use the same vocabulary of 20 amino acids. Each of these amino acids in turn correspond to a sequence of nucleotides on the original strand of DNA. It is thus possible (in a limited way because this mapping is not without its ambiguities) to work backwards and use the sequence of amino acids to reconstruct the original code of the gene that produced it.
Although the exact composition of this material is not known, an experiment which involves using antibodies to recognise collagen tested positive and this is a strong indication that some at least of the original proteins do still exist.
These results have since been replicated using the bones of two other tyrannosaurs and one hadrosaur (65 and 80 million years old respectively). All yielded a flexible material which preserved recognisable organic features. This indicates that the current theory that organic material should not last much beyond 100,000 years is wrong and that structures like these may be preserved more often than is commonly believed.
Is there any Dino DNA to be extracted from these bones? Unfortunately this seems very unlikely because the DNA molecule decays extremely rapidly after death, however, on a more positive note, some kinds of protein are known to last considerably longer. Proteins consist of long chains of amino acids and proteins in all living creatures use the same vocabulary of 20 amino acids. Each of these amino acids in turn correspond to a sequence of nucleotides on the original strand of DNA. It is thus possible (in a limited way because this mapping is not without its ambiguities) to work backwards and use the sequence of amino acids to reconstruct the original code of the gene that produced it.