Ten years ago, [url=http://www.livescience.com/1410-rex-related-chickens.html]paleontologists discovered soft tissue preserved in a t-rex fossil.[/url] And now again [url=http://www.iflscience.com/plants-and-animals/scientists-may-have-found-red-blood-cells-75-million-year-old-dinosaur-fossil]scientists may have found red blood cells in a 75 million year old fossil.[/url] [b]How is this possible?[/b] Scientists had thought proteins that make up soft tissue should degrade in less than 1 million years in the best of conditions. In most cases, microbes feast on a dead animal's soft tissue, destroying it within weeks. In light of this many argued the tissue must be something else, perhaps the product of a later bacterial invasion. So after this discovery researchers also analyzed other fossils for the presence of soft tissue, and found it was present in about half of their samples going back to the Jurassic Period, which lasted from 145.5 million to 199.6 million years ago. Basically for 300 years it was thought "Well, the organics are all gone, so why should we look for something that's not going to be there?" So nobody did. [b]Fe[/b] Research headed by Mary Schweitzer, a molecular paleontologist at North Carolina State University, suggests iron plays a vital role in this discovery. Iron is highly reactive to other elements, and is plentiful in the body of animals, particularly the blood. The bodies iron is kept bound to molecules that keep it in use, and from wrecking havoc. Upon death though, iron is let free from its cage as the body deteriorates. It forms minuscule iron nanoparticles and also generates free radicals. The iron free radicals cause proteins and cell membranes to tie in knots, basically acting like formaldehyde. The research, which she discusses [url=http://m.livescience.com/41537-t-rex-soft-tissue.html]here[/url], shows a close association with the iron present in the blood and the soft tissue discovered. In the article I linked it discusses experiments they did as well, which could lead to more soft tissue being discovered and tested, unlocking a whole new field of information previously thought to be lost to humanity. Exciting stuff! Fossils we already have could hold all kinds of new information that we weren't even looking for.