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www.dailymail.co.uk_sciencetech 2015 02247.txt.txt

#Blood and skin cells found on 75-million-year-old dinosaur bones: Tissue was extracted from fossils left in storage for a century Red blood cells and the remains of skin from dinosaurs more than 75 million years old have been discovered by scientists. Palaeontologists found the rare soft tissue on eight dinosaur fossils that have spent more than a century in storage at the Natural history Museum in London. The discovery is expected to result in scientists reexamining other old fossils with modern techniques in an attempt to find soft tissue that may be preserved there. While soft tissue has been found on dinosaur fossils in the past it is extremely rare and has only ever been found in extremely well preserved samples subject to unusual conditions after death. In most cases it was thought the organic tissue like skin, muscle and blood would quickly decay away after death leaving just the harder bones to mineralise and become fossils. But in the latest discovery, researchers found the blood cells and fibres that appear to be collagen-a protein that makes up skin and hair-were found on badly preserved dinosaur bones. Palaeontologists now hope the discovery of the red blood cells could allow them to finally answer questions about the metabolic rate of the extinct animals and help determine how active they were. Scientists have debated long whether dinosaurs were warm or cold blooded, with them often being portrayed as sluggish, cumbersome creatures. By comparing the red blood cells with other species it may be possible to determine relative metabolic rates of the creatures. Dr Susannah Maidment, a junior research fellow at Imperial College London who was one of the authors of the research, said:''Our study is helping us to see that preserved soft tissue may be more widespread in dinosaur fossils than we originally thought.''Although remnants of soft tissues have previously been discovered in rare, exceptionally preserved fossils, what is particularly exciting about our study is that we have discovered structures reminiscent of blood cells and collagen fibres in scrappy, poorly preserved fossils.''This suggests that this sort of soft tissue preservation might be widespread in fossils.''Early indications suggest that these poorly preserved fossils may be useful pieces in the dinosaur jigsaw puzzle to help us to understand in more detail how dinosaurs evolved into being blooded warm creatures, and how different dinosaur species were related.''To conduct their study the researchers, whose work is published in the journal Nature Communications, used scanning electron microscopes to examine eight dinosaur fossils. These included a claw from a predatory theropod and bones from several unidentified hadrosaurs. They used ion beams to slice into each fossil and observe the internal structure of the fossils. They then compared the ancient soft tissue to blood samples taken from an Emu and found that the fossilised material resembeled red blood cells. Proteins are also extremely rare in fossils of this age as they usually break down after around four million years but the scientists discovered what appears to be collagen fibres. If they are able to further analyse the material it may even reveal how it compares to modern animals and perhaps even reconstruct a fragment of the creature's DNA. Writing in the journal, the researchers said they hoped their findings would encourage researchers to reexamine other dinosaur fossils for signs of soft tissue. The said:''Incredibly, none of the samples showed external indicators of exceptional preservation and this strongly suggests that the preservation of soft tissues and even proteins is a more common phenomenon than previously accepted.''Dr Sergio Bertazzo, another author who worked on the study at Imperial College London, said:''We still need to do more research to confirm what it is that we are imaging in these dinosaur bone fragments, but the ancient tissue structures we have analysed have some similarities to red blood cells and collagen fibres.''If we can confirm that our initial observations are correct, then this could yield fresh insights into how these creatures once lived and evolved

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